Not Quite A Broken Record

There are a couple of ways you can look at today's high temperature of 94 degrees as not quite a broken record.   First, it was warmer today than yesterday as the slight bit of relief promised by some of the higher resolution modeling did not verify.   The power of the heat ridge won out over a weak backdoor front that never quite got through the region.    The other way is that the record high of today, 97, did not get hit.   We missed the mark again by only a few degrees.   It is the third 90 degree day of 2011 so far and with tomorrow another probable 90 we will get ourselves a heat wave out of this stretch of warmth as it will be the third in a row.

Around the area, records were tied or made in Baltimore (hit), Scranton (tie), Reading (hit), and Wilmington (tie).   It was close in Allentown (two degrees off).   Most everyone except coastal sections and the Poconos hit 90 or higher today, some places were a couple of degrees warmer than yesterday.

June 1st, 2011 Forecast

Tonight: Warm and muggy under partly cloudy skies. Lows will drop between 67 and 72 degrees across the region. Winds will be out of the south-southeast at 5 to 10 mph. The sunset tonight is at 8:22 PM.

Wednesday: Assuming we get to 90 degrees or higher by the end of the afternoon today, Wednesday should complete heat wave # 1 of the 2011 summer season. Remember, a heat wave in Philadelphia is defined as 3 consecutive days at 90 degrees or higher. It will be hazy, hot and humid on Wednesday with strong to severe afternoon thunderstorms developing. 3 PM to 9 PM will be the time frame to watch for thunderstorm development. Expect a high near 91 degrees in Philadelphia. Winds will be out of the southwest at 5 to 15 mph with gusts around 20 mph. The chance of rain is about 40 percent.

Thursday: Sunshiny skies, less humid. The high will be around 85 degrees. It will be a breezy day with wind gusts near 30 mph.

Friday: Bright sun, beautiful. Look for a high near 82 degrees.

Wednesday Planner

7 AM 72 degrees, Hazy

Noon 86 degrees, Humid

5 PM High near 91 degrees, Strong Storms

Sunrise 5:35 AM

Sunset 8:23 PM

Chance of Severe Storms Tomorrow

The Storm Prediction Center has the region under a slight risk for severe weather on Wednesday as the heat wave/heat event that we're currently dealing with comes to an end with the passage of a late day cool front and the weakening of the heat ridge over the Eastern US.    This is another less-than-optimal setup for severe storms in that some parameters are rather impressive while others are screaming against severe storms.

The items for severe are the heat, humidity, and the development of a trough along the eastern edge of the Appalachians thanks to a wind shift line between west winds coming downhill and southwest winds at the surface, as well as temperature differences between the mountains and the lower elevations in Southeastern and South Central Pennsylvania.   That trough develops in the late morning and early afternoon and acts as a focal point for at least scattered afternoon thunderstorms.   These storms, given a fast wind environment aloft, could bring damaging winds and perhaps some hail, as they move east towards the region.   The NAM, below, shows the thunder threat generally between 2 and 5 PM around the region, earliest to the west and northwest and latest across Delaware and South Jersey.   The timing element is generally consistent across all major models -- generally the early and mid afternoon time frame around the region looks the most likely for any thunderstorm development to occur.

What is working against severe is the potential for surface winds to shift westerly a bit sooner and preclude any trough development downstream of the Appalachians.   A west wind is typically not good for severe storm development in our world and even a southwest wind may keep thunderstorm development more scattered and less widespread.   However, with temperatures in the 90's and dewpoints in the 65-68 range there's more than enough heat and humidity to provide the fuel for something to pop.

Hot weather...

The heat is getting up into oppressive levels across the region. Highs today and tomorrow will surge up into the mid to even upper 90s, and heat index values will surpass 100 degrees in some locations.

Several record highs will likely tumble over the next couple of days across the region.

A weakening front will drop into the region late tomorrow and kick off a few showers and storms. In the very unstable airmass we will have in place, a few storms could produce some hail or damaging winds.

All in all, more Summertime weather will continue through the weekend and into early next work week with more 90s for highs and a few pop-up PM storms possible.

Please check on those you know that do not have access to air conditioning....this is a fairly significant early-season heat wave.

Stay cool.....

Hot Memorial Day

Today's high temperature of 93 degrees (as of 5 PM) is our second 90 degree day of 2011 and the warmest of the year to date.   Heat and humidity abounded throughout the region today, even in areas that were hit by the early morning thunderstorms.   Those storms probably prevented a 90 degree day in Trenton and Allentown but there's no real difference between 89 and 90, is there?

Philadelphia's 93 approached but did not exceed the record high of 97, set back in 1991.

A couple of records were knocked out in the Mid Atlantic -- Baltimore's BWI Airport hit 98 degrees today and Georgetown, Delaware topped out at 95.   The Georgetown record was from just a few years ago while the Baltimore record was from 1991.

May 31st, 2011 Forecast

It's hot and humid today in the Delaware Valley -- perfect to spend the day at the beach, shore point, or near some body of water.   The heat will continue for the next couple of days, not as humid tomorrow but still plenty warm around the Delaware Valley.

A weak trough will slip south this evening and try to ease cooler air in from New England.   While the surface wind trajectory will be light from the east and northeast tonight and tomorrow, we have a rather strong ridge of high pressure aloft that will keep the atmosphere plenty warm.   The heat ridge should be able to compensate for the attempt at a backdoor front, especially inland where temperatures will again runs towards and past 90 degrees.   East of I-95, however, it might be a few notches cooler during the day and the seabreeze may have a much easier time of marching west during the afternoon.   Expect 80's east of the city, 70's at the Shore tomorrow afternoon.  Everyone should be mostly sunny tomorrow.

We'll be starting Tuesday with mostly clear skies and morning lows in the upper 60's in the coolest burbs, mid 70's in the city.   A pop up storm or two can't be ruled out across the Poconos or Central Pennsylvania's higher hills.

