Nov 14, 2011: Warm Start, Colder Ending To Week

With the ridge in the eastern US still firmly in place, the area observed partly to mostly cloudy skies today with warm temperatures. The model guidance from yesterday, however, underestimated the warmth by as much as 5-10 degrees in parts of the region, and temperatures ended up warmer than expected, peaking in the lower 60s inland, mid to upper 60s in the immediate NYC area, and the mid 60s across most of Long Island and southern Connecticut. Places such as Teterboro and Newark in NE NJ reached 70 degrees, which is over 15 degrees above the average for this time of the year.

With a cold front near the area, tomorrow won't bring any big surprises with the temperatures as mainly cloudy skies are expected with isolated showers possible. A wave of low pressure will move through the area on Wednesday, bringing moderate rain across the area, making this the first significant precipitation event in over half a month to affect the area. Although colder temperatures will return behind, with below freezing lows across most of the area on Thursday night, the cold will fail to last much longer as yet another ridge builds in, bringing temperatures back into the 60s by next weekend.


Tomorrow's Outlook:

Tomorrow will bring mainly cloudy skies as a cold front responsible for producing a severe weather outbreak in the Ohio Valley today moves towards the area. This front will not produce any severe weather or thunderstorms in the area as the front will dry up with no instability over the region, instead bringing isolated showers as the precipitation will focus on a wave of rain developing in the Southeast along this front. With the front's proximity to the area, tomorrow will bring slightly cooler temperatures, peaking in the lower to mid 60s inland, mid 60s in the immediate NYC area, and the lower to mid 60s east of NYC. Places near or SW of NYC may reach the upper 60s.


Wednesday - Friday: Rain Moves Through, Then Colder

The wave of rain affecting the area on Wednesday will be the first significant precipitation event for the area in over half a month, since the late October snowstorm. This storm won't bring widespread heavy rain, although a steady light to moderate rain is expected throughout the day, ending by the evening hours as the front moves to the east of the area and a colder air mass moves in. High temperatures will be chilly due to the rain, peaking in the mid to upper 50s across the area, possibly in the lower 60s in parts of Long Island/S CT and near NYC.

Although a colder air mass will move in, cloud cover will continue through Wednesday night as another weak wave of low pressure develops but stays offshore this time, keeping the rain to the east of the area. With a trough over the region on Thursday, NW winds will bring colder temperatures while producing lake effect rain/snow near the Great Lakes region, resulting in mostly to partly sunny skies and high temperatures peaking in the mid to upper 40s inland and the upper 40s to lower 50s across the rest of the area.

The coldest temperatures are expected for Thursday night, when a high pressure moving into the region will bring mostly clear skies. Low temperatures will drop into the mid to upper 20s inland, upper 20s to lower 30s in the north/west suburbs of NYC and southern CT, upper 20s to mid 30s in Long Island, and the mid 30s in NYC. As the trough starts to exit the region on Friday, the high pressure in place will provide mostly sunny skies with chilly temperatures, peaking in the mid to upper 40s across most of the area with a few lower 50s possible near NE NJ/NYC.


Saturday - Tuesday: Warming Up, Then Cold Front Moves Through


Behind the trough, yet another ridge will build into the region for next weekend. With the high pressure sliding offshore, mostly sunny skies will continue on Saturday with high temperatures reaching the lower to mid 50s across the area. By Saturday night, however, a stronger low pressure will move through the Midwest and into Canada, bringing a snowstorm to places such as Minnesota. This will bring SW winds for Sunday with warmer temperatures, likely reaching the lower to mid 60s across most of the area again. There is some uncertainty with the exact timing of the cold front, but it appears that it should be close enough to the region to bring partly to mostly cloudy skies with a risk of showers focusing around the Sunday night time frame. With the storm staying well to the north of the area, however, any rain associated with the cold front should be light.

Due to the uncertainty with the cold front timing, the forecast for Monday is also somewhat uncertain. For now, I am expecting temperatures to slightly cool down into the mid to upper 50s with a risk of showers towards the morning hours, but the forecast is subject to change, and it is possible that the cold front may trend slightly slower, increasing Monday's temperatures while bringing more of a rain chance. Cooler temperatures are expected to return by Monday night/Tuesday as another transient trough moves into the Northeast, and while the forecast towards the middle of next week becomes more uncertain, several models have been hinting at a potential storm towards the mid week. This is still uncertain, however, and more information will be posted on the outlook for next week, including the forecast for Thanksgiving weekend, over the next few days.


Longer Range: For now, I have not changed my thoughts on the pattern going into early December. My next full discussion on the longer range will be with the final winter outlook, which will include a detailed discussion on the pattern going into December as well as when the pattern may change towards a colder and snowier one.