411
FXUS10 KWNH 031850
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
145 PM EST MON FEB 03 2020
VALID FEB 03/1200 UTC THRU FEB 07/0000 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z MODEL EVALUATION WITH FINAL PREFERENCES AND CONFIDENCE
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..EVOLVING FULL LATITUDE TROUGH OVER THE CENTRAL US THROUGH THU
..SURFACE WAVE DEVELOPING OVER THE LOWER MS VALLEY
MOVING INTO
THE INTERIOR MID ATLANTIC LATE
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~~~~~~
PREFERENCE: 12Z NAM/12Z ECMWF/12Z GEFS MEAN/00Z ECWMF ENSEMBLE
MEAN BLEND
CONFIDENCE: AVERAGE
THE 12Z NAM/GFS ARE CLOSE TO THE CONSENSUS WITH THE EVOLVING
POSITIVELY TILTED LONG WAVE TROUGH OVER THE INTERMOUNTAIN WEST
THROUGH THIS EVENING. AFTER THAT TIME, THE 12Z GFS BECOMES FASTER
THAN THE CONSENSUS, AS IT IS NOT QUITE AS DEEP WITH THE EVOLVING
LONG WAVE TROUGH OVER THE ROCKIES INTO CENTRAL AND SOUTHERN
PLAINS. THIS TREND CONTINUES AS THE FULL LATITUDE TROUGH DEVELOPS
OVER THE CENTRAL US BY 07/00Z. THE GFS HAS BEEN CONSISTENTLY
FASTER WITH THIS FEATURE OVER THE PAST SEVERAL MODEL CYCLES.
BY CONTRAST, THE 12Z NAM REMAINS CLOSER TO THE CONSENSUS THROUGH
MUCH OF THE PERIOD AS THE TROUGH EVOLVES. WHILE THE 12Z ECMWF IS
CLOSE TO THE CONSENSUS THROUGH 06/00Z, IT HAS SPED UP ITS MOVEMENT
OF THE LONG WAVE TROUGH FOR DAY 3 (ENDING AT 07/00Z). IT IS NOT AS
FAST AS THE 12Z GFS, BUT IT HAS SPED UP THE TROUGH MOVEMENT DURING
EACH OF THE LAST THREE RUNS. THE TREND FOR A FASTER SOLUTION IS
SEEN IN THE 12Z GEFS MEAN AS WELL. THE FASTER SOLUTION ALSO MAKES
THE 12Z UKMET A PLAUSIBLE SOLUTION, THOUGH IT TOO MAY STILL BE
JUST A BIT FAST. THE 12Z CMC REMAINS THE SLOWEST MEMBER OF THE
GUIDANCE ENVELOPE.
BASED ON THE ABOVE, A BLEND OF THE 12Z NAM/12Z ECMWF/00Z ECMWF
ENSEMBLE MEAN/12Z GEFS MEAN IS PREFERRED. DUE TO THE FLUX IN THE
TIMING OF THE TROUGH AS WELL AS SOME SPREAD IN THE HANDLING OF THE
SURFACE LOW ACROSS THE EAST COAST, FORECAST CONFIDENCE IS JUST
AVERAGE.
...NORTHERN STREAM ENERGY TRACKING FROM BRITISH COLUMBIA TUE INTO
THE NORTHERN PLAINS/GREAT LAKES THU...
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PREFERENCE: NON-12Z GFS BLEND
CONFIDENCE: AVERAGE
SHORT WAVE ENERGY IN THE FAST MID LEVEL FLOW TRACKS FROM THE
CENTRAL BRITISH COLUMBIA COAST 0AT 4/12Z INTO THE NORTHERN PLAINS
BY 05/12Z. DURING THIS TIME FRAME, BOTH THE 12Z NAM/GFS ARE CLOSE
TO THE MODEL CONSENSUS. AFTER 05/12Z, THE 12Z GFS BECOMES MUCH
MORE AMPLIFIED WITH THE TROUGH OVER THE NORTHERN PLAINS/ UPPER MS
VALLEY, CLOSING OFF OVER MN/IA BY 06/12Z. BY CONTRAST, THE 12Z NAM
REMAINS CLOSE TO THE TIGHTLY CLUSTERED CONSENSUS, TAKING THE BULK
OF THE SHORT WAVE ENERGY ACROSS THE NORTHERN PLAINS INTO THE UPPER
GREAT LAKES BY THE END OF THE PERIOD.
THE 12Z ECMWF HAS TRENDED FASTER WITH THE NORTHERN STREAM SHORT
WAVE, WITH ITS TIMING CLOSER TO THE 12Z GFS. HOWEVER, THE 12Z GEFS
MEAN/00Z ECMWF ENSEMBLE MEAN SUPPORT A SOLUTION SLOWER THAN THE
12Z GFS, SO FOR NOW, THE 12Z GFS REMAINS OUT OF THE MODEL
PREFERENCE. HOWEVER, DUE TO THE FASTER 12Z ECMWF SOLUTION,
FORECAST CONFIDENCE HAS DROPPED TO AVERAGE.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
HAYES
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