NY NJ PA Weather Forecasts

Evening Thoughts

There’s a lot of topics I want to cover tonight so lets dive into it!

First and foremost, the heaviest rainfall from this afternoon’s coastal low is now off the coast and I only expect a few light showers and some drizzle for the rest of the overnight period.  There is plenty of deep moisture still left over the forecast area that is streaming out of the Gulf of Mexico.  As winds begin to veer to the south and southwest from the surface to 500 MB by the morning, a warm and humid air mass will build into the forecast area.  Weather conditions will resemble spring like conditions through much of the day on Friday.  Given that humidity will fall below 50% at 700 MB, I think there will be some breaks in the cloud cover, however plenty of low clouds in the morning will lead to a mostly cloudy day through tomorrow afternoon.

Meanwhile, a strong disturbance will amplify the 500 MB trough on Friday evening as a new area of low pressure develops over the Tennessee Valley and tracks towards central New York by Saturday morning.  A strong cold front will follow with a developing thermal gradient of 8 to 12 degrees from the East coast to the Ohio Valley.  The dynamics setting up over the forecast area will support embedded elevated thunderstorms over the forecast area on Saturday.  Don’t be surprised if some of the thunderstorms briefly reach severe levels, especially with strong down burst wind gusts.  Rain cooled air will rush down to the surface in these thunderstorms and produce strong wind gusts, possibly to 50 mph in isolated locations.  The cold front will clear the forecast area by Saturday evening with temperatures crashing through the 40’s.  

So now the cold front has passed and the pattern has evolved, what will the new trough hold for the forecast area?  The answer is winter like conditions.  First, expect temperatures to be on average 8 to 12 degrees below normal through much of next week.  Second, a series of small yet potent disturbances from the northern branch will race through the forecast area.  Overall, these disturbances will not have the potential to produce wide spread, heavy precipitation.  However, given the strong lifting of these disturbances and the 850 MB temperatures remaining well below zero throughout the forecast area; the forecast area will have the potential for snow showers Tuesday through Thursday.  I think the best potential for this in the evening hours and likely over the northern Pennsylvania, northern New Jersey, the Hudson Valley, and Connecticut.  

Now, lets get to the topic that is raging on all the weather boards out there!  Is the ECMWF really forecasting a returned Southeast ridge and a blow torch pattern for the end of November.  Remember what I said way back in October, do not trust nor jump on one model run or even a few model runs in the long range.  Remember, the models in the long range are dealing with an atmosphere with very weak signals, and you can bet the GFS, ECMWF, and ensemble guidance will continue to forecast a variety of solutions.  This is why those who hug models are going to get serious burned this winter, in my opinion.  I can promise all of you that from run to run, no matter the model, that the hours of 192, 210, and 240 will show everything from blow torches to monster blizzards from run to run this winter.  

As I explained this morning, I think the pattern will relax during the beginning of the last week of November.  The northern jet stream can not stay amplified forever, and thus a relaxation in this period is reasonable.  However, the stratosphere does not support a warm pattern in the East in my opinion.  The stratospheric temperatures at 30 MB are generally running near to slightly above normal, which will continue to support a neutral to negative AO and NAO.  This is the current OBSERVATIONS and not some model solution.  Taken this fact, I think the idea of a neutral or positive NAO for the last week of November and the first week of December is not reasonable.  This is likely a hiccup for the ECMWF and not a trend for the long range, in my opinion.  

In fact, several GFS ensemble guidance strongly supports a negative NAO and a cold pattern in the East and I think this guidance is correct due to the observations at the stratosphere.  I would not be surprised if the ECMWF flips back cold this or the next model run.  

Anyone who is going to be basing the winter on run to run of models will like lose their hair, money, and/or sanity.  I would strongly suggest those individuals to not to do this.

Have a great night!