Thursday, September 19, 2013

Saturday Night & Sunday's Shower/Storm Primer

Our next shot of precipitation is on Saturday night into Sunday with a cold front that will slide through the region. This front brings an end to the near 80 degree weather that will be expected on Friday and Saturday through the region.

Most of Saturday should be dry throughout the region, with an increasing risk of showers and storms late in the day to our west, advancing eastward through Saturday night and into Sunday as the front pushes east.  Given the relatively slow movement of the front and that showers and storms will push northeast in the flow ahead of the front, it could yield the prospect of some heavier rain in some locations on Saturday night.  Based on modeling, it looks as if the Poconos and Central Pennsylvania have a chance of some heavier downpours...not flooding type rains, mind you, but if anyone can pick up over an inch of rain from this system it looks as if those locations have a shot.

Sunday does not, at this point, look like an all-day washout. It does look damp in the morning hours with the front overhead but the front should slowly push east through the day. Showers will gradually taper off from west to east as the day progresses, yielding some dry weather in the afternoon for Pennsylvania and by evening in New Jersey. We could see some sunshine as well by day's end...but it may very well start wet.

Odds of severe weather with this system appear very low at this point.

One feature we are keeping an eye on that may interact with the frontal boundary is down in the Gulf of Mexico this morning. This area of disturbed weather is in the Bay of Campeche and is expected to be pulled northwest towards the Mexican coastline over the next couple of days.  It has a decent chance to develop into a tropical entity of some sort (Jerry is the next name for a storm on the list).

This system has been modeled to pull towards the Mexican coast and then move inland, with moisture from the storm system drawn north and then northeast by the cool front, perhaps interacting with a developing mid level trough and creating a cutoff feature off of the Southeast coast early next week.  The Euro has been relatively aggressive and consistent in keeping this feature on the map...although waffling mightily in placement and track.  The GFS, which at one time had the system relatively close to us as well, has weakened the potential system dramatically and now just produces a strewn-out mess of showers and storms along the Gulf Coast early next week.

At this point, the earlier "hype" of a large soaking rainstorm that the Euro and a couple of other models had painted 24 hours ago for us and the Shore looks to have subsided somewhat as high pressure seems to build in fast enough to suppress any developing cutoff storm.  Just in case the stormy scenario that was outlined a day ago trends back, we will keep an eye on it but it was an outlier then and most modeling has generally shied away from such a scenario locally.