Weather Rewind, July 10-16, 2011

Temperatures last week averaged 2.6 degrees above where we should be for this time of the year -- locally, we had a four day stretch of 90 degree weather come to an end with the passage of a cool front on Tuesday.  It dragged in marginally cooler air from the west that controlled the weather for Wednesday through Saturday as high temperatures for the last four days of the week held in the upper 80's daily.    All in all, the week's weather was docile but rather warm -- typical for the height of summer.

The one thing we're lacking for a bit locally is rainfall.  Despite a solid inch to two inches of rain last week, our dry spell continues locally as rainfall rates over the past two months are running anywhere from 25% (western suburbs) to 60% of normal in much of the Delaware Valley.   Some parts of the Pinelands are doing ok in the rainfall department as are parts of the Poconos and Catskills up north...however, locally we are running pretty dry and could use a nice widespread rainfall event.

Weather Rewind, July 3-9, 2011

Temperatures last week averaged out to 4.9 degrees above where they should be for this time of the year...thanks mainly to six 90 degree days over the course of the week (which also featured a 93 and 95 degree high in there for good measure) as we had our longest stretch of 90 degree weather so far this year (five in a row).    While most of the week was dry, we did dodge drops on Wednesday (mostly south/east of town), Thursday (a larger portion of the region), and Friday (most everyone) from afternoon thunderstorm development.   Thursday's storms were potent in some spots around today but Friday's had much more bite as the city picked up nearly an inch and a half of rain.

Despite the bonanza of rain in Philadelphia and in South Jersey, areas north and west of town are still quite dry and did not pick up average rains over the course of the week (about three quarters of an inch of rain) -- the northern/western burbs have been in a localized dry spell going back to Spring and despite Friday's rains more could be used locally.   Check out the map below from NOAA for more information on how dry things have been (red shades are less than 100% of normal rain over a seven day period).

Weather Rewind, June 26-July 2 2011

 Temperatures last week averaged a degree above the old averages for this time of the year and once again, we avoid the 90 degree mark locally (running nine behind last year's pace so far) through the course of the week.  The warmest days were last Friday and Saturday, upper 80's for both, but the week with the exception of Tuesday was dry and very nice.   Tuesday brought two different rounds of showers and storms -- one that passed over the city and south around midday and a second that passed across the northern burbs around sunset.   Otherwise, bone dry weather was the rule through the week.

June 2011's temperature profile was a hot one for the Southern Plains and warm for us along the coast (much of that warmth here was from the early stages of the month), with the western third of the country plus the Northern Plains generally cooler than average through the course of the month.   Texas has been atrociously hot and dry since late winter, with June featuring numerous monthly record highs throughout the Lone Star State.

Weather Rewind, June 19-25, 2011

Temperatures last week were warmer than average -- coming in at 3.7 degrees above normal.  No one day was excessively hot or cold, with Wednesday's 92 degree high the only day last week above 90 degrees as the overall weather profile for last week was pretty typical for summer...lots of 80's, scattered thunderstorms on several days, but no heat waves or cold snaps during the week.   The biggest weather story was probably the funnel cloud sightings at a couple of different times last week in New Jersey, along with some scattered storms that caused some damage in parts of the area on Wednesday afternoon.

The operative word with the storms of last week were "scattered" since not all of the region benefited from their rains.  In fact, Philadelphia picked up just 0.09" of rain last week and other areas to the south picked up nary a drop or two of rain through the course of the week.  Allentown, on the other hand, picked up over two inches of rain on Thursday from thunderstorm activity and Reading, just 30 miles away, picked up only four tenths of an inch for the entire week.

Weather Rewind, June 12-18, 2011

Last week's temperatures were nearly where they were supposed to be for the first time in several weeks.   Temperatures averaged four tenths of a degree above where they should be, thanks in large part to  a couple of days with high temperatures in the 70's, which balanced out the 87 we picked up yesterday in Philadelphia.   The relatively 'rare' normal week of temperatures was welcome after getting pummeled with upper 90's the week prior.

We had some showers on Sunday, more showers on Tuesday thanks to upper level energy, and a stronger complex of storms developed and moved through in the late night hours on Thursday night.   Those overnight storms brought nearly an inch and a half of rain to Philadelphia, with one inch totals in spots to the east and south of the city.   Those rains were needed and beneficial; however, we still have a bit of a rainfall deficit locally over the past month (see below) as rainfall over the past 30 days is below average despite a surplus of nearly a half inch of rainfall month-to-date in Philadelphia so far this June.

