061
FXUS10 KWNH 280654
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
253 AM EDT SUN JUN 28 2020
VALID JUN 28/0000 UTC THRU JUL 01/1200 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION INCLUDING PREFERENCES AND FORECAST CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CLOSED LOW OVER QUEBEC AND ACCOMPANYING SHORTWAVES
TROUGH IMPACTING THE NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-NAM BLEND
CONFIDENCE: ABOVE AVERAGE
AN UPPER-LEVEL LOW INITIALLY OVER QUEBEC WILL SUSTAIN A BROAD
UPPER-LEVEL TROUGH CENTERED OVER THE EAST COAST THROUGH SUNDAY.
THE MODELS ARE IN GOOD AGREEMENT ON THEN GRADUALLY BRINGING THIS
UPPER LOW SOUTHWARD EARLY NEXT WEEK, WITH THE GUIDANCE FOCUSING IT
OVER THE INTERIOR OF NEW ENGLAND MONDAY AND TUESDAY. THE 00Z NAM
BRINGS THE UPPER LOW FARTHEST SOUTH, WITH THE NON-NCEP MODELS
GENERALLY CLUSTERED A LITTLE FARTHER NORTH, AND THE 00Z GFS IN
BETWEEN THESE CAMPS. OVERALL, THE NAM IS THE BIGGER OUTLIER SO A
NON-NAM BLEND WILL BE PREFERRED.
MCV CURRENTLY OVER SOUTHERN IL
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-NAM BLEND
CONFIDENCE: AVERAGE
THE MODELS TAKE THE MCV CURRENTLY OVER SOUTHERN IL OFF TO THE EAST
ON SUNDAY WITH THE ENERGY GRADUALLY SHEARING OUT AS IT ARRIVES
ACROSS THE CENTRAL APPALACHIANS. THE 00Z NAM IS THE STRONGEST
SOLUTION WITH THIS SYSTEM, AS THE 00Z HREF GUIDANCE AND THE GLOBAL
MODELS ALL AGREE AND CLUSTER ON A SOMEWHAT FLATTER MCV THAT SHEARS
OUT BY SUNDAY EVENING. A NON-NAM BLEND WILL BE PREFERRED.
DEEP UPPER TROUGH/CLOSED LOW ACROSS THE INTERMOUNTAIN WEST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z GFS/UKMET/ECMWF
CONFIDENCE: AVERAGE
A DEEP UPPER TROUGH AND ASSOCIATED CLOSED LOW IS FORECAST TO
AMPLIFY ACROSS THE NORTHERN ROCKIES AND INTERMOUNTAIN WEST OVER
THE NEXT COUPLE OF DAYS AS AN UPPER-LEVEL RIDGE BUILDS ACROSS THE
GULF OF ALASKA AND ALSO ACROSS THE MIDWEST AND GREAT LAKES REGION.
THIS WILL YIELD A QUASI OMEGA-BLOCK PATTERN ACROSS THE CENTRAL AND
WESTERN U.S. THE 00Z NAM AGAIN TENDS TO BE ON THE STRONG SIDE WITH
THE HEIGHT FALL EVOLUTION ACROSS THE WEST AS IT HAS A STRONGER
UPPER LOW IMPACTING THE NORTHERN ROCKIES MONDAY AND TUESDAY. THE
00Z CMC ONCE AGAIN TENDS TO BE SLOWER WITH THE TROUGH EVOLUTION
AND LAGS THE REMAINING MODEL SUITE AS THE ENERGY PIVOTS THROUGH
THE INTERMOUNTAIN REGION. THE 00Z GFS, 00Z UKMET AND 00Z ECMWF
HAVE SOME MODEST TIMING/DEPTH DIFFERENCES BUT OVERALL ARE WELL
CLUSTERED AND REPRESENT THE MODEL CONSENSUS. THIS CLUSTER ALSO HAS
GENERALLY GOOD SUPPORT FROM YESTERDAY'S 12Z ECENS MEAN AND 18Z
GEFS MEAN. HOWEVER, IT WAS NOTICED THAT THE 00Z GEFS CAME IN
SLOWER AND ACTUALLY DOES TEND TO SUPPORT THE CMC. FOR NOW, THE
PREFERENCE WILL STILL BE TOWARD A BLEND OF THE GFS, UKMET AND
ECMWF.
