Soggy Friday Forthcoming

Just a couple short days after snow fell across the region a strong storm system will work through the region, bringing warmth and a good deal of rain that could result in some stream and roadway flooding in parts of the region on Friday. The system will begin innocently enough with light rain and some showers on Thursday evening before the brunt of the system works through Friday morning with a round of moderate and heavy rain across the region.   The heavier rain will be in association with a warm front that will slowly lift northward overnight, passing Philadelphia after midnight and probably getting as far north as Blue Mountain before low pressure rides east-northeast through the state of Pennsylvania.

Rain will be heaviest until mid morning before it cuts off to just showers, perhaps nothing more than sprinkles across Delaware and South Jersey.   Some computer guidance is suggesting some breaks in the clouds the farther south one goes on Friday, which could result in a marked temperature spread from north to south across the region.

The NAM, left, shows the potential for the warm sector across Pennsylvania, with 50's in light green generally from New York City on south and west through Allentown through Harrisburg and points south during the midday hours.   If we get more than a few looks of sunshine during the afternoon, some 60's would be possible...perhaps even to Philadelphia.   This will be ahead of the low (which you can see as the "target" of those black circled lines in Central Pennsylvania.  As this low lifts northeast, the cold front to its west could perhaps spark a line of showers or thundershowers across South Central Pennsylvania into Maryland, which will slide east with the front.   This isn't a certainty but something to watch with the front.

There are two stories to deal with on Friday.   One is wind.  As the warm front lifts north, southwest winds could increase to 20-30 mph in the mid morning through afternoon, shifting to the west with the passing of the low and cold front and increasing in gusts to 40-45 mph for Friday night and early Saturday.   Friday night's wind will lead to a chilling of the temperature for the weekend -- with temperatures returning to seasonable "norms" for Saturday.

The other story for the event is rain -- some areas could see 2" of rain from this event.   The specifics on who gets what still remain to be seen but it looks like it will be dependent on warm front placement overnight.  Most guidance centers the heaviest rain from Southeast Pennsylvania on northeast through New Jersey.  Whether that is a bit more north of Philadelphia (GFS) or around the city and across Central Jersey (NAM) remains to be seen - but the heaviest of rains should occur after 2 AM on Friday and last until 9-10 AM in the city.   Some minor stream flooding is possible but the bigger threat will be with ponding of roadways and potholes around town, leading to a "fun" Friday morning commute around town.