Weather Rewind, June 5-11, 2011

It was hot again last week overall -- temperatures averaged seven degrees above average locally, buoyed by consecutive record highs in Philadelphia (97 on Wednesday 6/8, 99 on Thursday 6/9).   While neither of those two steambath days topped 100 locally, we did get a 102 out of Atlantic City on Thursday, which was their earliest 100 degree day on record.    These temperatures were eerily similar to those we had three weeks ago at this time -- mid and upper 90's in what was that year's first heat wave of the summer.

We picked up 0.79" of rain last week, most of it on Saturday in three rounds of rain and thunder that moved through the city during the day (one early, one mid afternoon, and a third late at night).   It's a needed round of rain considering the region is running with a rather sizable rainfall deficit the past 45 days.

Nationally, we were not the warmest to average locally.  That honor belongs to the Midwest, where the heat was just as fierce but lasted an extra couple of days compared to here on the East Coast.  Average temperatures in the Midwest and Plains (Missouri and Kansas) were ten plus degrees above average during the last seven days (Saturday through last Friday), with St. Louis picking up four record highs in a eight day stretch along with 90 degree highs for eight days straight.

Weather Rewind: May 29-June 4, 2011

Four days of high octane warmth, including a brush with a record high last Wednesday, fueled a summery 9.7 degrees above average temperature for Philadelphia last week.  Included in the season's first heat wave were some thunderstorms that missed the city by and large, skirting to the north and dropping hail in spots but pretty much leaving the lion's share of the region with little more than sprinkles and clouds.  Other than Wednesday's thunder miss in the city, the vast majority of the region was dry last week.   There were a scattering of thunderstorms on Memorial Day morning across the Lehigh Valley into Central Jersey but a miss for the Philadelphia region as well.

The transition week from meteorological spring into meteorological summer was more July-like in terms of temperatures, despite the late week return to normal in the temperature department.

Nationally, Spring was warmer than average for the southern and eastern 60% of the country, with the west and Northern Plains generally chillier than average, with a rather cold Spring across North Dakota, Minnesota, and Montana.   The core of above average heat was in heart of Texas but much of the Southeast and Mid Atlantic were a good few degrees above average overall.

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.

Weather Rewind, May 15-21, 2011

Outside of Saturday's 81 degree high on what turned out to be a relatively awesome day, last week's weather was not the greatest by any stretch.   Temperatures did average out to 3.4 degrees above normal -- thanks in large part to nights where the low did not drop much -- but with highs generally in the upper 60's or at 70 on three of the days it really didn't feel that warm out, save for Saturday.

Last week felt like weather befitting an ark builder's convention but surprisingly, we're still below normal in the rainfall department for the month in Philadelphia.  Rainfall totaled 1.22" during the week but we're still about nine tenths of an inch below average for rainfall in Philly this month -- other places have seen a good bit more rain this month (as evidenced below in the percentage of rainfall month-to-date) but Philly and points south have dodged the soggy bullet so far.

Of course, the biggest highlight of last week was the weak tornado that damaged businesses in Northeast Philadelphia.   The tornado traveled all of a football field in length and had winds that were not all that strong -- much more typical of what we would see in straight line wind events but because of its cyclonic wind rotation it gets classified as a tornado.

Weather Rewind, May 8-14, 2011

Last week's weather -- well, Sunday to Friday, was about as typical a May week as one could get.   The daily temperatures for the whole week was 0.7 degrees above average, with Sunday through Friday featuring temperatures at or a degree or two above where we should be.   The only cool day of the week was Saturday and even that was only on the daily high side thanks to clouds and occasional showers.   The stretch of 70 degree weather was wonderful...and a wonderful break from what had been a pretty yucky Spring overall.

Nationally, the bubble of nice weather over us translated to a rather warm week in the middle of the country, with record highs in the Midwest and 100 degree weather in the Plains states.   It was cold enough to snow in Denver last Wednesday and the Rockies game was snowed out thanks to an upper level low's cold side bringing a mix of rain and snow to the Mile High City.    At least we were on the good side of the upper level low in the Atlantic and not stuck in clouds and rain this past week.   This week...well, I can't help us on that one!

Weather Rewind, May 1-7, 2011

Last week's temperatures were rather seasonable -- averaging 1.7 degrees above average, all of that thanks to the 83 degree high we scored last Tuesday ahead of a cold front.   The rest of the week averaged out to "normal" overall.   Despite the rather typical week of weather, we did pick up a fair bit of rain in some locations, with Philadelphia getting nearly a half inch of rain on Wednesday in the wake of the cold frontal passage, and other locations getting more than that as showers and storms dotted the landscape not only on Wednesday but also on Friday and Saturday in association with an upper level disturbance that moved through the Mid Atlantic.