SHORTWAVE ENERGY LIFTING FROM EASTERN CO TO MN BY EARLY MONDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z ARW/ARW2/GFS/UKMET/ECMWF
CONFIDENCE: AVERAGE
AHEAD OF THE DEEP WESTERN U.S. TROUGH/CLOSED LOW WILL BE MULTIPLE
SHORTWAVE TROUGHS THAT EJECT NORTHEAST OUT ACROSS THE PLAINS AND
MIDWEST. ONE SHORTWAVE IMPULSE THAT IS ALREADY EJECTING OUT ACROSS
EASTERN CO IS FORECAST TO ADVANCE UP OVER THE UPPER MIDWEST AND
AMPLIFY INTO POSSIBLY A WEAK CLOSED LOW OVER MN BY EARLY MONDAY AS
SOME MODEST ENERGY LIFTING NORTHEAST IN BEHIND IT MERGES AND
CONSOLIDATES WITH IT. THE GUIDANCE HAS TRENDED OVERALL A BIT
STRONGER WITH THIS FEATURE AND THE GLOBAL MODELS AND HREF SUITE OF
GUIDANCE SUPPORT AT LEAST A VIGOROUS CONVECTIVELY ENHANCED
SHORTWAVE REGIONALLY IMPACTING THE UPPER MIDWEST BY MONDAY. THERE
ARE SOME TIMING DIFFERENCES AS THE 00Z NAM IS A BIT SLOWER THAN
THE MODEL CONSENSUS, WITH THE 00Z CMC THE FASTEST. THE 00Z GFS,
00Z UKMET AND 00Z ECMWF ARE CLUSTERED IN BETWEEN CAMPS. OVERALL
THE CMC IS THE WEAKEST SOLUTION AND THE NAM THE STRONGEST. THE
LATEST HREF SUITE OF GUIDANCE LED BY THE ARW AND ARW2 SUPPORT THE
GFS SOLUTION. OVERALL, THE NMMB APPEARS A BIT TOO WEAK, AND THE
NAM-CONEST TOO SLOW. AT THIS POINT, ACCOUNTING FOR THE STRONGER
AND WEAKER SOLUTIONS, A BLEND OF THE GFS, UKMET AND ECMWF GLOBAL
MODELS ALONG WITH THE ARW AND ARW2 HIRES GUIDANCE WILL BE
PREFERRED.
SHORTWAVE LIFTING ACROSS THE CENTRAL PLAINS MONDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
A SHORTWAVE TROUGH THAT IS CURRENTLY OVER THE SOUTHWEST WILL LIFT
NORTHEAST AND REACH THE CENTRAL PLAINS BY MONDAY AND IS THEN
FORECAST TO DAMPEN OUT. THE LATEST MODELS ARE IN GOOD AGREEMENT ON
THE DETAILS OF THIS, SO A GENERAL MODEL BLEND WILL BE PREFERRED.
SHORTWAVE CROSSING THE RIO GRANDE VALLEY ON SUNDAY
AMPLIFYING TOWARD MID MS VALLEY BY MONDAY NIGHT
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z NAM/UKMET/ECMWF
CONFIDENCE: AVERAGE
THE GUIDANCE SUPPORTS A CONVECTIVELY ENHANCED SHORTWAVE OR MCV
LIFTING NORTHEAST ACROSS THE LOWER/MIDDLE RIO GRANDE VALLEY ON
SUNDAY WHICH IS FORECAST TO LIFT NORTHEAST TOWARD THE MID MS
VALLEY BY MONDAY NIGHT WHILE ATTEMPTING TO AMPLIFY. THE MODELS ALL
APPEAR TO BE TRENDING STRONGER WITH THIS FEATURE AND SUPPORT AT
LEAST A WEAK MID-LEVEL LOW CENTER IMPACTING THE TRI-STATE AREA OF
MO, IA AND IL GOING THROUGH TUESDAY. THE 00Z GFS ULTIMATELY ENDS
UP BEING MORE PROGRESSIVE AS IT SUGGESTS A FASTER INTERACTION
BETWEEN THIS IMPULSE AND THE UPSTREAM DEEP TROUGH OVER THE WEST.
THE 00Z CMC IS THE SLOWEST SOLUTION AND ALSO TAKES THE SYSTEM A
TAD FARTHER EAST. ALL OF THE 00Z HREF MODELS WITH EXCEPTION OF THE
NMMB FAVOR A REASONABLY WELL ORGANIZED MID-LEVEL SHORTWAVE TROUGH
OR WEAK CLOSED LOW CENTER APPROACHING THE MID MS VALLEY AS WELL.
FOR NOW, A BLEND OF THE 00Z NAM, 00Z UKMET AND 00Z ECMWF WILL BE
PREFERRED AS THIS APPEARS TO BEST APPROXIMATE THE MODEL CONSENSUS.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
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