844
FXUS10 KWNH 230656
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
255 AM EDT SAT MAY 23 2020
VALID MAY 23/0000 UTC THRU MAY 26/1200 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION INCLUDING LATEST PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..CUT-OFF LOW IMPACTING THE OH VALLEY AND NORTHERN MID-ATLANTIC
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS ARE IN VERY GOOD AGREEMENT WITH THE DETAILS OF THE
CUT-OFF UPPER LOW CURRENTLY OVER THE UPPER OH VALLEY WHICH WILL
ADVANCE EAST ACROSS THE NORTHERN MID-ATLANTIC REGION ON SATURDAY
AND THEN MOVE OFFSHORE. A GENERAL MODEL BLEND WILL BE PREFERRED
WITH THIS SYSTEM.
..DEEP UPPER TROUGH/CLOSED LOW RELOADING OVER THE WESTERN U.S
..EJECTING OUT OVER THE PLAINS BY TUESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND...THROUGH 48 HOURS
00Z GEFS MEAN/12Z ECENS MEAN BLEND...AFTER 48 HOURS
CONFIDENCE: AVERAGE...BECOMING BELOW AVERAGE AFTER 48 HOURS
THE LATEST GUIDANCE SHOWS VERY GOOD AGREEMENT IN BRINGING A NEW
LARGE SCALE UPPER TROUGH AND ASSOCIATED CLOSED LOW IN ACROSS THE
INTERMOUNTAIN WEST THIS WEEKEND. BY EARLY NEXT MONDAY, THE
CONSENSUS OF GUIDANCE SUPPORTS A DEEP TROUGH EDGING TOWARD THE
PLAINS WITH ONE CLOSED LOW CENTER EXITING THE NORTHERN ROCKIES AND
CROSSING THE NORTHERN HIGH PLAINS BY THEN. MEANWHILE, A SECOND
CLOSED LOW WILL BE ATTEMPTING TO FOCUS OVER THE CENTRAL ROCKIES BY
THEN, AND BY TUESDAY, THE GUIDANCE IS IN REASONABLY GOOD AGREEMENT
ON THE IDEA OF THIS CLOSED LOW BECOMING BETTER DEFINED OUT ACROSS
THE SOUTHERN HIGH PLAINS. THIS WILL RESULT IN A CORRESPONDING
SURFACE LOW, AND WITH THIS FEATURE THERE IS A FAIR DEGREE OF MODEL
MASS FIELD SPREAD. THE 00Z CMC HAS A WEAKER AND NORTHERLY TRACKING
LOW CENTER UP OVER SOUTHWEST MO AT THE END OF THE PERIOD VERSUS
THE 00Z UKMET WHICH IS THE STRONGEST SOLUTION AND HAS IT DOWN OVER
SOUTHWEST OK. THE 00Z NAM AND 00Z GFS SOLUTIONS ARE SPREAD FROM
CENTRAL TO EASTERN OK RESPECTIVELY, AND THE 00Z ECMWF NOW HAS A
LOW CENTER OVER SOUTHERN OK. OVERALL, BASED ON THE TRENDS AND
CLUSTERING, IT WOULD APPEAR THAT THE CMC IS THE TRUE OUTLIER
SOLUTION. THE 00Z GEFS MEAN AND 12Z ECENS MEAN BOTH HAVE A
WELL-DEFINED FRONT ACROSS THE PLAINS AND STRETCHING UP TOWARD THE
UPPER MIDWEST BY THE END OF THE PERIOD, BUT DO NOT NECESSARILY
SUGGEST A WELL-DEFINED LOW AT THIS POINT, AND UPON INSPECTION OF
INDIVIDUAL MEMBERS, THERE IS SIGNIFICANT SPREAD WITH THE DETAILS
OF SURFACE WAVE ACTIVITY ALONG THE FRONT OVER THE CENTRAL AND
SOUTHERN PLAINS REGION FROM MONDAY INTO TUESDAY. A GENERAL MODEL
BLEND SHOULD GENERALLY SUFFICE WITH THIS ENTIRE MASS FIELD
EVOLUTION THROUGH 48 HOURS, BUT THEREAFTER AS THE DEEP
TROUGH/CLOSED LOW EJECTS OUT ACROSS THE PLAINS, A BLEND OF THE
LATEST GEFS MEAN AND ECENS MEAN WILL BE PREFERRED GIVEN THE LARGE
SPREAD IN THE DETAILS OF SURFACE LOW PRESSURE. FORTUNATELY, THERE
IS REASONABLY GOOD AGREEMENT WITH THE DETAILS OF THE ENERGY ALOFT
AT THIS TIME.
