"WHAT HAVE YOU DONE FOR ME LATELY ?"
That's probably accurate for today's headline since there has not been a "new" post since Saturday night. Sometime earlier today, you probably happened across the Weather Channel or your local NWS forecast and discovered that the "Rain/Snow" with a high of 38 for Baltimore disappeared. In it's place is now "Chance of Showers with high of 53." For our northern clients, please pardon the emphasis on the southern areas, as I am using it to illustrate a point.
I CAN FIND NO MODEL SUPPORT for this forecast. I saw this and thought, "Hmmm, GFS must have done a real role reversal or something for the NWS to go totally the other direction." So I checked the GFS, and the European, and the NAM, and the DGEX and the UKMET and NONE of them depict a scenario which would lead to showers and 50's. In fact if you check local NWS forecasts for areas very close to Baltimore, like Cecil County MD or across the Chesapeake, there is barely a mention of rain... mostly cloudy and 40's.
SO WHAT'S GOING ON? The models are having a hard time resoloving the imbalances in the system caused by the Polar Vortex, the building southern stream in conjunction with the Atlantic Ridge, as well as the persistent Canadian High that has and will dominate Northeast weather through the weekend. What's happened is that the computer sees a zonal west-east flow and thinks "Hey, warmth is coming... let's warm things up." The Philadelphia office put it best by saying in their forecast discussion "Most long range models seem to be in disagreement over the details."
IS OUR BIG STORM HISTORY BEFORE IT WRITTEN? No, the window for a final snow event in the Mid-Atlantic is still open for Saturday-Sunday-Monday. I can say that beyond that the window appears it will close for good on this winter. Andy, our designated skeptic in York County, PA maintains that no more than 4 inches of snow will fall at BWI the remainder of the season, and he may end up to be the most accurate on that forecast. If the skeptics win and I lose on the Final Kahuna, you can be sure I'll be the first to tell you why.
AND THE WEEKEND? I believe we (the Northeast) will see cooler temperatures than are advertised, and that the storm coming east out of the Lakes by then is going to get squeezed between the southern stream/ridge and the northern Highs. This will force a piece of energy to zip out towards the Mid-Atlantic and travel through Maryland with potential for development once it reaches the coast. Now storms from the west don't bring extra rest, so snow falling out of this system will not be enough to disrupt school on Monday, especially if it is on the order of 4 inches or less as predicted by Andy. New England should continue to see below normal conditions and tranquil weather through Sunday. The final forecast outlining the weekend storm and any potential for snow will be posted Thursday.
WHERE'S THE 'TRAIL' WE ARE BLAZING? DID WE LOSE IT? Still trailblazing, just a different trail...this time tracking if the weekend storm will be our Final Kahuna or not.