Memorial Day...

Take some time today to reflect and honor those that have fallen defending our country....ensuring the life and liberty we get to enjoy on a daily basis.

Heat will be the word this week....lots of 90s for highs....a few spots might try to make a run at 100. A little better chance of some daily afternoon storms arrives Wednesday onward.

Enjoy the day....

Thundery Start For Some, Heat Will Arrive For All

The complex of thunderstorms that we talked about last night aiming for northern parts of our region took a trip down across the Lehigh Valley early this morning and are working through Central and North Jersey, plus visiting Bucks County at this hour.   They are in association with a weak atmospheric disturbance traveling around the heat ridge in the atmosphere, with the storms poised to continue their movement to the southeast over the next hour and eventually off of the coast.   For those north of I-195 and even into Burlington and Southern Ocean County in Jersey, thunder will be a part of the early morning.

Everyone will get into the heat, except right at the Shore, later on today as these storms push on through and sunshine returns in the next few hours.  High temperatures should climb into the lower 90's for many locations, with temperatures near 80 at the Shore.  Combine those temperatures with dewpoints in the 60's and heat index values will be close to 95 later on today.   Heat Advisories are out for today for the Philadelphia metro, with an Excessive Heat Watch out for Tuesday as we *could* see hotter temperatures tomorrow.

Some isolated pop up thunder can't be ruled out later on this afternoon but the odds of that occurring have decreased a fair bit thanks to this morning's line of thunderstorms crossing the northern and eastern parts of the area providing some stabilization to the atmosphere.

Potential Storms Passing Just North Late Tonight?

I mentioned earlier today in a couple of posts  that areas north of Philly could see some late night thunder tonight.   Here are those storms on the radar/surface map up above, currently situated in Ohio and Michigan.  They have pummeled parts of Michigan with tornadoes and strong wind and are working into Lake Erie and across the northern parts of Ohio.   The southern flank of these storms -- generally the stuff that's working south of Lake Erie -- could graze northern parts of our area late tonight and early on Memorial Day morning with a round of loud thunder as these work east along the northern periphery of a subtropical ridge of high pressure.   The subtropical high brings us our upcoming heat and humidity event from Monday through Wednesday, with weak disturbances working along the northern edge of the high and producing thunderstorms with them.   If you've heard of the 'ring of fire' term thrown around before this is somewhat similar to a ring of fire setup since the "fire" in the form of thunderstorm complexes are usually associated with atmospheric disturbances.

The higher resolution modeling (below) shows the potential for those storms to survive their trek east tonight and cross parts of the region as day breaks on Monday.   Timing could be a bit earlier than what the high res is suggesting -- my thought is any thunder that we get works across the region a little bit earlier than 6 AM but it could be a bit damp out at daybreak in the Poconos and perhaps the Lehigh Valley.

Weather Rewind, May 22-28, 2011

It was a rather warm and summery week overall around town as the average temperature ended up 7.6 degrees above average, with Philadelphia getting its first 90 degree day of the year on Thursday and six consecutive days of 80 degree warmth here in the Delaware Valley.   We finally shook the precipitation pattern of last week, although it took until Wednesday to finally do so.   The average temperature, if one throws out the marine-layer influenced Sunday, was closer to nine degrees above average in the period from Monday through Saturday.

Last week's weather was also stormy in spots, especially in Central into Northeastern Pennsylvania as thunderstorm complexes developed and lifted northeast in advance of a frontal boundary that could not quite reach the region.   That same system was the storm system that dropped the powerful EF-5 tornado in Joplin a week ago today.

The localized warmth of May 2011 (temperatures now approaching three degrees above average for the month) is part of the warm pattern that has generally set up for the Northeast and Mid Atlantic, which are one of the only parts of the country to see above average warmth overall.   The coolest to average is in the Northern Plains and Northwest so far this month.

Memorial Day 2011 Forecast

Summer's unofficial start has been accompanied by warmth.   The end of the first weekend will bring heat as temperatures will nudge 90 for the second time this year and begin the first heat event of 2011.   Upper level ridging of high pressure will help warm us up and a surface high off of the Carolinas will push warmth northeastward at the surface.  It's the "perfect" mix for heat and temperatures will respond in kind over the next few days.

With the northward advance of the heat ridge, we could see a complex or two of thunderstorms develop across the Great Lakes this afternoon and push east along the ridge's northern fringe tonight.   It's possible some thunderstorms could pass through the Poconos and Northern Pennsylvania, perhaps extending down into the I-78 corridor, later on tonight.   For those who don't get storms, it will be a muggy night around town.

Memorial Day features a push of temperatures into the 90's, with humidity levels high enough to push heat index values into the mid and upper 90's away from the coast.   A weak disturbance will try to push into the ridge of high pressure, which will act as a trigger for pop up thunderstorm development in the afternoon.   Some storms will be locally strong but it will not be a widespread event.   Temperatures at the Shore will nudge 80 with increasing humidity.

Week Ahead:   Tuesday could be the hottest of this week as temperatures could reach 95 degrees under mostly sunny skies and the continued influence of the heat ridge.   A frontal boundary will push southeast from Canada, crossing the region on Wednesday evening with a threat for strong and severe thunderstorms as the front will bring a respite from the heat.   Temperatures behind the front may not reach 80 by the time we get to Friday, with the weekend starting off rather nice but potentially ending stormy.

The First Signs of Returning Heat

The region is waking up to a warm morning again, with the upper levels now about to warm up in a big way to help set up the season's first heat event.   Today marks the transition day as we're seeing some clouds around this morning, with a few showers to the north and northwest of Philadelphia.   Those showers will stay safely away from the city but we do have some clouds at various levels in the atmosphere early this morning.   As the sun works its late May magic and the upper level ridge continues to slowly exude its influence, the clouds should thin and a healthy dose of sunshine should break out.

