The image below is from the latest Global Ensemble Forecast System (GEFS) model showing a major upper-level pattern change developing across the northern hemisphere. You’ve heard me refer to the “North Atlantic Oscillation” (NAO), and the “Arctic Oscillation” (AO), both of which dictate the behavior of the upper level westerlies (the jet stream) across the middle and northern latitudes.
In the image above, note the upper-level ridging (bright red shades) fade across the northeastern United States before building in across the North Atlantic (Greenland and northeastern Canada). This pattern shift is indicative of the “North Atlantic Oscillation” shifting from its positive to negative phase. When the NAO tanks (drops rapidly), look out on the east coast for Nor’easters! When the AO dips, arctic air will likely be making its way southward out of Canada into the United States.
The GEPS (Canadian Ensemble Prediction System) model seen in the image above agrees with the GFS.
The European EPS (Ensemble Prediction System) is also in general agreement with this massive pattern change.
So this means that we can all count on 20″ of snow crippling DC and shutting down our region for two weeks, right? Not so fast. Everything would have to come together perfectly (especially the exact track) for DC to get buried by a heavy, wet, snowfall.
The good news for you snow-lovers (myself included): Several of the ensemble members (there are a total of 50) are starting to show the potential for some hefty snowfall accumulations around here over the next 15 days. Will the trend continue?
My $0.02 cents … it currently appears that the first opportunity for “fun” between Washington and Boston would be next Friday through Sunday (a week from now) followed by another and more amusing potential event (more so for the Washington Region) between March 5 and 10th.
Until then my friends, we can hope and dream. For those of you snow-haters, move to Florida… we have had one of the driest, dreariest, winters I can remember with pathetic little snows (under 2″). There are states in this Union that are snow-less with 2 seasons (“Hell” and “Fall”), with sub-par schools, zero culture and about 6 months where you can fry at 98 degrees with heat indexes of 110 and dew points in the 70s. The Deep South is calling your name, and they have very hungry gators down there too that are just waiting for you to dip your feet in the nearest swamp (which is likely filled with flesh-eating bacteria). Long Live the Yankee Northeast Megalopolis!