Showers Later Today

A cool start in the region this morning will give way to a cool and showery late afternoon as rain is several hours away and to our west. Temperatures that are in the 30's and low 40's around the region will rise into the lower and middle 50's before showers move in and yes, some frost can't be ruled out this morning as you walk out to your car...especially in Allentown and Quakertown where temperatures are close to the freezing mark.

Radar below shows the areas of rain and showers off to our west -- a larger shield of rain extends from Erie back west to Illinois, while a second area of showers exists in West Virginia and a wider area of rain exists back near St. Louis.  All of this precipitation will move east and through here for tonight and tomorrow morning.   Some areas could pick up an inch of rain, particularly to the city's north, as a warm front slowly trudges on through the area.  

Flooding shouldn't be an issue considering the rainfall is longer duration -- but it will be a soggy night and Saturday morning for the region.   Par for the course in this rainy, slow to develop Spring.

Some Rain This AM, Some Thunder This PM

Showers and a steadier band of rain are moving in from the west this morning with a warm front at the surface and aloft helping to charge up the atmosphere, creating some lift above the ground and helping to enhance precipitation across Pennsylvania.    For the most part, precipitation is falling in a liquid fashion as temperatures are in the lower 40's in many locations across the immediate area.   Some sleet is mixing in farther north and northwest (where the precipitation banding is brighter in color) but even up in the northern parts of the state, temperatures are above freezing except in the higher elevations so slick travel doesn't seem all that likely.   Some sleet could mix in with the heavier precipitation as it works through later on -- especially the farther north one resides, with the Poconos seeing a bit of snow possible on the highest of hills.   Around the city that won't be an issue with today's event.

We should see this first round of rain work east through the region this morning -- there will be a couple of lulls in the rain as there is a break in it back in Central PA but we should see off and on showers through late morning before we get into a more substantial break in the precipitation after 10 or 11 AM.   The aforementioned warm front will clear the region and we'll reside in the "warm sector" for a few hours.

Despite seeing temperatures nudge higher, clouds may linger through much of the afternoon as the push of warmth at the surface isn't as strong as it is aloft.   Given the rain from this morning, we may have some junk cloudiness hang around for the afternoon and as a result temperatures may just get into the upper 50's by day's end.   The more sun we coax out of today (the big wildcard), the higher the temperature ultimately goes.

At the same time, if we do get a bit more sunshine, we could see some thundershowers pop along a southward slipping cold front late this afternoon.  The best chance for these will be across Western and Central Pennsylvania but a few sunshine dependent rumbles of thunder could slide into Southeast PA just after dinner.   We'll see if those pop -- don't hold your breath...if they do, they shouldn't be severe but could kick up some breeze.

More:   Current Weather Page

Nature's Alarm Clock Late Tonight?

With tonight's half inch to one inch rain event moving on through later tonight Brian alluded to the potential of some isolated thunderstorms embedding within the rain. Yeah, Mother Nature may wake you up later tonight with some thunder as low pressure pops along I-95 and enhances the precipitation towards daybreak.

Looking at high resolution radar above, the potential for thunderstorms could occur anywhere in the area.  Given the track of the low, the best chances for thunder may occur along either side of the low pressure center.  If the low does indeed pop along I-95 and take a trip up the interstate (not literally of course) the thunder chances would be across the metro.   An eastward jog in low track may send those storms along the coast or across South Jersey.   Rainfall should be steadiest/heaviest between 2 and 8 AM, quickly tapering off as the low lifts northeast and generally over with by midday if not slightly before.  

Nothing severe, nothing earth-shattering...but you might wake up a bit earlier than you would like if Ma Nature has her way.

More:   Current Weather Page

The Train of Rain

Track The Storm On Our Current Weather Page

This morning's radar shows rain -- and lots of it -- across Pennsylvania and interior portions of the Mid Atlantic.   Off and on light rain has fallen in Philadelphia overnight -- not much, as expected, since the lion's share of the event will take place this afternoon and tonight.   Computer modeling is still painting a rather robust event -- two to three inches of rain on the GFS, two to four inches of rain on the NAM for Pennsylvania, with one to two inches of rain east of I-95.   This type of rainfall will yield flooding for many streams, particularly to our north and west.

Expect light rainfall this morning before rainfall becomes steadier -- and then heavier -- during the afternoon hours.  This steadier/heavier rain may take a while to reach the Shore but during the evening hours we should see the entire region get hit with a couple of rounds of heavier rain.  Higher resolution computer modeling (below) shows the bulk and brunt of the storm comes this evening and tonight.  Rain continues to spread northward, increasing in intensity, while a cold front approaches from the southwest (marked by thunderstorms that may develop across Virginia and the Carolinas) and crossing the region in the pre-dawn hours on Friday.