Summery cumulus clouds will pop up later on and while a thunderstorm can't be ruled out later on today, the vast majority of the region looks dry this afternoon and evening as the necessary triggers for thunderstorm development are not great and are generally going to be localized and isolated in nature.    One thing that marks the transition to a heat ridge in many instances is nighttime thunder and that is in the forecast, especially for our friends to the north as a complex of thunderstorms may roll across the northern fringes of the heat ridge (along and north of I-80?) after Midnight tonight.

The heat is definitely "on" tomorrow -- highs should top 90 in many locations away from the coast.   Today probably doesn't get quite there but mid and upper 80's are definitely doable.

Blast From The Past: Twenty Memorial Days Ago

Much like this year, Memorial Day 1991 was a hot and humid one in Philadelphia.   Temperatures topped out in the mid 90's on a sweltering day that was a part of a seven day heat wave in Philadelphia to close out the month of May.   A much younger Monica Malpass and Susanne LaFrankie did a weather update during Good Morning America, with a much younger Charlie Gibson anchoring on GMA as well.

The May '91 heat wave was one of the strongest early season heat events we've seen around here and 1991 was the gold standard year for heat until 2010 knocked that out of the park.

LaFrankie, for those who did not know, is no longer working in the TV realm.   She's a business and communications consultant in a joint partnership firm that is located here in the Delaware Valley after spending some time at WPHT after her Channel 6 career ended.

Forecast for Sunday, May 29, 2011

Outside of a very isolated thunderstorm, Sunday is looking like a very warm and humid day. Temperatures should rise well into the eighties. Some of the most robust modeling shows portions of the urbanized areas in the interior flirting with 90 degrees. Morning fog will burn off and the sunshine will come out mixed with cumulus clouds in the afternoon and early evening. Fog may return Sunday Night, late before burning off Monday Morning.

A cold front is expected to approach the region on Monday Afternoon and Monday Evening. The latest model guidance has suggested more in the way of thunderstorms with this system as it moves through the region from the Lehigh Valley to the coastline. Strong surface heating and high dew points should lead to impressive surface based CAPE and steep lapse rates. Temperatures could rise into the lower nineties with some locations having the chance to reach as high as 95 degrees. Scattered thunderstorms are possible with the potential for some to become severe with damaging winds and large hail on Monday; which is also Memorial Day. With outdoor barbeques and other events, the timing of the thunderstorms is of concern. The NAM is a bit more bullish than the rest of the guidance, but has handled the convection well lately.

Heat index values on Monday will easily be in the 95 to 100 degree range. Some of the urbanized sections of the interior have the potential to have a few hours of heat index values of 100 degrees or greater.

The other thing I will be watching is the spike in electricity usage due to the hot temperatures, especially at the shore. For the past several days the shore has been consistently cooler than the interior with a southeast wind. This wind will shift more southwest on Monday, probably ending the break from the heat along the coastal communities. Like some of our big summertime holidays at the shore last year, the combination of more people than usual down at the coast for the holiday period (resulting in high usage) and heat resulted in some localized blackouts.

On Tuesday, it will be another hot and humid day. Temperatures could be slightly cooler behind the weak front from Monday. 90 to 93 degrees sounds reasonable at this point. Another pop-up thunderstorm is possible, but there will not be a real focus on Tuesday across most of our region. North and West of Philadelphia probably will be closest to the cold front moving in from the west for Wednesday.

On Wednesday, this is when we could see some pretty intense and nasty thunderstorms. A strong cold front will approach the region on Wednesday Afternoon and Wednesday Evening. The front will bring an end to the hot and humid weather conditions with significantly less humid and cooler conditions waiting behind the boundary. While not all the time, thunderstorms usually breakout when such heat busts occur. The model guidance does hint at a weak wave forming along the front as it moves through with some pretty good areal coverage of thunderstorm activity. For our forecast…showers and thunderstorms are likely and some could be severe. A good section of the region is under a risk for severe weather in the Day 5 severe weather outlook by the Storm Prediction Center. There are no slight, moderate, or high risk categories in the extended severe weather outlook.

Hit & Miss Thunder Later Today

A lurking, dying frontal boundary will provide enough spark for scattered afternoon and evening thunderstorms across parts of the region. Today, like the last couple of days, will not be a wash out for areas impacted by thunder as any storms that pop will do so after midday. However, any outdoor activities that are going on may have a rain delay or two as storms pop up and move north-northeast along the frontal boundary this afternoon and early this evening.

The best chance of thunderstorm activity will be along and west of I-95 today but it will be scattered in nature. NAM modeling (up above) shows that this afternoon into evening could feature some localized heavier rainfall over northern parts of the region with the strongest of storm cells but these stronger storms should be fewer in number than yesterday, which featured less intense storms overall compared to Thursday.   There is no slight risk (as of this morning) for severe weather in the region but that doesn't mean that a storm can't become severe, however.   The strongest of storms could bring some hail and gusty winds but with the dynamics of the past two days not as favorable and the frontal boundary dying these storms should generally be more "run of the mill" and not of the type that drops two inch hail.

For those that don't get thunder'd upon, temperatures will top out in the mid 80's away from the ocean, 70's at the Shore.   Not a bad day at all if you happen to avoid getting a storm or two.

Storms will taper off after sunset, with another chance of pop up storms on Sunday -- this time the storm threat will generally reside to the north of us in the afternoon tomorrow.

