439
FXUS10 KWNH 080656
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
255 AM EDT MON JUN 08 2020
VALID JUN 08/0000 UTC THRU JUN 11/1200 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION INCLUDING FINAL PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
...POSITIVELY TILTED TROUGH OVER THE INTERMOUNTAIN WEST THAT SPINS
OFF A LOW THAT CROSSES THE CENTRAL ROCKIES MONDAY NIGHT AND LIFTS
OVER THE UPPER MIDWEST WEDNESDAY...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-NAM/GFS BLEND
CONFIDENCE: AVERAGE
A REINFORCING SHORTWAVE MOVING ALONG THE POSITIVELY TILTED TROUGH
OVER THE GREAT BASIN SPINS OFF AS ITS OWN TROUGH THAT CROSSES THE
CO/NM BORDER MONDAY NIGHT AND DEVELOPS INTO A LOW AS IT INTO THE
SOUTH-CENTRAL GREAT PLAINS TUESDAY. THIS LOW TRAILS THE REMNANTS
OF CRISTOBAL THEN THROUGH MIDWEEK AS IT TURNS NORTH AND CROSSES
THE GREAT LAKES WEDNESDAY NIGHT. THERE IS GOOD AGREEMENT ON THIS
PATTERN FOR NON-NCEP MODELS. THE 00Z NAM DEVELOPS THE LOW SOONER
THAN ANY OTHER MODEL AND IS THEREFORE SLOWER WITH THE PROGRESSION
ACROSS THE GREAT PLAINS TUESDAY AND A SLOWER NORTHWARD TRANSITION
ON WEDNESDAY. THE 00Z GFS IS MUCH MORE PROGRESSIVE THAN ANY OTHER
GUIDANCE AND HAS A GREATER INTERACTION OF THE SPUN OFF LOW AND THE
CRISTOBAL REMNANTS MAKING FOR A MUCH DEEPER LOW WITH A FARTHER
WEST TRACK OVER THE UPPER MIDWEST THAN THE REST. THE
ECMWF/UKMET/CMC ALL HAVE A LOW SLOWER THAN THE GFS CROSSING THE
CENTRAL ROCKIES ALLOWING CRISTOBAL TO GET FARTHER AHEAD.
PREFERENCE IS FOR THE 00Z ECMWF/UKMET/CMC WHICH ARE IN GOOD
AGREEMENT.
..CRISTOBAL
~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-GFS BLEND
CONFIDENCE: REFER TO NHC PRODUCTS
NON-GFS MODELS ARE WELL-CLUSTERED THROUGH TUESDAY NIGHT FOR THE
CRISTOBAL REMNANTS TRACK UP THE MISSISSIPPI RIVER THEN TO THE
UPPER MIDWEST. THE 03Z NHC ADVISORY REMAINS ON THE FASTER SIDE OF
THE CONSENSUS SOLUTION OF 00Z GUIDANCE THROUGH TUESDAY NIGHT. ANY
INTERACTION WITH THE LOW APPROACHING FROM THE CENTRAL PLAINS ON
TUESDAY WILL NEED TO BE MONITORED, BUT CONFIDENCE IS GROWING THAT
THE GFS IS TOO AGGRESSIVE WITH THIS INTERACTION.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
...SOUTHERN GULF OF ALASKA LOW STALLING OFF THE BC COAST TUESDAY
NIGHT THROUGH WEDNESDAY...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
THERE IS DECENT AGREEMENT ON POSITION AND INTENSITY OF THE LOW
STALLING OFF THE BC COAST (NEAR THE BORDER WITH AK) THROUGH DAY 2
WHICH IS WHEN MOIST ONSHORE FLOW PROVIDES PRECIP TO THE PAC NW.
GUIDANCE DIVERGES IN PLACEMENT OF THE LOW (THAT REMAINS OFFSHORE)
WEDNESDAY NIGHT, BUT LITTLE IF ANY QPF IS EXPECTED OVER THE
NORTHWEST CONUS ON DAY 3, SO FOR PRACTICAL PURPOSES A GENERAL
MODEL BLEND WORKS FOR THIS FEATURE WHICH HAS THE MOST IMPACT
THROUGH DAY 2.
JACKSON
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