853
FXUS10 KWNH 070636
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
136 AM EST SAT DEC 07 2019
VALID DEC 07/0000 UTC THRU DEC 10/1200 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: 00Z GFS/12Z ECMWF BLEND
CONFIDENCE: AVERAGE
THE LARGE CLOSED LOW OFF THE WEST COAST WILL CONTINUE TO PROGRESS
EASTWARD AND ALONG WITH STRONGER AMPLIFYING FLOW OUT OF THE
NORTHERN STREAM, WILL EVOLVE INTO A GLOBAL SCALE TROF CENTERED
FROM HUDSON BAY TO NORTHWEST MEXICO BY TUESDAY DOMINATING THE
CONUS. INITIALLY, THE NORTHERN STREAM WILL INJECT SOME SHORTWAVE
ENERGY INTO THE FILLING CLOSED LOW BY TOMORROW AND THE NORTHERN
STREAM WILL CONTINUE TO ACCELERATE AND AMPLIFY THE TROF OVER THE
NORTHERN PLAINS; THIS WHILE THE REMAINS OF THE CLOSED LOW WILL
DESCEND INTO THE SOUTHWEST REMAINING MILDLY POTENT AND DIRECTING
SUBTROPICAL PACIFIC MOISTURE ACROSS THE THE SOUTH INTO THE EASTERN
HALF OF THE US IN ADVANCE OF THE GROWING LARGE SCALE TROF.
GLOBAL GUIDANCE HAS COME INTO MUCH STRONGER AGREEMENT IN THE
PLACEMENT/TIMING OF THE NORTHERN STREAM AND SOUTHERN STREAM
SHORTWAVE FEATURES THROUGH THE FIRST FEW DAYS. THIS WILL LEAD TO
A LARGE/BROAD SURFACE TROF TO DEVELOP FROM SE CO/OK INTO THE GREAT
LAKES BY EARLY MONDAY. AS BOTH SHORTWAVE FEATURES ADVANCE, WITH
THE PACIFIC MOISTURE ENHANCED BY RETURN MOISTURE FROM THE GULF AS
WELL AS RETURN FLOW ALONG THE SOUTHEAST COAST; THE LARGER BROAD
CYCLONE WILL LIFT NORTHEAST INTO THE GREAT LAKES DEEPENING AND
FOCUSING AS IT TRACKS ALONG. THE ENSEMBLE SUITE HAS BEEN
TRENDING TOWARD A CONSENSUS IN THE EVOLUTION OF THIS LARGE SYSTEM
PROVIDING SOME INCREASED CONFIDENCE. HOWEVER, THE FINER/LOWER
SCALE DETAILS STILL SHOW SMALL VARIATIONS THAT LEAD TO
SHIFTS/ADJUSTMENTS OF THE BEST MOISTURE/FORCING AXES. AS SUCH,
THIS LEADS TO A HIGH CONFIDENCE PREFERENCE IN THE PATTERN BUT
AVERAGE TO SLIGHTLY BELOW AVERAGE CONFIDENCE IN THE IMPORTANT
SENSIBLE WEATHER MAKING DETAILS. STILL, THE OPERATIONAL 12Z GFS
AND 00Z ECMWF SOLUTION BLEND APPEARS TO BE IN A TYPICALLY
FAVORABLE RELATION TO THE ENSEMBLES TO EACH OTHER (COMPARED TO
NORMAL VERIFICATION)...THOUGH THE GFS IS SLIGHTLY FASTER AND THE
ECMWF IS SLOWER.
THE 12Z CMC/UKMET, ESPECIALLY IN MASS FIELDS, ARE SLIGHTLY SLOWER
BUT SHOW SIMILAR EVOLUTION TO PROVIDE CONFIDENCE TOWARD A
GFS/ECMWF BLEND EVEN IF NOT PREFERRED IN THE BLEND ITSELF. THE
00Z NAM DID TREND A BIT SLOWER, AND IS NOW ALONG THE FASTER FRINGE
OF THE ENSEMBLE CLUSTERING, AGAIN PROVIDING SOME CONFIDENCE, LIKE
THE UKMET/CMC BUT ON THE OTHER SIDE OF THE ENSEMBLE CLUSTER. THE
00Z NAM ALONG WITH THE 12Z CMC BOTH CONTINUE TO HAVE A COLDER BIAS
IN THE LOWER TROPOSPHERE RELATIVE TO THE OTHER GUIDANCE THAT MAKE
IT SUSPECT AS WELL, PROVIDING ANOTHER REASON TO LIMIT BOTH IN ANY
BLEND. WHILE THE 12Z UKMET IS NOT FAVORED IN MASS FIELDS, THE QPF
AXIS APPEAR TO MATCH/PROVIDE CONFIDENCE TO THE PREFERRED BLEND
(MORE TOWARD EC), BUT REMAINS AN SIGNIFICANT OUTLIER IN A WETTER
SOLUTION ACROSS AZ/NM; STILL ELSEWHERE IT MAY HELP TO SOLIDIFY THE
QPF MAGNITUDE/AXIS OF THE PREFERRED BLEND.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
GALLINA
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