More:   Current Weather Page

Thunderstorms To Our West (Again)

Update, 4 PM:   Heat and humidity abound around town as many of us get away for Memorial Day weekend, with a severe thunderstorm watch out to our west.   Radar at this point is showing thunderstorms starting to light up with thunderstorms south and west of State College, with scattered storms across Central Pennsylvania's higher hills.   Storms, like yesterday, will move northeast over the coming hours.   One area of thunderstorm activity that may work its way into parts of the region late this evening is currently over Virginia and lifting north-northeast along the slow-moving (and weakening) frontal boundary.  Some of that activity, in a weakened state, might get into parts of Central Pennsylvania and perhaps the far western burbs after 10 PM.    Temperatures across the region this afternoon range from 82-88, with heat index values a few degrees higher as humidity levels are not quite as high as they were yesterday.




Includes Berks, Lehigh, Northampton, Carbon, Monroe, and Lancaster Counties in our area. Damaging winds and large hail are the primary threats, although an isolated supercell could produce rotation and allow a brief tornado to develop. Expect scattered thunderstorms to initiate shortly. Some 2" diameter hail cannot be ruled out.

There is about a 20 to 30 percent chance of a severe thunderstorm, isolated in nature, forming to the east of the watch. The majority of activity will be closer to the stalled cold front and therefore, we should not see widespread storms in the eastern areas.

Probability of 2 or more tornadoes: Low (20%)

Probability of 1 or more strong (F2-F5) tornadoes: Low (5%)

Probability of 10 or more severe wind events: High (70%)

Probability of 1 or more wind events > 65 knots: Mod (30%)

Probability of 10 or more severe hail events: Mod (50%)

Probability of 1 or more hailstones > 2 inches: Low (20%)

Probability of 6 or more combined severe hail/wind events :High (90%)

Surface based CAPE Values range from 1,500 J/kg to 3,000 J/kg across our region. Derecho composite values are 3 to 4. Downdraft CAPE is 900 j/kg to 1,200 J/kg. Low level lapse rates of 7.5 and mid level lapse rates of 5 to 7.5 are quite steep suggesting large hail is likely in addition to damaging winds. All and all...where a thunderstorm can fire..it has plenty of opportunity to attain severe limits anywhere in the region, even outside the watch.

Memorial Day Weekend Forecast

Some years have featured some rather unremarkable Memorial Day weekend forecasts -- temperatures in the 60's, clouds, and rain.  This year is much like last year's Memorial Day weekend -- warm, becoming a bit toasty on Memorial Day itself as a heat ridge begins to build in over the East Coast.    A weakening frontal boundary will lurk over the region on Saturday, providing scattered thunderstorms for the afternoon and evening hours in any one location.   Thunderstorms should not be an all day event but some spots could receive a couple of rounds of storms before the day is out.   The boundary dissipates on Sunday but there could still be a pop up thunderstorm or two to deal with in the afternoon as a push of warm air moves northeastward.

Memorial Day is shaping up as the warmest of the three days and the day with the lowest precipitation chances -- temperatures will flirt with 90 away from the Shore with plenty of sunshine and increasing...but not oppressive...humidity.   Each day will generally be nice but Monday will have the lowest odds of rain of the three, with Saturday featuring a scattering of thunderstorms around the region (again, not enough to kill outdoor plans altogether but enough to cause "rain delays").

Highs inland for Saturday and Sunday will be in the mid 80's, with lows each night in the 60's.   At the Shore, highs all weekend and Memorial Day will be in the 70's, with lows in the mid 60's at night.

We'll be around to update the weekend weather forecast for you throughout the holiday weekend.

Showers and storms today...

Some pretty mean storms moved up from South Carolina into portions of North Carolina last evening. Numerous severe thunderstorm warnings were issues, and a tornado warning was required for parts of York, Gaston, and Mecklenburg counties.

A good number of folks are still without power as of this typing....over 7k in both Gaston and Meck counties...over 8k in York. Lots of reports of tree damage as well.

Today, we are in a soupy airmass, and we will have disturbances trigger showers and storms at times. It will not rain all day, but we are fair game to see a shower or storm at any point today into tonight. Highs today will be held down...probably low 80s at most for the I 85 corridor.

The storm system will simply fall apart as the Memorial Day weekend unfolds. So, a few storms are possible tomorrow, but I then think many spots will be dry through Sunday and Monday. The heat will build with lower 90s again by Memorial Day.

It still looks hot Tuesday and Wednesday with highs likely well up into the 90s....but then we get into a northwest flow aloft for the second half of the week, meaning the heat will back down and some storms are possible.

Foreshadowing of Summer

The region this morning is waking up to a warm and muggy conditions, with temperatures near 70 in the city and in the mid/upper 60's in many of the surrounding burbs. Like yesterday, we should make another run at 90 degrees this afternoon and the combination of heat and humidity will make it feel a few degrees warmer.   For those heading out to start Memorial Day weekend activities at the Shore or your favorite vacation spot, it will feel quite a lot like summer here in the Delaware Valley today.

Yesterday's severe weather events in Central and Northeastern Pennsylvania were pretty rare in terms of hail size (three inch hail is teacup size, just a bit larger than baseball) for this part of the country.   The dynamics that drove yesterday's hail and wind events in Central Pennsylvania aren't quite as robust today as they were yesterday but you have enough ingredients in the severe weather pot (frontal boundary, lift, warmth, and moisture) to produce more scattered strong and severe thunderstorms this afternoon across western and northern sections of the region.

A slight risk for severe weather is out for areas to our north and west -- much like yesterday in coverage area -- and thunderstorms today should generally be more numerous to the north and west of the city than the south and east.  The strongest of storms could bring wind and hail that are severe criteria, with thunderstorms developing after 2 PM and generally tracking northeast.

More:   Current Weather Page

Tea Cup Size Hail Tonight: Rare In Pennsylvania

Tonight, Pennsylvania saw a rare weather phenomenon. Hail 3.00” in diameter or the size of “tea cups”. According to the National Climatic Data Center, since 1950 (when records were first kept by them), there was only 11 previous reports on file of 3.00” diameter hail or larger. Tonight, there were three reports of 3.00” diameter hail in Carbon County, Pennsylvania.

