Saturday, October 06, 2012

Forecast for Sunday, October 7, 2012

A cold front moving through this afternoon and this evening will be responsible for an increase in clouds across the region. However, while a brief sprinkle or isolated shower cannot be ruled out, most areas will see the front pass through with no precipitation. With the wind shift behind the front, the temperatures should fall steadily and quickly tonight with fifties by late evening in the city and cooler readings in the suburbs. Skies may also actually clear by the middle of this evening into early Sunday with initially drier air.

As the front pushes to our south tonight, a wave of low pressure will move northward along the boundary. Another round of clouds should thicken and lower on Sunday Morning. Most of any sunshine we see, if any at all on Sunday, should be over with by mid-morning. The low pressure area will likely be closest to our region on Sunday and this is when rain will likely develop in our area, especially during the afternoon and early evening. The rain may be heavy at times. Otherwise, it will be breezy and feel raw outside with daytime temperatures in the upper forties and lower fifties. Our high on Sunday will quite possibly be around midnight with highs in the middle to upper fifties. For the Poconos, temperatures could be in the upper thirties and lower forties much of the day on Sunday. Overnight lows and calculating the midnight highs/daytime temperatures relied heavily on the GFS Lamp guidance in my forecast.

The beginning of the week could feature one or two rounds of frost and or freezing temperatures in the suburbs of Philadelphia although there will be some dilemmas to overcome. Early on Monday, if this low pressure area races northeastward, some clearing skies could develop behind it before sunrise.  If the clouds thin, temperatures may drop into the mid and upper thirties before sunrise. I think it is prudent to wait for the Sunday system to get closer before hitting this potential harder in the forecast, but agricultural interests should be monitoring the situation. On Monday Night into Tuesday, another front will move to the coast as a wave of low pressure moves northward along it. It is unclear whether this energy will be far enough north in time to clip our eastern areas with some rain showers and clouds.  This system could be the mitigating factor in a frost and freeze in the Pine Barrens and in other parts of Interior NJ and DE. We may also have to watch out for just enough of an easterly flow to develop low clouds and drizzle east. Meanwhile, north and west, where less clouds are expected, there is a higher chance of frost with even some spotty freezing temperatures by sunrise on Tuesday.

For Wednesday Afternoon and Evening into very early on Thursday, a cold front will move through the region. Most of the energy and precipitation looks to go to our north and this passage should only contain some widely scattered showers late. Behind it, expect breezy conditions as it will be driven by a pretty potent low pressure area which will tighten the pressure gradient as high pressure builds in for Thursday through Saturday. The next storm system could arrive by Sunday or Monday.