438
FXUS10 KWNH 250638
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
237 AM EDT THU JUN 25 2020
VALID JUN 25/0000 UTC THRU JUN 28/1200 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION INCLUDING PREFERENCES AND FORECAST CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CLOSED LOW OVER ONTARIO/QUEBEC
TROUGH CROSSING THE EASTERN U.S.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 00Z GFS/00Z CMC/00Z ECMWF BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
THE 00Z NAM/GFS ARE CLOSE TO THE CONSENSUS WITH THE MID LEVEL
CLOSED LOW AS IT TRACKS FROM EASTERN ONTARIO INTO WESTERN QUEBEC,
BEFORE SLOWING DOWN AND SPINNING OVER CENTRAL QUEBEC THROUGH
28/12Z. HOWEVER, THE 00Z NAM APPEAR TO BE TOO FAST WITH ITS
SURFACE LOW CROSSING NORTHERN ME (AS IT THE 00Z UKMET, WHICH SPED
UP WITH THE SURFACE AND MID LEVEL SYSTEMS HERE), WHILE THE 00Z
GFS/00Z ECMWF SHOW BETTER CLUSTERING WITH THE 12Z ECMWF ENSEMBLE
MEAN (AND THE FRONT THAT MOVES ACROSS THE EAST COAST LATE IN THE
PERIOD). THE FASTER 00Z UKMET AND 00Z NAM SOLUTIONS WERE DROPPED
FROM THE CONSENSUS, LEAVING A FAIRLY TIGHT CLUSTER COMPRISED OF
THE 00Z GFS/00Z CMC/00Z ECMWF). THE FORECAST CONFIDENCE REMAINS
SLIGHTLY ABOVE AVERAGE, AS THE ABOVEMENTIONED CLUSTER HAS THE
SUPPORT OF ENSEMBLE MEANS.
SHORT WAVE CROSSING THE PACIFIC NORTHWEST AND PLAINS/MIDWEST
LONG WAVE TROUGH DIGGING INTO THE SOUTHWEST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
FOR THE SHORT WAVE ENERGY TRACKING FROM THE PACIFIC NORTHWEST INTO
THE NORTHERN PLAINS, THE 00Z NAM/GFS ARE CLOSE TO THE CONSENSUS
TAKING IT ACROSS SD INTO IA/IL, AS WELL AS THE SURFACE LOW MOVING
ACROSS ONTARIO. THESE SOLUTIONS ARE CLOSE TO THEIR ENSEMBLE MEANS,
AS WELL AS THE 12Z ECMWF ENSEMBLE MEAN. GIVEN THE TIGHT
CLUSTERING, A GENERAL MODEL BLEND IS PREFERRED.
FOR THE POSITIVELY TILTED LONG WAVE TROUGH CROSSING CA AFTER
26/00Z, THE 00Z CMC SLOWED ITS TIMING WITH THE MID LEVEL SYSTEM,
AND NOW IS PART OF THE TIGHTLY CLUSTERED SOLUTION AS THE MID LEVEL
SYSTEM REACHES THE SOUTHWEST STATES BY 28/12Z.
STRONG SHORTWAVE TROUGH OVER THE PACIFIC NORTHWEST THIS WEEKEND
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
THE 00Z NAM/GFS ARE CLOSE TO THE CONSENSUS TAKING SHORT WAVE
ENERGY FROM THE GULF OF AK ACROSS THE BRITISH COLUMBIA COAST AFTER
27/00Z. ADDITIONAL MID LEVEL ENERGY DROPPING INTO THE SHORT WAVE
POSITION OVER BRITISH COLUMBIA/ALBERTA CAUSES THE SYSTEM TO CLOSED
OFF OVER THE PACIFIC NORTHWEST TOWARD THE END OF THE PERIOD. BY
THAT TIME, THE 00Z NAM/GFS ARE A BIT FASTER THAN THE CONSENSUS,
BUT THERE IS MORE SPREAD IN GENERAL THROUGHOUT THE MODEL
SOLUTIONS. HOWEVER, THIS CLUSTER IS NOT FAR FROM THE 12Z ECMWF
ENSEMBLE MEAN/00Z GEFS MEAN, SO THE SLIGHTLY FASTER SOLUTIONS ARE
NOT TOO FAST NOT TO INCLUDE IN A GENERAL MODEL BLEND. GIVEN THE
SPREAD, THOUGH, FORECAST CONFIDENCE IS AVERAGE.
LOWER MS VALLEY AND GULF COAST STATES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
THOUGH THE 00Z GFS IS A BIT STRONGER WITH THE SHORT WAVE ENERGY IN
THE MID LEVEL FLOW ACROSS THE REGION, IT DOES HAVE SOME SUPPORT
FROM THE 00Z UKMET. OVERALL, THERE IS FAIRLY GOOD CLUSTERING IN
THE MID LEVEL FLOW (OUTSIDE OF WEAK IMPULSES IN THE MID LEVEL FLOW
THAT REGIONAL/GLOBAL MODELS CANNOT YET RESOLVE) AS HEIGHTS FALL
ACROSS THE LOWER MS VALLEY AND GULF COAST STATES. BASED ON THIS, A
GENERAL MODEL BLEND IS PREFERRED, WITH SLIGHTLY ABOVE AVERAGE
CONFIDENCE.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
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