The largest hailstone to ever occur in Pennsylvania was back 1956 in Beaver County when 4.50” hail was reported. There are three reports of 4.00” diameter hail on file which were received in 1980 and 2010. There is also one report of 3.80” diameter hail that was received in 1994. The other 6 of 11 were 3.00” hail reports which were reported in 1960, 1967, 1974, 1983, 1996, and 2010.

Tonight’s reports occurred in Summit Hill around 7:06 p.m. Two reports were received in the community of Lansford around 7:06 p.m. and 7:10 p.m.

Of course, hail was not the only problem this evening. Damaging wind gusts caused numerous trees and power lines to come down in parts of the Lehigh Valley and the Poconos. Whether any brief tornado occurred within the swath of damaging winds will be considered by the National Weather Service if any reports of significant damage are received.

Tens of thousands have been left in the dark from Southwestern Pennsylvania into Southern New York by the large hail and damaging winds…and even a few suspected tornadoes that we know of in Central Pennsylvania.

Turning the Big 9-0

Update, 8:30 PM: The severe cell that was situated over South Central Pennsylvania a few hours ago has developed into a squall line of thunderstorms from New York State south into Lancaster County.   This cluster of storms is moving northeast and will graze the northern and western parts of the area over the next few hours.   It would not be a surprise if the outflow boundary from the storm complex works into the Philadelphia metro and provides some gusty winds before 10 or 11 PM as the outflow moves east and the storms move northeast.   The biggest threat with the squall line at this point is damaging wind, particularly for areas north of I-78.

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For the first time this year, Philadelphia hit 90 degrees and with the relatively high dewpoints out and about it definitely feels summery in the immediate Delaware Valley.  Heat index values are in the mid 90's thanks to dewpoints in the lower and even middle 70's.   The warmth will linger through the night and continue into tomorrow as a slow moving frontal boundary approaches from the west.

Radar (up above) depicts thunderstorms that have developed out in advance of that slow moving boundary -- generally scattered in nature and generally across Central Pennsylvania.  The storms are generally lifting northeast and will stay generally west and north of the Philadelphia region and its suburbs.   Berks and Lehigh could get grazed but odds lean against it.     To our west, a tornado watch is up until 10 PM for the threat that any of the storms that develop not only become severe but also develop tornadoes.   None of the counties in the Philly region are under the watch -- it comes as close to us as Lancaster County.   One storm cell in particular -- across Western Maryland -- has produced golfball sized hail and doppler indicates hail to baseball size within the cell.   It also has some rotation with it.   That storm will not hit the Philly area.

More:   Current Weather Page

May 27th, 2011 Forecast

Today's thunder threat to the west will be our thunder threat tomorrow.  The front that acts as a boundary for those thunderstorms to travel to the north and northeast will ease into the region and stall out, prevented from finishing its march to the sea thanks to the developing upper level high to our south that is bringing us warmth.  The front will provide a pop up afternoon thunder threat for the next three days around the region as it fizzles into little more than a trough around the region.   While temperatures may nudge down a few degrees over the early portions of the weekend as the upper level high relaxes slightly, it will be a good bit above average in the temperature department as we start the weekend.

Scattered storms that develop this afternoon generally stay in Central into Northeast Pennsylvania, perhaps grazing the Allentown or Reading areas with a storm cell or two.  Philly should stay dry, but warm, tonight.   Expect lows across the region between 65 and 69 degrees.   Friday will be pretty much a repeat of today, with a couple of 90 degree readings possible around the region.    The only difference will be that aforementioned thunder threat for the region as scattered afternoon and evening thunderstorms could develop and move through.    Winds both tonight and tomorrow will generally be from the south.

Memorial Day Weekend Sneak Peek:   Saturday and Sunday feature more pop up thunderstorm potential as the frontal boundary fizzles out.  Overall, it will be a nice weekend but plan on the potential to have rain delays at outdoor events, parties, and the like as a storm could pop each afternoon across the area.  We're not expecting widespread thunder each afternoon -- just scattered, hit or miss variety.  Highs on Saturday and Sunday will generally be in the 80's inland, with Monday featuring another run at 90.   At the Shore, expect 70's all weekend long for highs.

More warmth today....showers and storms tomorrow...

It was another pretty hot day across the region Wednesday, and again, the hottest temps were in the Sandhills and Coastal parts of the region.

Some select high temps...

Erwin: 99
Lumberton: 98
Fayetteville: 98
Laurinburg: 98
Wilmington: 97
Ft. Bragg: 97

Highs today will again warm into the low to mid 90s in many spots...maybe just shy of that in the Triad region.

It was indeed a big severe weather outbreak yesterday in the Ohio and Mississippi Valley areas. Here is the storm report map.
That system continues to crawl our way, weakening as it does so. Some storms are possible this afternoon in the mountains and western Upstate, but for the NC Piedmont, the chance of showers and storms should mainly arrive this evening and tonight with the bulk of the activity taking place tomorrow.

A few severe storms are possible with this system, but it will not be the same animal it was earlier in the week.

For the Memorial Day weekend, a few storms can't be ruled out Saturday and Sunday, but most spots will likely be dry. Highs by Sunday and Monday will return to the upper 80s and lower 90s.

I still expect some pretty hot weather through mid-week next week, but there are indications that the big ridge might shift to the western US by the end of the week, meaning a northwest flow here.

Heating Up Today In More Ways Than One

Our first real run to 90 starts today -- not everyone will get there but many locations will flirt with the "vaunted" demarcation of heat this afternoon as the first fingers of the heat ridge that will be with us for much of the next week build in over the region.   The best chance of 90 degree readings will be at the typical 'warm' sites like Pottstown and Northeast Philadelphia, places that typically run a degree or so warmer than everyone else.  Humidity levels will be a notch higher than yesterday and it will feel somewhat humid out -- not oppressively nasty in the humidity department but it will definitely feel like a summery day as we get ready for the Memorial Day weekend.

