997
FXUS10 KWNH 190640
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
139 AM EST TUE NOV 19 2019
VALID NOV 19/0000 UTC THRU NOV 22/1200 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION WITH PREFERENCES AND FORECAST CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..OVERALL PATTERN ACROSS THE CONUS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND, LESS WEIGHT ON 00Z GFS
CONFIDENCE: AVERAGE
---06Z UPDATE---
NO CHANGE TO THE PRELIMINARY PREFERENCE. THE 00Z ECMWF, CMC AND
UKMET REMAINED RELATIVELY CONSISTENT IN THEIR DEPICTION OF MASS
FIELDS.
---PREVIOUS DISCUSSION---
MODELS CONTINUE TO SHOW FAIRLY GOOD AGREEMENT ON THE SYNOPTIC
PATTERN AND THE PLACEMENT OF LARGE SCALE REGIONS OF QPF. THERE ARE
TWO AREAS WITH NOTABLY MORE ENSEMBLE SPREAD: (1) TIMING OF THE
TROUGH EJECTING FROM THE SOUTHWEST, AND (2) SHORTWAVE DIGGING INTO
THE UPPER MIDWEST AND ASSOCIATED INTERACTIONS WITH THE
AFOREMENTIONED TROUGH. DESPITE SOME DIFFERENCES, THERE AREN'T MANY
SYSTEMATIC BIASES THAT WOULD FAVOR ONE MODEL OVER ANOTHER AND THUS
A GENERAL MODEL BLEND IS PREFERRED.
LESS WEIGHT IS PLACED ON THE 00Z GFS, WHICH HAS A DIFFERENT
DEPICTION OF THE EVOLUTION OF THE SOUTHWEST TROUGH COMPARED TO THE
REMAINING GLOBAL MODELS. IT LIFTS THE CLOSED LOW FURTHER NORTH
INTO UTAH BY 21.12Z, WHILE MOST OTHER MODELS ARE CENTERED CLOSER
TO LAS. ADDITIONALLY, IT CONTINUES TO SPREAD HEIGHT FALLS OUT INTO
THE PLAINS SOONER, AND OPENS THE CLOSED LOW UP INTO A TROUGH
FASTER. THESE DIFFERENCES DO HAVE AN EFFECT ON QPF, WITH
PRECIPITATION DIMINISHING MORE QUICKLY FROM WEST TO EAST.
THEREFORE, THE PREFERENCE IS FOR A MULTI-MODEL BLEND THAT
GRADUALLY PLACES LESS EMPHASIS ON THE GFS, PARTICULARLY AFTER
WEDNESDAY MORNING (20.18Z).
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
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