877
FXUS10 KWNH 111618
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1117 AM EST MON NOV 11 2019
VALID NOV 11/1200 UTC THRU NOV 15/0000 UTC
..SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
..12Z MODEL EVALUATION WITH PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..CONUS THROUGH 84HRS (15.00Z)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND THROUGH 13.12Z
NON-NAM THEREAFTER
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
LARGE SCALE PATTERN APPEARS TO BE DOMINATED BY COLD AIR SURGES OUT
OF THE CANADIAN ARCTIC INTO THE PLAINS. CURRENT RADAR AND GOES
IMAGERY SHOWS A SHORTWAVE MOVING THROUGH THE GREAT LAKES WITH A
TRAILING FRONTAL ZONE ACROSS THE OHIO VALLEY. A VERY STRONG HIGH
PRESSURE/COLD AIR OUTBREAK WILL DRIVE THE COLD FRONT INTO THE
WESTERN GULF WHILE PROVIDING FRONTOGENESIS AND CYCLOGENESIS ACROSS
THE UPPER OHIO VALLEY TONIGHT THROUGH NEW ENGLAND. GUIDANCE HAS
COME INTO SOLID AGREEMENT WITH THIS WAVE TO SUPPORT A GENERAL
MODEL BLEND AT ABOVE AVERAGE CONFIDENCE.
UNCERTAINTY INCREASES (THOUGH NOT SIGNIFICANTLY), WITH THE CLOSED
LOW OVER BAJA CALIFORNIA STARTING TO PROGRESS EAST INTO THE
NORTHERN MEXICO, AS WELL AS, A FAST MOVING SHORTWAVE EMERGING OUT
OF THE NORTHEAST PACIFIC BY EARLY TUESDAY THAT DROPS INTO THE
CENTRAL PLAINS BY WED. HERE, THE GUIDANCE REMAINS FAIRLY WELL
AGREED UPON WITH EVENTUAL, BUT TYPICAL TIMING DIFFERENCES WITH
BOTH SYSTEMS WITH THE GFS/NAM/UKMET FASTER AND THE ECMWF/CMC
SLOWER. THE 12Z NAM IS PARTICULARLY OUT OF SYNC, MOSTLY IN
RETAINING SHALLOW COLD AIR ALONG THE S TX/MEXICO GULF COAST,
REDUCING THE NORTHWARD PRESS OF MOISTURE AS THE CLOSE LOW PRESSES
EAST. THE 12Z RUN IS BETTER THAN PRIOR RUNS BUT STILL NOT
SERVICEABLE IN A PREFERRED BLEND. THE NAM IS ALSO QUITE FAST
WITH THE NORTHERN STREAM SHORTWAVE (LIKELY DUE TO REDUCED
INTERACTION), THIS NEGATIVELY AFFECTS IT ACROSS THE OHIO VALLEY
INTO THE MID-ATLANTIC BY THE END OF THE FORECAST PERIOD. THE 00Z
ECMWF WITH ITS TYPICAL SLOWNESS, ALLOWS FOR GREATER SOUTHWARD
AMPLIFICATION OF THE NORTHERN STREAM SHORTWAVE, THIS ALLOWS FOR
GREATER PHASING/NORTHWARD SURGE OF LOW LEVEL MOISTURE, THIS IS
OPPOSED BY THE FASTER GFS. HOWEVER, THE EVOLUTION/INTERACTION
APPEARS METEOROLOGICALLY SOUND, THAT A BLEND OF THE TWO IN TIMING
WILL SUFFICE (VERY CLOSE TO THE ECENS AND GEFS SOLUTIONS). AS
SUCH, A NON-NAM BLEND IS SUPPORTED WITH BOTH OF THESE WAVES AT
SLIGHTLY ABOVE AVERAGE CONFIDENCE. PLEASE NOTE: THE 00Z CMC IS
AGREED WITH THE SOLUTIONS BUT NOTED THAT THE COLD SURGE THROUGH
THE CENTRAL ROCKIES AND WESTWARD PRESS OF THE FRONTAL ZONE MAY BE
A BIT OVERDONE LATE MON INTO TUES.
AS FOR THE WEST...WITH A FIRM RIDGE ACROSS THE WESTERN HALF OF THE
INTER-MOUNTAIN REGION/WEST COAST, IS SUPPRESSED A BIT ON TUES WITH
THE PASSING NORTHERN STREAM SHORTWAVE, BUT ANOTHER SHORTWAVE RIDGE
BUILDS IN ITS WAKE. WHILE IT IS PROGRESSIVE, IT WILL
DELAY/DEFLECT MOISTURE AND NEXT SHORTWAVE HEIGHT-FALLS FURTHER
NORTH, WITH ONLY A WEAK SUB-TROPICAL STREAM SHORTWAVE MOVING
THROUGH THE AREA ON THURSDAY WITH LITTLE QPF EXPECTED, EXCEPT THE
OLYMPIC RANGE/WESTERN WA. THERE IS SOME SPREAD WITH THE WAVE BUT
NOT TOO BAD, TO SUPPORT A GENERAL MODEL BLEND AT SLIGHTLY ABOVE
AVERAGE CONFIDENCE.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
GALLINA
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page