The warmth is out ahead of a frontal boundary and storm system -- the same storm system  that is responsible for all of the severe weather that raked across the Midwest and the Great Lakes yesterday.   This system will work northeast and the trailing front will slow in its approach, rebuffed by the upper level high building to the south and east of it.   As a result, while a slight risk of severe weather is out for much of Pennsylvania it does not include the immediate Philadelphia area as we should coax a thunder-free day in the immediate city.    Thunderstorms will pop up, however, to our north/west in the afternoon and lift northeast, some of which will bring large hail and damaging wind.   There's a 30% risk of severe criteria in wind and hail near one's location per the Storm Prediction Center in Central and Northeast Pennsylvania, generally to the west and north of I-81.   Given this storm system's propensity to produce tornadoes, those can't be ruled out in Central PA later today as well.

Storms could glance into the Lehigh Valley and Berks County but even there the storm chances are not that high, at least compared to farther west and north.    Again, this should avoid the immediate area today...probably won't tomorrow as the front moves in.  The dynamics tomorrow won't be as good as the surface low is farther removed but the presence of the boundary combined with heat and humidity will make for scattered storms again tomorrow.

More:   Current Weather Page

Memorial Day Warmth Forthcoming

It's going to be a summery Memorial Day weekend, very similar in many respects to last year's weekend when we saw our first 90 degree day of many in 2010.   A summery pattern is generally kicking in starting tomorrow, which offers the outside chance of a 90 degree day in Philadelphia as southerly winds nudge northward and we stay on the warm side of a frontal boundary.   That front fizzles upon crossing the region on Friday night and Saturday, leaving a lingering boundary around on Saturday that could spark a thunderstorm.

The boundary essentially falls apart due to a strengthening upper level ridge of high pressure in the South, which will flex its heat muscle and push warmth up the East Coast.  The ridge weakens slightly on Friday and allows the surface front to push through and brings us scattered thunder chances in the afternoon, with only an outside chance for thunder on Saturday afternoon as the boundary fizzles away.

We could see a thunderstorm any afternoon over Memorial Day weekend but temperatures will be warm -- mid 80's on Saturday and Sunday afternoon, low 90's on Monday as the ridge strengthens further and high pressure entrenches at the surface off the Carolina coastline -- providing an optimal path for heat and humidity.   The Shore will be cooler but still summery -- 70's for highs each afternoon east of the Parkway, 80's west of it.   There could be a seabreeze that pushes further inland each afternoon but by and large it should be a nice weekend.   Again, each afternoon or evening could present an outside chance for thunder but much of the holiday weekend will be awesome.

May 26th, 2011 Forecast

Warmth and humidity will be a common theme in our weather over the next several days as the first signs of a summery heat ridge build into the Mid Atlantic starting tomorrow.  The weak frontal boundary that crossed through last night with little more than a whimper is fizzling and warmth will push northward in advance of a storm system that will itself fizzle on Saturday as it finally crosses the region.  That storm system, however, will throw a thunder threat into the region for Friday as the front gets close enough to the region to trigger thunderstorms.   This system is the same one responsible for the nasty severe weather outbreak on Tuesday in the Plains.

Tonight should be mostly clear and comfortable with lows generally between 60 and 65 across the region.   Expect Thursday to be warmer than today, more humid as well, with highs generally in the mid and upper 80's, with the Shore in the lower 70's thanks to southerly winds at 10-15 mph.   There could be a few thunderstorms late in the day far to our west and northwest (Central Pennsylvania) as the front nudges towards the region but the city and immediate area should stay dry and mostly sunny.

We'll talk about the Memorial Day weekend weather in a post later on this evening.

Storm system crawling our way...

First of all, some impressively-hot high temps in eastern parts of the region yesterday, including...

Fayetteville: 98
Lumberton: 98
Wilmington: 97
Erwin: 97
Laurinburg: 97
Manteo: 92

Also, there were some pretty mean storms in northern NC and southern VA, and numerous severe weather warnings were required.

At the same time, another huge severe weather outbreak was unfolding in the Plains, and that continued overnight. Unfortunately, it was another deadly tornado day and night.

Today, the big severe weather threat is in the Mississippi Valley region....and again, some strong tornadoes could be involved.

For our region, while a few isolated storms are possible, I expect most spots to remain dry with highs in the low to mid 90s...maybe some upper 90s again in eastern NC.

Our best shot at showers and storms will come Friday as that system, albeit in a weakened state, moves in.

A few storms could linger Saturday, but then I expect mostly dry weather Sunday and Monday with highs in the upper 80s and lower 90s.

It still looks like the heat will really crank for a while next week in much of the central and eastern US.

Warm, Murky Spring So Far

I've had a few folks who have commented about the lack of 90's so far (and I have as well) and in some cases, have commented on the lack of typical Spring weather.   Believe it or not, we've been above average on monthly temperatures since February.   Obviously, the weather hasn't been that nice out but we have managed a few things that have favored warmer weather this Spring.

1) When we've been warm, it's been quite warm above average -- four straight days of 80 and above high temperatures in April, a spike into the mid 70's for a day in March have done wonders to average temperature departures despite the occasional cold snap.  Our average high temperatures this Spring (62.8 degrees) are more above average (2.6 degrees) than our average nighttime lows (1.5 degrees).   Those warm days...and warm early mornings that have provided as an extra "warm day" in a warm shot have helped provide a bit of added insurance to make up for the occasional cold day.

2) The chill has been short but potent.   Yeah, it snowed on April Fool's Day.  Yes, it was cold and rainy at various times in April and even into early May.   However, those cold days were predominately in late March and early April -- and generally only a few degrees below average on each of the days (40's and low 50's for highs, 30's for lows compared to average temperatures in the upper 50's and low 40's for high/low respectively).   April had a few cold days but they were short snaps in duration, with May generally mild (although cloudy and rainy for the most part).

