Thursday, February 23, 2012

In Between Systems, Mild Continues

We hit 60 yesterday in Philadelphia, the second time this February we've breached that plateau and likely not the last.  Today and tomorrow will duke it out for the honor of the warmest day in this Spring Fling; however, today shapes up as the likely "nicer" of the two days...meaning it will be a less rainy day.

Last night featured a few rumbles of thunder across South Jersey and Delaware as there was some atmospheric instability present with showers that moved through to our south overnight.   We could have a few more showers around this morning as a weak frontal boundary lurks to the west this early morning.   As that front crosses, showers will push through (best chances north of the Turnpike in PA, 195 in NJ) and breezes will shift around to the west and increase to between 10 and 15 miles per hour, perhaps with gusts over 20.  Most of the region should break out into some sunshine for a time...the sunniest areas will be Philly on south later on today, with more clouds to the north as a bit of lurking cool air tries to slip south and help fire up more clouds.

In terms of temperatures, today's highs will depend on location.  The map above shows the 4 AM temperatures where 40's lurk north of the Turnpike (some 30's as well in the coolest of spots), with temperatures near 50 degrees from Philly on south.   Today's highs will be coolest north (55-60 north of the city) while warmest south (low 60's city and most of South Jersey, mid to upper 60's in Southern Delaware).

I mentioned we are "in between systems"-- today's first and weaker system depart, with the stronger second storm moving in later this evening.  The weak frontal boundary from this morning's system lurks across the region, with rains breaking out along and north of the frontal boundary this evening as warm air aloft pushes northeast.  Rain will spread east, with best chances north and northwest of the city.  Rain could be steady for a time and it wouldn't surprise if a rumble or two of thunder accompany tonight's rains in spots.  It also would not surprise if there were a burst of snow over the Southern Poconos on the front end of tonight's rains as they move in -- odds of anything more than a nuisance coating to inch or two are pretty low, however, as the surge of warmth pushing in from the southwest is strong enough to transition you over to rain up there.