This is a longer-duration storm than we're used to -- the storm will also not be as bad this morning as it will be this evening, which means flooding problems may start overnight in earnest as opposed to during the day on local streams and roadways.

We'll probably set daily rainfall records today (generally between 1.25 and 1.70 inches regionwide) and have an outside shot at the single day rainfall record for March (for Philly, 2.79").   While the combined event total may exceed three inches, it is quite possible that enough of that will fall on Friday in the pre-dawn hours to keep us just shy of the single day record.   No matter how you slice it, it's a lot of rain...and it will be pretty ugly out there by this evening.

Updating Sunday's Rainy Weather

A malaise of gray and mildness today ahead of Sunday's soggy storm system that will bring a period of rain through the region, with some of that rain becoming rather heavy and causing stream flooding or water ponding on roads.  Flood Watches have been issued for Pennsylvania, Northern New Jersey (effectively north/west of the Turnpike from Trenton on north), and points north as the potential for some flooding does exist due to soggy ground and the potential of some heavy rainfall.

Sunday's event is looking like it will bring a rather significant amount of rain, once again, to our west, with areas east and southeast of Philadelphia getting the lower rainfall totals -- a half inch of rain or less is certainly not out of the question in Southern Delaware while parts of the Poconos or Lehigh Valley could see a couple of inches of rain.   The rainfall disparity is due to the track of low pressure with this storm.   While the primary low responsible for the cold front will track into Canada, a secondary low will develop on the frontal boundary and track northeast starting later today and intensify on Sunday.  This low will effectively track along or just northwest of I-95 from Raleigh through New York City into New England.   Areas to the east of the low track will see lower rainfall totals -- but could get some thunderstorms on Sunday afternoon as the low lifts in -- whereas west of the low track could see some steady to heavy rainfall starting Sunday morning and continuing until just after the low lifts past.

An example of the rainfall disparity is shown above -- the Euro is really socking Pittsburgh, Erie, State College, and Scranton with lots of rainfall while there's a pretty sharp cutoff once one gets to Philadelphia and even less rain falls to the east and south.  This trend is reflected in the other guidance as well -- although the GFS and NAM are hinting at a rainfall "bullseye" in the Poconos of 2-3" of rain (which the Euro is not).

Timing-wise, expect some spotty drizzle today while rain spreads east overnight tonight, hitting the western burbs by sunrise and spreading into the Philadelphia area during the morning hours.  South Jersey will be the last to see rain move in.   Some patchy showers can't be ruled out before the steadier rains hit on Sunday.   Since we will end up on the "warm" side of the storm for the most part -- temperatures in Southeastern Pennsylvania and New Jersey will stay mild tonight and Sunday, possibly staying in the low 50's in Philly overnight tonight.

Soggy Storm System For Sunday

Most computer guidance is in clear agreement about the next rain event moving in on Sunday -- potentially setting up as a soggy storm system for parts of the region if guidance holds serve over the coming days.   The GFS and EURO both dig a trough down in the Midwest along a frontal boundary, with low pressure organizing along the front and moving east-northeast or northeast, depending on the model.  The two models bring the storm system through starting late Saturday night and early Sunday morning, with the bulk of the event during the midday or early afternoon hours.   There's still some difference in the specific timing on the frontal passage (which will probably be when the rain cuts off) but both models indicate most of Sunday will be rainy.

Like last Monday's event, which was full of computer modeling fail from a precip forecast standpoint in our area, the computer models again are suggesting the heaviest rainfall will be to the north and west of Philadelphia.   Parts of Western, Northern, and Central Pennsylvania could pick up close to 2" of rain if things pan out.   Around here, a half inch to an inch looks pretty likely at this point, with the most rainfall across the Lehigh Valley and Berks County.

Some thunder can't be ruled out with this storm as well, especially on the eastern side of the low track.  If the GFS verifies, the best chances for thunder will be across Delaware and South Jersey (closer to the low) whereas with the Euro the low track is farther west (towards Pittsburgh and Erie) and thunder chances would exist for everyone but would generally be confined to the frontal passage in the afternoon.   It doesn't, for now, look like there would be any severe weather potential with the front, but some thunder could move through...

Ahead of the front, expect temperatures in the 50's to low 60's on Sunday -- very Spring-like but the soggy factor will make those milder temperatures a bit less enjoyable.