Compared to last year,  we are a couple of degrees cooler in average temperature (56.2 in 2010 versus 53.7 this year) but believe it or not, we had yet to see a 90 degree reading to this point last year.  The first of those 55 90 degree days occurred on Memorial Day last year...and it's possible Philadelphia could hit 90 this year before the end of May, with Friday possibly ending up as that lucky day for our first 90 degree reading of the year.   The good news is we probably won't have 55 more days in the 90's before year's end -- the bad news for those who hate heat is that we'll have more than one in all likelihood.

Not So Thundery Tonight

Our evening snapshot of weather is rather tranquil locally outside of a severe thunderstorm a couple of hours ago in South and Central Jersey.  We've been "blessed" with unfavorable low level winds and a modestly dry lower atmosphere thanks to those westerly winds drying us out at the surface.   This is despite favorable upper level dynamics and the trigger in the form of a weak cold front.      You can see that boundary slipping south on radar across Pennsylvania -- generally along I-80 across the state at this hour.   Unfortunately for storm chasers, the best support for thunderstorms is farther west and by the time those storms work towards our region, well after sunset, they may very well weaken enough to be a non factor locally.   The storms farther south, across West Virginia and south of Pittsburgh, might clip parts of the Delmarva later on this evening as they work east-southeast.

We alluded to the downer in today's severe weather potential being the westerly winds and that ended up being the bane in today's severe weather prospects...not that anyone is complaining.

Temperatures today were quite warm around Philadelphia, topping out at 86 degrees in what is our warmest temperature so far this month.  Today's high actually missed a record by just four degrees (record last set in 2004 and originally set in 1964).   This evening...and the next several days...will be quite warm as a ridge of high pressure builds aloft and we make a run at 90 later on this week.

Tornado Watch...

A Tornado Watch is in effect for northern NC and southern VA late this afternoon and this evening. There is just enough shear and plenty of instability to support the chance of a few brief tornadoes in this area. Stay with News 14 Carolina for all of the latest weather information.

At the same time, the big tornado outbreak is underway in Oklahoma...already large tornadoes on the ground, and I am afraid this is the beginning of another violent tornado outbreak.

May 25th, 2011 Forecast

Tonight: Strong evening thunderstorms are possible in any location across the region. Damaging wind, heavy downpours, and large hail will be likely if any of the thunderstorms become severe. Lows will drop between 59 and 66 degrees from northwest suburb to city. West-southwest winds will shift from the north-northwest overnight, 5 to 15 mph. The chance of rain is about 60 percent. The sunset tonight is at 8:17 PM.

Wednesday: Any leftover morning cloudiness should give way to mostly sunny skies. Another warm day, but not as warm as Tuesday, with a high near 83 degrees in Philadelphia. The Shore points will hold between 68 and 74 degrees for highs, due to ocean water temperatures between 65 degrees (Atlantic City) and 69 degrees (Cape May). North winds in the morning will shift from the west, 5 to 15 mph. Wednesday should be a dry day.

Thursday: Hazy sun and more humid with a 30 percent chance of a pop-up storm. The high will be around 86 degrees.

Friday: Hazy, hot and humid with a 30 percent chance of a pop-up storm. Friday is likely to be our first 90 degree day of the year. I am expecting a high near 91 degrees in Philadelphia.

Wednesday Planner

7 AM 66 degrees, Clouds to Start

Noon 79 degrees, Mostly Sunny

5 PM High near 83 degrees, Warm

Sunrise 5:38 AM

Sunset 8:18 PM

Warm And Potentially Thundery

It's a warm and humid start to the day around the region -- localized fog has developed in spots that received some rainfall last night (mainly to the north and northwest of Philadelphia where the brunt of severe weather ended up taking place as well).   That fog should lift relatively quickly this morning since it's not a marine-induced fog, which will leave us with a mix of sun and clouds around the region for the mid-morning hours on.  Some storms can't be ruled out this morning as a weak disturbance ahead of the front tracks through and could trigger a shower or storm in spots.   This shouldn't zap the atmosphere too much and we should see a few hours of brightened weather.  Sunshine may be a bit of a premium in spots but there's enough warmth in place in the atmosphere to allow temperatures to get into the 80's away from the ocean.

It will be a warm day for most of the region and with a weak cool front approaching from the west we have the potential to see more showers and thunderstorms popping up around the region.  The Storm Prediction Center has the Philadelphia area under a slight risk for severe weather this afternoon and evening as the main batch of storms should develop to our west later on today and move into the region generally between 3 and 6 PM.   Fortunately for us, we're not in the highest of risk areas as a high risk is out across the Southern Plains today -- specifically Oklahoma City, Wichita, and Tulsa -- as a tornado outbreak is distinctly possible out there this afternoon and evening.   Here, gusty winds are the biggest culprit in any severe weather that does develop and one can't rule out the risk for a brief spin-up tornado in the strongest of storms.

Radar modeling (above) shows the potential for those storms this afternoon into the evening -- again, the models are generally suggesting they move into the area between 3-6 PM although there is some variation between the faster (NAM/GFS) and the slower (higher res) modeling.   Also, despite more heat and humidity locally compared to yesterday the one "downer" on severe chances is an unfavorable surface and low level wind flow (more westerly than the more ideal south-southwesterly).  It may result in a more scattered approach to thunderstorms as opposed to one solid line.   However, unlike yesterday storms should do a better job of holding together as they approach Philadelphia or track east into South Jersey.   Just something to keep in mind -- it may be a case where not everyone gets impacted, like yesterday, but those that do may get hit with some pretty potent thunder late this afternoon.

More:   Current Weather Page

Get used to the heat and humidity....