..SHORTWAVE/CLOSED LOW CROSSING THE MIDWEST THROUGH SATURDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-UKMET BLEND
CONFIDENCE: ABOVE AVERAGE
THE LATEST GOES-WV SATELLITE IMAGERY SHOWS A VERY WELL-DEFINED
CLOSED LOW OVER FAR SOUTHEAST NE WHICH WILL BE ADVANCING NORTHEAST
ACROSS THE UPPER MIDWEST THROUGH SATURDAY AND THEN GRADUALLY
WEAKENING OVER THE GREAT LAKES REGION ON SUNDAY AS IT ATTEMPTS TO
CREST THE DEEP LAYER RIDGE FORMING AND NOSING NORTHWARD BY THEN
OVER THE OH/TN VALLEYS AND SOUTHEAST. OVERALL, THE GUIDANCE IS IN
GOOD AGREEMENT WITH THIS SYSTEM, BUT THE 00Z UKMET AFTER ABOUT 48
HOURS HANGS ONTO A SOMEWHAT STRONGER TROUGH THAT EXITS THE GREAT
LAKES AND MOVES INTO PORTIONS OF NORTHERN NEW ENGLAND BY EARLY
MONDAY. GIVEN GOOD CLUSTERING IN THE GUIDANCE OTHERWISE, A
NON-UKMET BLEND WILL BE PREFERRED.
...SHORTWAVE LIFTING NORTHEAST ACROSS THE SOUTHERN PLAINS
SUNDAY...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
AS THE DEEP TROUGH AND ASSOCIATED CLOSED LOW EVOLVES ACROSS THE
WEST THIS WEEKEND AND SLOWLY ENCROACHES ON THE HIGH PLAINS, THERE
WILL BE A SHORTWAVE TROUGH ROUNDING THE BASE OF IT AND LIFTING
NORTHEAST ACROSS THE SOUTHERN PLAINS ON SUNDAY. THE 00Z NON-NCEP
MODELS TRENDED STRONGER WITH THE ENERGY LIFTING NORTHEAST ACROSS
THE REGION AND HAVE BETTER AGREEMENT WITH THE 00Z NAM/GFS
SOLUTIONS. THIS WOULD SUGGEST THE POTENTIAL FOR A MORE DISCREET
MID-LEVEL LOW CENTER DEVELOPING OVER CENTRAL TX BY SUNDAY NIGHT OR
MONDAY MORNING THAT WOULD BE EMBEDDED WITHIN THE NORTHEAST
ADVANCING SHORTWAVE TROUGH. BASED ON THE LATEST TRENDS AND
DETERMINISTIC CLUSTERING, A GENERAL MODEL BLEND WILL BE PREFERRED.
..MID-LEVEL TROUGH IMPACTING SOUTHERN FL MONDAY AND TUESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-UKMET BLEND
CONFIDENCE: AVERAGE
AS A STRONG SUBTROPICAL RIDGE BUILDS OVER THE SOUTHEAST AND THE
MID-ATLANTIC REGION SUNDAY AND MONDAY, THERE WILL BE A MID-LEVEL
TROUGH AXIS LIFTING NORTH FROM NEAR THE YUCATAN PENINSULA AND
WESTERN CARIBBEAN SEA INTO THE SOUTHERN GULF OF MEXICO. THIS
ENERGY IS EXPECTED TO ELONGATE AND CROSS AREAS OF SOUTHERN FL BY
LATE MONDAY AND THROUGH TUESDAY. THE 00Z NAM/GFS SOLUTIONS AND THE
00Z CMC/ECMWF SOLUTIONS ALL FAVOR A TROUGH AXIS THAT ADVANCES A
BIT FARTHER NORTH VERSUS THE MORE SUPPRESSED 00Z UKMET. THERE HAS
BEEN A MULTI-MODEL TREND TO FOCUS A STRONGER MID-LEVEL TROUGH A
BIT FARTHER NORTH OVER THE SOUTHEAST GULF OF MEXICO AND SOUTHERN
FL FOR MONDAY AND TUESDAY, AND SO THE UKMET APPEARS TO BE
GENERALLY AN OUTLIER SOLUTION AT THIS POINT. A NON-UKMET BLEND
WILL BE PREFERRED AS A RESULT.
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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