THE BEST OF WINTER IS YET TO COME
Punxstawney Phil, the ultimate weather prognosticator will, on February 2, thanks to abundant sunshine, see his shadow...and predict six more weeks of winter. It probably won't feel like winter where you live, but have faith. The best of winter is yet to come, and I will present convincing evidence in the next 2 days to demonstrate why I am confident in this forecast.
I am preparing a simplified version of the February Forecast that gets right down to business, and will hopefully resolve some of the burning issues you may have in regards to the progress of winter thus far in the Eastern United States. This post will follow the revisions made to Tuesday morning's post. The graphics below are an example of the difficulty some computer models and forecasters have had in identifying certain types of storm events within the overall pattern. It has been a disappointing winter for some, but remember that winter is only half completed.
SUMMARY OF THIS WEEK'S WEATHER...updated
A slow moving storm system continues to move across Texas and the southeast over the next 2 days, reaching the Carolinas by Thursday night. At the same time, the storm which exited the Mid-Atlantic Coast on Sunday has redeveloped and expanded considerably in size. By Thursday, moisture from this storm will begin to northwestward toward the New England Coast. The Gulf system will spread interior mountain snows in the western Carolinas, and extreme southwestern Virginia, and then largely move out to sea. Also by Thursday night, moisture from these two systems will interact and produce a mix of precipitation from Virginia to Southern and Southeastern New England. For metropolitan areas from Boston south to Washington, including Philadelphia and Baltimore, the most realistic scenario is that any precipitation would start as some wet snow Thursday night, and then changeover to rain by Friday morning. The absence of a large High pressure system is likely to prevent this system from developing into a large snowstorm, thus any accumulations will be light. Once the storm departs Saturday, a high pressure ridge re-established control over most of the East half of the country, providing a pleasant weather for Super Bowl parties on Sunday the 6th.
BASIC STORM FORECAST...updated
Scroll down to the geographic area that pertains to you.
Storm 2 : Eastern/Southern New England, Thursday-Friday. This system is really just an older version of Storm 1 that just exited the coast Sunday. Several computer models including the GFS, show a warm sector of this retrograding toward New England by Thursday. Both the Boston and New York NWS offices have kept a mention of snow in their forecasts, because with such a large reservoir of entrained moisture, you cannot rule out even the remotest possibility that some will reach the coast.
I agree that the absence of cold air or a large high pressure system will prevent any heavy accumulation of snow anywhere with this storm. However, due to the storm's evening arrival time, precip is likely to start as wet snow, then change to freezing rain, and finally all rain.
I am maintaining my call for accumulations in Southeast New England to range generally 2-4" because I think everyone else is going to end up retrograding THEIR forecasts back to what they originally said. The NAO is clearly sending a signal that significant upper level atmospheric blocking in the Northern Atlantic will cause Storm 2 to send an easterly flow of moisture much farther west than the computer models are indicating. There will also be very gusty winds and heavy wave action as you'll have a strong northerly fetch across the Gulf of Maine.
Storm 3A : Gulf/Southeast/Mid-Atlantic, Tuesday-Thursday. This system is crossing Texas as Tuesday morning, and cold air on the backside will deliver up to 6" of wet snow in the Texas panhandle Tuesday night. Enough air may filter in to turn rain to snow in Dallas by tonight. By Wednesday night, the system has moved to the TN/GA border. The Raleigh, NC Forecast Office wins the big prize for being first out of the gates with a Special Weather Statement on this system on Monday and has stuck to their guns on this. The latest QPF (Quantitative Precipitation Forecast) shows considerable moisture as you would expect from a Gulf system. The current NAM (North American Model) shows the rain/snow line with this system by Wednesday running from eastern Tennessee to southern Virginia, so it seems plausible those areas would have an early morning snow and rain mix Thursday night. The heaviest snows will confined to the mountains of North Carolina along a line from Winston-Salem to Charlotte on west.
While some computer models show this system just heading out to sea, in the face of a strongly negative NAO, I think what we are starting to see is moisture from Storm 3A becoming entrained in the southwest quadrant of inflow for Storm 2. We could eventually see a lot of moisture from Storm 3A simply turn Storm 2 into a real monster, and back further west, throwing all forecasts out of whack for the Thursday-Saturday time frame.
Storm 3B : Mid Atlantic, Friday. This system will be a redevelopment of Storm 3A, and form sometime Thursday night near the Virginia Capes. At the same time, we have moisture streaming northeastward ahead of Storm 3A. The formation of Storm 3B will absorb moisture from 3A, helping to intensify it under the trough. Now this system has TWO sources, one is warm moist air from the southeast, the other is moderated moist air from the northeast. However, the lack of a fresh supply of cold air will prevent any heavy accumulations of snow. The most likely scenario is a wet snow/rain mix starting Thursday night in central Virginia, and early Friday morning for most of Maryland east of the mountains. As this system moves northeast, it will draw in moist air from the ocean, and change the snow over to rain during Friday. The metro areas of DC, Baltimore and even Philly may see a couple quick inches of wet snow early Friday morning before a changeover to rain.
WHAT ABOUT SCHOOL?
If this scenario pans out, schools in western North Carolina will have to close for parts of Thursday and Friday. The DC and Baltimore metro region will face a tough call Friday morning. Does a 2 hour delay allow enough time for a changeover to rain? Or if the storm begins to develop off the coast, will it pull in enough cold air to keep the precip all snow for the critical time period of 5AM to 7AM Friday morning? Southwestern Virginia is in line for more accumulation that the previous storm, as is the North Carolina mountains.
WILL THIS NEW STORM THEN GO NORTH, SOUTH OR EAST?
Very difficult to determine where Storm 3B goes from this point. Obviously it will move northeast eventually, but if it lingers along the coast for a longer period than we think, the nice weather on Friday or Saturday is in jeopardy.
THE SIMPLIFIED FEBRUARY FORECAST... INCLUDING EVIDENCE FOR BIG KAHUNAS 1 AND 2,
IS THE TOPIC OF WEDNESDAY MORNING'S 6 AM BREAKFAST POST.