166
FXUS10 KWNH 300418
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1217 AM EDT TUE JUN 30 2020
VALID JUN 30/0000 UTC THRU JUL 03/1200 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION INCLUDING PREFERENCES AND FORECAST CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CLOSED LOW ANCHORED OVER NEW ENGLAND
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-CMC BLEND
CONFIDENCE: ABOVE AVERAGE
THE LATEST MODEL GUIDANCE MAINTAINS THE UPPER LOW OVER THE
INTERIOR OF NEW ENGLAND GOING THROUGH EARLY THURSDAY. THEREAFTER,
THE ENERGY IS FORECAST TO SHIFT OFF THE EAST-SOUTHEAST AND
OFFSHORE OF THE EAST COAST. THE GUIDANCE IS RATHER WELL CLUSTERED
WITH THIS EVOLUTION THROUGH THE PERIOD, BUT THE 12Z CMC DOES END
UP BEING SLOWER TO ADVANCE THE HEIGHT FALLS OFFSHORE BY EARLY
FRIDAY. A NON-CMC BLEND WILL BE PREFERRED WITH THIS SYSTEM FOR THE
TIME BEING.
DEEP UPPER TROUGH/CLOSED LOW ACROSS THE INTERMOUNTAIN WEST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z GFS/12Z UKMET/12Z ECMWF
CONFIDENCE: AVERAGE
THE STRONG UPPER-LEVEL LOW OVER THE INTERMOUNTAIN WEST WILL LIFT
NORTHEAST OVER THE NORTHERN ROCKIES THROUGH TUESDAY BEFORE MERGING
WITH ANOTHER SHORTWAVE TROUGH AND ASSOCIATED CLOSE LOW APPROACHING
SOUTHWEST CANADA. THE CONSOLIDATION OF THIS ENERGY WILL RESULT IN
A LARGE CLOSED LOW OVER THE PACIFIC NORTHWEST TO NORTHERN ROCKIES
GOING THROUGH WEDNESDAY. BY THURSDAY, YET ANOTHER COMPACT
SHORTWAVE AND ASSOCIATED CLOSED LOW WILL DROP SOUTH DOWN THE COAST
OF BRITISH COLUMBIA AND INTO THE PACIFIC NORTHWEST WHICH WILL HELP
TO DRIVE THE LARGER CLOSED LOW UP INTO SOUTHWEST CANADA. THE 12Z
CMC IS OVERALL AGAIN THE MOST OUT OF PHASE COMPARED TO THE
REMAINING GUIDANCE AS IT SUGGESTS A STRONGER CLOSED LOW EJECTING
NORTH OUT OF THE NORTHERN ROCKIES AND INTO SOUTHWEST CANADA. IT
ALSO IS THE MOST PROGRESSIVE WITH THE ENERGY DROPPING DOWN THE
COAST OF BRITISH COLUMBIA AND THE PACIFIC NORTHWEST. THE 00Z NAM
FOR ITS PART IS ALSO MODESTLY DEEPER THAN THE MODEL CONSENSUS WITH
THE BROADER LARGE SCALE CLOSED LOW EVOLUTION. THE BETTER MODEL
CLUSTERING RESIDES AGAIN WITH THE 00Z GFS, 12Z UKMET AND 12Z
ECMWF, SO A BLEND OF THESE SOLUTIONS WILL BE PREFERRED.
MCV/WEAK MID-LEVEL LOW OVER NORTHERN MN
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE MCV AND ASSOCIATED WEAK MID-LEVEL CLOSED LOW OVER NORTHERN MN
THIS EVENING WILL LIFT NORTH THROUGH WESTERN ONTARIO OVER THE NEXT
24 HOURS. MODEL SPREAD IS MINIMAL WITH THIS EVOLUTION AND SO A
GENERAL MODEL BLEND WILL AGAIN BE PREFERRED WITH THIS FEATURE.
MCV CROSSING THE MIDDLE AND UPPER MS VALLEY TUESDAY/WEDNESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 12Z CMC/UKMET/ECMWF
CONFIDENCE: SLIGHTLY BELOW AVERAGE
A CONVECTIVELY ENHANCED MCV IS FORECAST TO TRACK THROUGH THE
MIDDLE AND UPPER MS VALLEY REGION GOING THROUGH WEDNESDAY. ALL OF
THE GLOBAL MODELS AGREE ON THIS SCENARIO WITH THE 12Z NON-NCEP
MODELS WELL CLUSTERED ON THEIR TIMING OF THE ENERGY AS IT CROSSES
THE UPPER MIDWEST AND EVENTUALLY ARRIVES ACROSS SOUTHERN CANADA.
THE 00Z GFS IS A TAD SLOWER THAN THE NON-NCEP GUIDANCE. THE 00Z
NAM THOUGH STALLS THE ENERGY OUT OVER WESTERN IL ON TUESDAY AND
THEN DROPS THE ENERGY SOUTHEASTWARD THROUGH THE MID SOUTH BY
THURSDAY. WITH SOMEWHAT LIMITED CONFIDENCE, THE PREFERENCE WILL BE
TOWARD A BLEND OF THE MORE PROGRESSIVE AND NORTHERLY TRACKING
NON-NCEP SUITE OF GUIDANCE WHICH IS FAVORED BY THE BULK OF THE
LATEST ENSEMBLE GUIDANCE.
MID-LEVEL CLOSED LOW OVER THE GULF COAST BY FRIDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-NAM BLEND
CONFIDENCE: ABOVE AVERAGE
A MID-LEVEL TROUGH AND DEVELOPING CLOSED LOW IS EXPECTED TO FORM
OVER THE GULF COAST STATES BY FRIDAY AS WEAK SHORTWAVE ENERGY
DROPS DOWN THROUGH THE MID SOUTH. THE 00Z NAM IS A BIT STRONGER
THAN THE GLOBAL MODELS AS IT TAKES THE AFOREMENTIONED MCV OVER
WESTERN IL DOWN TO THE SOUTHEAST WHICH RESULTS IN A MORE AMPLIFIED
TROUGH OVER THE GULF COAST REGION. A NON-NAM BLEND WILL BE
PREFERRED FOR THE TIME BEING SINCE THE GLOBAL MODELS ARE GENERALLY
WELL CLUSTERED.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
ORRISON
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page