Nationally, the only real warmth in the country was found in the Southwest as California and Nevada were quite a bit above average.  The rest of the country featured normal or below normal temperatures overall, with the Midwest the coldest compared to average.   Some parts of Minnesota contended with flurries on Sunday and Monday as temperatures hovered in the low 40's in Minneapolis both days, some 25 degrees below average for this time of the year.

Weather Rewind, April 24-30, 2011

 Our first "80's wave" of the year brought us our warmest week to average so far in 2011 -- temperatures averaging 11.6 degrees above where we normally are in Philadelphia in late April as not only warmth but tropical-like humidity allowed the region, for a few days, skip April, May, June, and linger in July-like mugginess.   Temperatures were as warm as 85 on Monday and until Thursday's 79 degree high, the warmth was the first significant and lasting stretch of above average temperatures we have seen since last Fall.  

There were three severe weather periods this week but those severe weather events were not widespread.   The first was last Sunday as some thunderstorms went severe in Central Pennsylvania and in Maryland.   The second was on Wednesday with scattered tropical thunderstorms that popped up and moved through.  The third was with the cold front on Thursday.   Despite all three events, only 0.09" of rain fell at the Airport although in Wednesday's thunderstorm a quick inch of rain fell in parts of the city.

The warmth -- as we outlined earlier today -- was significant enough to help boost our overall monthly temperatures to the 9th warmest in April since 1872.   April's warmth was most common in the South and Southeast, with the Northwest holding on to chilly conditions.

Weather Rewind, April 17-23, 2011

Another week of the yo-yo in the temperature department ended up averaging us out to just over a degree above average although it was hardly a "typical" week of April weather for half of it.   Tuesday, Wednesday, and Friday were on both sides of the coin, with the first and last of those three days chilly and damp while Wednesday brought us our second 80 degree day of the year as a warm front slid north for a few hours during the afternoon before another advancing cold front put an end to summer's attempts to establish itself.   The most normal days of the bunch were arguably Monday -- sun and clouds mixed up -- and Saturday with its early rains giving way to a mild evening and some sunshine in the late afternoon hours.

Since the Mid Atlantic has been relatively robust in the rainfall department there are very few areas in the Northeast experiencing any dry conditions -- it is generally just a sliver of the Delmarva.  The 0.24% of Northeast real estate in any sort of dry spell is the lowest this total has been in a while and a much different situation than we saw six months ago when much of the Delaware Valley was gripped by dry conditions.  Even compared to a year ago, when we had a very wet February and March in 2010, the region is in better moisture shape...some to our north would argue a bit too soggy, but nonetheless the drought risk for now is very low and nationally confined to the Southeast coast and Texas.

Weather Rewind, April 10-16, 2011

I'll outline the Saturday Soaker in a post later this evening but last week was not only volatile but mild in comparison to average.  Temperatures topped out 3.4 degrees above average for the whole last week, with a high temperature on Monday of 83 degrees marking the warmest we've been since last September 25th and also marking our first official 80 degree high of 2011 in Philadelphia.    Of course, just 24 hours later temperatures were 30 degrees cooler as a cold front sliced through in the early morning hours on Tuesday and a chilly rain moved on through.   The rest of the week was marked by variable temperatures before Saturday's heavy rain event.

Nationally, April 2011 has started out mild to very warm for much of the country to the east of the Rockies, with a trough holding in the West bringing seasonal chill.  The warmth and mild weather have been fleeting in some locations, particularly in the Upper Midwest, as snow fell in Minnesota on Saturday morning.

Weather Rewind, April 3-9, 2011

You can thank Monday's 79 degree high for coaxing an above average week in the temperature department.   Temperatures ultimately averaged a degree above where we "should" be in early April but there was little average about temperatures on Monday, Tuesday, and Friday.   Monday's high of 79 was the warmest we've seen so far this year (although tomorrow may very well change that), with Tuesday's high of 70 occurring at 1 AM in advance of a cold front that brought two rounds of rain through the area, the second of which dropped temperatures twenty degrees in an hour's time in many locations and left a raw, chilly afternoon.   Friday's mid 40's included two-thirds of an inch of rain in Philadelphia on a day more typical of November than April.

Nationally, the brunt of the warmth so far has continued to remain in the Plains and Southwest...which has been the trend for the better part of the last month where temperatures have been significantly above average and precipitation has been next-to-nonexistent.  The trend of a hot, dry Plains summer seems increasingly likely.

