We have an even bigger dilemma this morning with the
European model. It has pushed the storm even further south and
east, continuing to suggest that the storm will remain so far south of
our area and keeping us so cold, that it actually misses us, while the
American model brings the storm North of us and warms us up so much that we get
rain. Therefore, I am going to continue with my current forecast of
snow for our area, as I continue to believe that the truth lies somewhere
in between these two models, and that would be similar to the ensemble
mean of the American model, and yesterday's ensemble mean of the European
model. The main office for the National Weather Service outside of Washington
D. C. agrees with me this morning, so I am in good company, but wow
is this forecast getting interesting and complicated. Check back
later for my daily forecast. Below is
the forecast discussion from the National Weather Service headquarters. Keep in mind; these are the top forecasters in
the country, so it really shows how difficult this forecast is becoming.
PRELIMINARY EXTENDED FORECAST DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD 305 AM EST FRI NOV 23 2012 VALID 12Z TUE NOV 27 2012 - 12Z FRI NOV 30 2012 GENERAL FLOW PATTERN ==================== A REPETITION OF THE PATTERN SEEN OVER THE PAST FEW WEEKS IS EXPECTED, WITH AN AMPLIFIED TROUGH MOVING INTO THE EASTERN PACIFIC, WITH DOWNSTREAM RIDGING FORMING ACROSS THE WEST AND PLAINS, AND RENEWED TROUGHING ANTICIPATED ACROSS THE NORTHEAST, THOUGH THE RIDGE/TROUGH COUPLET OVER THE LOWER 48 IS EXPECTED TO BE COMPOSED OF BROAD FEATURES OF RELATIVELY LOW AMPLITUDE, WHICH LEADS TO QUICK SHORTWAVE MOVEMENT THROUGH THE COUNTRY. MODEL PREFERENCE ================ MODEL ISSUES ARE SIGNIFICANT THIS PERIOD. THE 00Z ECMWF BECOMES VERY FAST WITH A SHORTWAVE MOVING THROUGH THE PLAINS MONDAY, AND EVEN THOUGH ITS PATTERN ALOFT RESEMBLES THE ENSEMBLE MEAN SOLUTION LATE NEXT WEEK, ITS PRESSURE PATTERN HAS BEEN SO CONTAMINATED BY THIS QUICK-MOVING SHORTWAVE ACROSS THE EAST AND WESTERN ATLANTIC, ITS SOLUTION COULD NOT BE USED. THE 00Z GFS BROKE DOWN THE WESTERN RIDGE WEDNESDAY MORNING BY USING A FORMERLY CLOSED LOW TO DO SO, AND DOES NOT CONVERGE WITH THE REMAINDER OF THE GUIDANCE UNTIL DECEMBER 1ST, SO ITS SOLUTION WAS NOT USED EITHER. THE 00Z CANADIAN SHARPENS THE BASE OF THE SHORTWAVE MOVING THROUGH THE PLAINS EARLY ON, AND SENDS A DEEP CYCLONE ACROSS THE CENTRAL APPALACHIANS INTO THE MID-ATLANTIC STATES WHICH SHOWS LITTLE RESPECT TO THE COOL AIR IN ADVANCE OF THE FEATURE (NO OBVIOUS COLD AIR DAMMING). THE CANADIAN SOLUTION IS ON THE SLOW SIDE OF THE 12Z GLOBAL ENSEMBLE ENVELOPE TO BOOT, AND CONSIDERING THE RELATIVELY LOW AMPLITUDE FLOW, ITS SOLUTION SHOULD BE QUICKER AND POSSIBLY WEAKER HERE, SO ITS SOLUTION WAS NOT BE USED EITHER. PER THE ABOVE, THE PRESSURES USED A 00Z UKMET TEMPLATE THROUGH TUESDAY BEFORE TRANSITIONING TO A 50/50 BLEND OF THE 00Z GEFS/12Z ECMWF ENSEMBLE MEAN SOLUTIONS. THE 00Z UKMET SOLUTION WAS NOT PERFECT EITHER, SHOWING QUICKER PROGRESSION THAN ANTICIPATED BY THE ENSEMBLE LOW CLUSTERING ACROSS THE EAST AND WESTERN ATLANTIC, SO SHIFTED ITS LOW PRESSURE CENTER TOWARDS 12Z GLOBAL ENSEMBLE CLUSTERING TUESDAY AND WEDNESDAY. CONSIDERING THE DETERMINISTIC MODEL SPREAD THIS PERIOD, THE RELATIVELY LOW AMPLITUDE FLOW ACROSS THE LOWER 48 UNITED STATES, AND THE LACK OF AN OVERALL GOOD DETERMINISTIC MODEL CHOICE, CONFIDENCE IS BELOW AVERAGE IN THIS PREFERENCE. ROTH
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