Saturday, October 12, 2013

Forecast for Sunday, October 13, 2013

Drier air has been trying to work in from the north as an area of high pressure is slowly building in from New England.  This has been successful at breaking up some of the cloudiness for a time today, mainly around and north of Philadelphia. However, another batch of showers and even some embedded thunderstorms is coming ashore. There is a possibility that this batch of precipitation holds together, at least in Southern New Jersey this evening. The precipitation should stay mainly south of Interstates 195 and 76. It may diminish at least somewhat as it encounters the drier air further inland.  Nevertheless, some clouds will be thrown back inland during the night. Also, with the onshore flow, even portions of the northern half of our region could see some low clouds return with the loss of the sun. High resolution modeling suggests some drizzle and showers returning across our northern areas late tonight. So the dry air trying to make progress southward may temporarily lose the battle. Meanwhile, Southeastern New Jersey and much of Central and Southern Delaware, which fall closer to the coastal low, have seen completely overcast skies with periods of showers and drizzle all day. This should continue to be the case into tonight as drier air probably won’t arrive here until sometime on Sunday. 

Blustery conditions will continue into tonight, especially until sunset. The building area of high pressure seems to have been successful at tightening the pressure gradient once again as it tries to send the coastal low pressure system southward. In addition, the peaks of sunshine in some portions of our area are likely are likely allowing for some of the winds to mix down to the surface more efficiently. More efficient mixing also appears to be occurring in and ahead of any showers or isolated thunderstorms. Gusts between 25 and 35 MPH are possible through at least sunset. 

For Sunday, drier air will continue it's attempt to build in. It will likely be sunnier to the northeast and cloudier to the south and west. The pressure gradient should remain tight, so another blustery day is expected. Wind gusts around 35 MPH are possible. With an onshore flow continuing, we can’t promise completely clear skies. Some peaks of sunshine are anticipated here and there, especially later in the afternoon and early in the evening. There is a slight chance for a showers or patchy drizzle in the morning in all areas, particularly south and west of the city. By afternoon, the only low clouds and showers that should be around will be in the far south. But even here, drier air should result in clearing by late afternoon and early evening.

High pressure builds in for Monday and Tuesday. A cold front will approach the region on Thursday and push offshore on Friday. A wave of low pressure may develop along the frontal boundary and this could create numerous showers and thunderstorms during this time-frame along with maybe even a period of steady rain.