(Today's weather conditions are referred to in later paragraphs..Facebookers ( click read on). Want to refer to the 'cold' stuff first as a prelim in these first paragraphs.
Friday Through Friday Night... the ECM/UKM/NAM forecast models are slightly slower with the timing of the upcoming MAJOR cold frontal passage---diverging from the GFS. But I'm In agreement with all (with a minor timing differentation), but what it all amounts to in the long run is that rapid Southeastward acceleration of the boundary (front) during the day on New Years is a given as a strong coastal low pressure system literally 'bombs out' over the Western Atlantic off New Jersey ....another guarantee (have fun..... J "T" C)!! . Any shower activity that materializes (which is becoming lesser with time during the mid-night to late afternoon hours of the New Year Day) will rapidly translate southeast and out of the picture. Cold Air Advection will RAPIDLY ensue behind the cold fronts passage.
In other words...it's going to get cold FAST. We can expect a good 15 degree temperature drop within the first 2 hours of cold frontal passage..which at this time appears to be around the 10am-2pm time frame. But if the lagging trend continues as portrayed by previous, consecutive model runs since Monday..it might be more like a 2-5pm time frame (but I really don't expect that). It won't take a "weather man to know"..at the first hints of a stronger wind, and much cooler air swipping away your "good hair day"..You'll know.."He's Baaaack!".
Regardless of either and/or/ but ..., by 6pm in the pre-sunset hours we're going to know that winter has arrived with gnashing teeth accompanied by WNW to NW winds gusting to about 24 mph. NO FUN! Boo..hiss...and Beyond Comprehension. HaHa..you'd think we're in for a blizzard!!
And old man winter is here to stay too...rain chances though, after late Friday, will be nil for a week at least...as will warm air. The upper level polar vortex will rotate around the great NE U.S. *just like it did all summer by the way: and eject sporadic pockets of upper level energy down its base and across the U.S. Deep South East for a sequential period of days providing cold air "reinforcements"..(in come the troops)..and that coupled with a strong Southern Branch Jet "Streaming" just to the south of us or over us...will not only generate much below normal temperatures..but periods of mid and upper level cloud cover as accompaniment. Sometimes I just hate El Nino winters.
For now..expect today to be very comfortable with a high in the mid-70s and a land breeze (our saving grace from any wind that could come off the ocean's 67, if not cooler, temperature). But clouds will be on the increase as a gift from the mid and upper level winds that will propogate clouds in ahead of the developing situation (note that I didn't refer to 'it' as a storm)...although some cloud breaks can't be disregarded as a genuine possibility.
Nothing becomes to exceptionally affirmative (forecast wise) until New Year's Day Break whence we should be affirmatively be consumed by clouds and the approaching cold frontal boundary. Rain chances in the models I believe are way over done..some folks might not get rain at all..others might get totals up to a quarter inch.
The major point to made for this post is..prepare for a LONG DURATION VERY COOL TO COLD EVENT (contingent upon what considers cold of course). If you like a high temperature around 58 degrees and a low around 44 then jump with glee. Break out the clothing reserved for such occasions..why not..it can be fun and stylish :-)
It will be colder on some upcoming mornings beyond the scope of this post..especially away from the coast..as there will be some flunctuations based on the timing of particulars that will materialize at free will as the vortex gives birth to sub-vortexes that will rotate around the base of the trough (hovering over the southeast United States..including Florida) causing it to sporadically dig a tad further south and thus allow the thickness values between 1000mb-500mb layer to decrease, ...AKA colder air to penetrate.. anything of significant, forecastable influence astray from what has already been written will be alluded to in later posts.
Thanks for your help National Weather Service, Melbourne. You pulled the words right out of my gut in your forecast discussions (the REAL SOURCE for our local weather)..so I could put them to virtual paper! You guyz rock.