Well, looks like we have kind of settled into this pattern for a while. Around the I-85 corridor, high clouds held temps down a bit yesterday, but I don't expect that today, and most highs should top 90 degrees. Raleigh topped 90 yesterday, and in the Sandhills, highs warmed into the mid 90s. Highs will remain in the low to in some spots mid 90s through Thursday.

Interesting to note a little MCV (mesoscale convective vortex) over eastern Arkansas this morning. It if survives, that would move into the Carolinas this afternoon. All in all, I expect a few afternoon storms, and while most spots will likely remain dry, the storms that do form will pack a punch with some gusty winds, hail, and lots of lightning.

A few PM storms remain possible tomorrow and Thursday, then look for a better coverage of storms for Friday.

See the video below for details about the 'high' risk of severe weather to our west today. I also discuss our weather ahead, including a possible continuation of the hot and humid pattern for much of next week.

Severe Thunderstorm Coverage

Severe Thunderstorm Warning for Kent County in Delaware...the storm has a history of producing golf ball size hail in Maryland and radar continues to detect it until 9 o'clock.

Severe Thunderstorm Warning for Hunterdon, Morris, Somerset, Sussex, Warren [NJ] and Northampton [PA] until 9:30 PM. Doppler radar has indicated a thunderstorm capable of producing destructive winds in excess of 70 MPH. Forks Township clocked a wind gust to 68 MPH according to the National Weather Service.



Tornado Warning for Hunterdon, Warren [NJ] and Bucks, Lehigh, Northampton [PA] until8:30 PM EDT

In addition, the National Weather Service radar is indicating hail to 2.00" in diameter! This is a dangerous situation.

Bath, Bethlehem, Nazareth, Old Ochard, Tatamy, Glendon, Wilson, Easton, and Forks will be impacted by this possible tornado and destructive hail.








At 7:40 p.m. local law enforcement reported a circulation with this storm above the ground! Folks reading our coverage in the warned area should move into a basement immediately!



Tornado Warning for Carbon, Lehigh, Monroe, Northampton until 8:00 P.M. In addition to the tornado, damaging winds and 1.00" diameter hail is likely with this thunderstorm.



Tornado could impact Walnutport, Coffeetown, Northampton, Beersville, and Bath during the next 15 minutes!

Move into an interior closet or basement! Stay away from windows!

Monday's Storm Discussion

Update, 6:45 PM:  Eastern Lancaster and Southeastern York Counties are under a severe t-storm warning until 745 PM. Doppler radar has also indicated some weak rotation in this storm according to the statement.

Update, 6 PM:   Storms are generally along and just east of the Susquehanna River, with a couple of pop up cells near Reading and near Chester respectively.  The main line extends from just west of Lancaster to Bloomsburg in North Central Pennsylvania.   All of that is moving east and northeast and is probably a couple of hours away from Philly and should cross the city by 9 PM (or so).    The Severe Thunderstorm Watch in Central PA was extended a couple of hours, now out until 8 PM for the counties in Central Pennsylvania.    Winds could gust to 45 mph with the storms and some vivid lightning can't be ruled out as well.

Update, 4:50 PM: SPC will be coordinating a new watch box along and east of thunderstorms between 5 p.m. and 6 p.m.

Update, 4:30 PM:   Storms are starting to pop up across the region, with a tornado warning up between Harrisburg and State College for a storm that will track a good ways north of us.   Closer to us, showers and storms are popping up near Lancaster and north of Baltimore, lifting northeast.  This activity, plus the storms out west of York and in Northern Maryland, will be the activity to track over the coming hours as it moves east.    The best odds of severe thunderstorms will generally reside along and west of I-95.










If you look at the temperature profile on the map above you can see that there is still some residual cool air lingering to the north and east of Philadelphia, with temperatures in the 60's across Bucks and into North Jersey.  Severe chances will drop off quickly as the storms reach and breech the Delaware River later this evening thanks to the stable air in place.   That doesn't mean a severe storm can't occur but the odds there are a good bit lower than they are in Chester, Lancaster, or in Berks Counties where the sun has been out a bit more this afternoon.

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Across the region this morning, clouds have been hanging tight. On the latest satellite imagery, we are starting to note clearing in the southwestern portions of our region, moving up from Baltimore and Washington D.C. This area of sunnier breaks will continue to push northeast with the warm frontal passage into the early afternoon hours. I think the breaks will at least make it through Philadelphia and South-Central New Jersey.





The Storm Prediction Center this morning increased the percentage that severe thunderstorms would occur within 25 miles of a point in the western portions of our forecast area. 30% probabilities have been given to the western sections of our area. Due to the satellite depictions of where the breaks are beginning to occur, this seems to be very reasonable as these areas will be into the sunshine for the longest duration prior to convective development. With the clearing skies expected to make relatively good progress through the remainder of our area, the 15% probability for severe weather or the percentage that warrants a slight risk designation has been moved to include the rest of us not in the 30%.



Basically, this is how it works. 2% for tornadoes or 5% for damaging winds/large hail warrants a “see text”. A 15% or 30% for large hail/damaging winds or 5% or 10% for tornadoes warrants a “slight risk” designation for severe thunderstorms. A 45% for large hail/damaging winds or 15% for tornadoes warrants a moderate risk for severe thunderstorms.

With the warm front rising just above our region and the potential sunshine moving our way, we are in a very favorable quadrant for severe thunderstorms. Most times warm fronts do not have enough energy to produce much more than isolated convection to the south of the boundary. However, this is one of those scenarios where a wave of energy will ride along the front to cause the activity to be more widespread than usual. A similar situation developed last year when a warm front made it up to Southern New York and a severe threat developed (including tornadoes) in Northeast Pennsylvania and Northern New Jersey after sunshine developed. This is the concern I have for today. No doubt that this event will be driven by destructive sunshine.