031
FXUS10 KWNH 300637
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
236 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: GENERAL MODEL 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 00Z CMC TRENDED TOWARD THE FASTER
MODEL CONSENSUS LATE IN THE PERIOD AS THE ENERGY ADVANCES
OFFSHORE, AND THUS THE GUIDANCE IS NOW IN VERY GOOD AGREEMENT. A
GENERAL MODEL BLEND WILL NOW BE PREFERRED.
DEEP UPPER TROUGH/CLOSED LOW ACROSS THE INTERMOUNTAIN WEST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z UKMET/ECMWF/GEFS AND 12Z ECENS MEAN
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 MODEL
CONSENSUS AT THIS POINT IS BEST APPROXIMATED BY THE 00Z UKMET AND
00Z ECMWF, WITH REASONABLY GOOD SUPPORT FROM THE 00Z GEFS MEAN AND
YESTERDAY'S 12Z ECENS MEAN. THE 00Z CMC DID TREND GENERALLY TOWARD
THIS CONSENSUS WITH SOME MODEST TIMING DIFFERENCES NOTED WITH THE
LIFTING OF THE CLOSED LOW NORTHWARD INTO SOUTHWEST CANADA. THE 00Z
NAM FOR ITS PART IS ALSO MODESTLY DEEPER THAN THE MODEL CONSENSUS
WITH THE BROADER LARGE SCALE CLOSED LOW EVOLUTION. THE PREFERENCE
WILL BE A BLEND OF THE UKMET/ECMWF SOLUTIONS AND THE LATEST GEFS
MEAN AND ECENS MEAN.
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 00Z GFS/CMC/UKMET
CONFIDENCE: BELOW AVERAGE
A CONVECTIVELY ENHANCED MCV IS FORECAST TO TRACK THROUGH THE
MIDDLE AND UPPER MS VALLEY REGION GOING THROUGH WEDNESDAY. THE 00Z
GFS, 00Z CMC AND 00Z UKMET ALL TAKE ENERGY FARTHER NORTH THROUGH
THE UPPER MIDWEST BY LATE WEDNESDAY, WITH THE 00Z ECMWF SLOWER AND
FARTHER SOUTH OVER EASTERN IA AS THE ENERGY DAMPENS OUT. 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 LIMITED CONFIDENCE, THE PREFERENCE WILL BE TOWARD A
BLEND OF THE MORE PROGRESSIVE AND NORTHERLY TRACKING SOLUTIONS
WHICH STILL HAS A FAIR DEGREE OF ENSEMBLE SUPPORT.
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
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