Weather Rewind, March 27-April 2, 2011

Besides an April Fools' snowfall that brought anywhere from trace amounts to a couple of inches of snow to parts of the immediate region, last week was quite chilly in comparison to normal.   Temperatures averaged 6.1 degrees below normal in Philadelphia, with the week featuring several days where temperatures couldn't crack 50 degrees -- especially Thursday where the high was just 44 degrees.   We had fair weather to start last week, with a fair bit of sunshine on Monday through early Wednesday, followed by a couple of days of unsettled weather to close out the work week on Thursday and Friday.   While Friday's storm system wasn't as potent as advertised initially, enough upper energy and dynamics helped make for an interesting and wintry morning commute in Chester and Montgomery Counties.   All told, last week's storm brought just a quarter inch of rain to Philadelphia.

March, nationally, was accented by cold in the Northern Plains and drought in the South, which lead to a rather warm month of March in Texas.   Much of the rest of the country was not far from average -- either slightly milder (South, Rockies) or colder (West, Great Lakes)...with the Northeast oscillating between warmth early and chill late.

Weather Rewind, March 20-26, 2011

Last week's temperatures were 3.4 degrees below average as our month long warm spell came to a resounding end after our journey to near 80 degrees late in the prior week.   While temperatures started last week on a relatively mild note (cracking 60 on Monday), cooler air surged south for the latter half of the week as temperatures were consistently several degrees below average from Thursday on.

Precipitation totaled 0.65" last week -- most of it falling on Monday with Wednesday's precipitation totals higher north of the city (where much of it fell as snow north of I-78), accompanied by a round of thunderstorms that brought small hail and sleet to the region during Wednesday evening.  

The pattern nationally saw a pretty decent shift thanks to the development of a -NAO pattern, which helped drive down colder air into the Northeast.  The South is still quite warm thanks to a ridge of high pressure over the Deep South -- a trend that will likely continue in the coming weeks.   The North and West remain chilled for the most part thanks to a rough in the West and the -NAO for the northern tier of the country.

Weather Rewind, March 13-19, 2011

Temperatures last week averaged 7.6 degrees above average -- thanks to a very warm Friday and Friday night (67 degree high at 1 AM on Saturday morning) helping to bump the weekly average up a fair bit.  Friday's 76 degree high was not a record in the city -- although many records were set around the region and temperatures hit 80 in Trenton and Pottstown.   That 76 degree high was the warmest since October 28th (77 degrees that day).   For those keeping track of first 70's...last year's first 70 was on March 19th so we performed pretty much on par with the first 70 degree day although last year's first fling of 70 degree warmth lasted three days, not one.  The end of the week's warmth was a nice cap to a stretch of above average temperatures that generally held serve for the last five weeks.   Now, cooler weather is on the way.

Rainfall was just under seven tenths of an inch last week -- concentrated during Wednesday morning's round of rain.  Some thunder occurred in South Jersey and Delaware with the round of rain as well.

Temperatures month-to-date have been warm across much of the country -- averaging five degrees above average in Philadelphia and warmer than that in the Southwest.  

Weather Rewind, March 6-12, 2011

Last week's temperatures averaged out to 5.2 degrees above average, taking on a typical late March/early April look with temperatures pretty mild for much of the week.  Only Wednesday's 48 and 32 degree high and low, respectively, came in below average on the whole compared to where we need to be (highs around 50, lows right around freezing).   Milder overnight lows (in the lower 40's) certainly help...and the fact that we had two soggy systems bring 2.90" of rain in five days aided thanks to additional cloud cover to help bump temperatures up at night.    While Philly picked up three inches of rain from the storm, some areas to the north and west picked up more, with Mount Pocono's five inches from Thursday's storm more than what we received in both storms combined.

The milder regime that we're experiencing is hitting up most of the country -- with only the Northern Plains experiencing any significant cooling at this point as temperatures there continue to remain a good bit below average.  Fargo, ND, has been ten degrees below average so far this month and still has a foot of snow on the ground.  Rapid City, SD, has been thirteen degrees below average and had a foot of snow on the ground as recently as three days ago...a Chinook wind helped boost their temperatures for a day to near 60 and the snow quickly melted but despite the one day warmth they have been significantly below average.   Outside of that region, most of the country is pretty much at or above average on temperatures so far this month.

Weather Rewind: February 27-March 5, 2011

Last week's temperatures were rather warm overall -- five degrees above average -- as we maintained a generally tranquil pattern as cold air remained bottled up in the Midwest and Northern Plains for the most part.   Temperatures were as warm as 63 on Saturday but also topped 60 on Monday.   Monday's heavy rain "potential" did not materialize as expected, with merely 0.28" of rain in Philadelphia, more to the north and west though as rain and thunder tracked through in the pre-dawn hours.

Some cold air did slip south for a day -- highs on Thursday were just 36 -- the coldest in Philly since February 22nd -- but despite the chilly the plentiful amounts of sunshine during the day made it seem less biting (at least to me).