Rockin' Weatherwise Into The New Year

If you believe the Physical Science Division (PSD) reforcast model or the Euro, it appears that the 1st couple of weeks into January could get exciting around these parts if you're a lover of winter weather.  However, before I address those thoughts, lets look at what is coming at PA for the next 24-48 hrs.  Below is a current water vapor image of the US.  The blues are very wet regions of deep moisture in the mid and upper levels at the atmosphere.  Simply put, these pockets of atmosphere support moderate to heavy rainfall.  That blob is advecting directly towards PA.  Therefore expect a fairly healthy dose of liquid sunshine Tuesday into early Wednesday morning.

Here is what the NAM says in terms of amounts of rainfall for the period ending Wednesday midday.

Once the storm passes through by Wednesday at sunrise, cold and blustery conditions will prevail for Wednesday with daytime maxes struggling to get out of the 30s.  With winds gusting to 30+mph, it will feel like the coldest day of the week.  Take a look at the midday winds.

But what I want to really alert y'all to is the likelihood of some fun 'n' games beginning with the changing of the calendar.  The Euro has one deep trough digging deeply into the eastern US this weekend with a reinforcing shot of cold quickly following.  I am showing the deepest trough in the graphic below.  This is the operational run of the ECMWF forecast for Monday.

And here are the Euro ensembles for the midweek period next week...

And even the highly regarded PSD reforecast model that has been performing very well since its inception within the past several months!  That is most decidedly placing a deep trough here in the eastern part of the US with a ridge off the west coast.  This type of pattern should allow for some winter storminess here in the eastern part of the states and the northeast. 

Maybe January will have some winter wx to offer as being suggested by both the GFS reforecast project and the Euro Center's ensembles.  There are caveat, however, the primary one being no negative NAO or negative AO.  Thus any cold shot should be transient unless blocking upstream develops over the high latitudes near Greenland.  Trust me, there is plenty of cold Arctic air available in NW O Canada and AK.  Look at this article from Reuters...

Look at that cold over AK and NW O Canada.  Compare that to the anomalous warmth over the Mississippi Valley as shown by the GFS operational.  That will change somewhat as next week progresses with that digging trough that will usher in much colder air from the polar region.

OK...so we are watching for a pattern change...and that will not occur until the New Year.  Until then, enjoy Dan Fogelberg's version of Same Old Lang Syne from 1980.  This song has always been one of my favorite ballads about the adventures of life.  I hope you enjoy it as well...

Smitty

AA:  Looking to a pattern change to colder and stormier wx for the 1st couple of weeks in January.  A rainy Tuesday pm and a windy & cold Wednesday.