010
FXUS10 KWNH 051835
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
234 PM EDT SUN JUL 05 2020
VALID JUL 05/1200 UTC THRU JUL 09/0000 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z MODEL EVALUATION INCLUDING PREFERENCES AND FORECAST CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
19Z UPDATE: NO SIGNIFICANT CHANGES NOTED WITH THE REST OF THE 12Z
GUIDANCE. THE UKMET REMAINS A BIT OF AN OUTLIER ACROSS THE GULF
COAST AND SOUTHEAST, ESPECIALLY IN THE DAY 2/3 TIME FRAME, THOUGH
THE LATEST MODEL CYCLE DID TREND TOWARD CONSENSUS.
TROUGH BUILDING OVER THE NORTHEAST U.S. THIS WEEKEND
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
NORTHWEST FLOW SHORTWAVE TROUGH ENERGY WILL MOVE ACROSS THE
NORTHEAST AND NEW ENGLAND MONDAY AND IS QUICKLY REPLACED BY BRIEF
RIDGING FOR TUESDAY. BY MID-WEEK, THERE ARE HINTS OF A WEAK
SHORTWAVE TROUGH SKIRTING PORTIONS OF NORTHERN NEW ENGLAND.
OVERALL, MODEL GUIDANCE IS FAIRLY AGREEABLE THROUGH THE PERIOD
WITH SOME MINOR SPEED DIFFERENCES NOTED, WHERE THE GFS IS A TOUCH
FASTER AND THE UKMET SLOWER. THE CMC HAS HIGHER HEIGHTS AT 500 MB
AND IS A BIT FLATTER IN GENERAL, BUT ALL TOGETHER, THE DIFFERENCES
DON'T PRECLUDE GOING WITH A GENERAL MODEL BLEND AT THIS TIME.
TROUGH/WEAKNESS OVER THE GULF COAST REGION
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-UKMET BLEND
CONFIDENCE: AVERAGE
BROAD WEAKNESS IN THE LARGER SCALE UPPER RIDGE OVER THE SOUTHEAST
AND DEEP SOUTH WILL REMAIN IN PLACE OVER THE NEXT SEVERAL DAYS
WITH SOME SUGGESTION IN THE LATEST GUIDANCE OF MORE ORGANIZED
SHORTWAVE ENERGY OFF THE GA/SC COAST BY MID-WEEK. MODEL GUIDANCE
HAS CONSOLIDATED BETTER OVER THE LAST COUPLE OF CYCLES AND LARGELY
AGREE ON THE EVOLUTION THROUGH 84 HOURS. THE MAIN EXCEPTION IS THE
UKMET, WHICH SHOWS A FASTER PROGRESSION OF THE WEAKNESS/ENERGY OFF
THE SOUTHEAST COAST COMPARED TO THE REST OF THE DETERMINISTIC
GUIDANCE. FOR THIS REASON, A NON-UKMET BLEND IS STILL PREFERRED.
TROUGH WITH MULTIPLE SHORTWAVES ACROSS THE PACIFIC NORTHWEST AND
CANADA
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-UKMET BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
WITHIN THE BROAD TROUGH OVER THE PACIFIC NORTHWEST, A STRONGER
SHORTWAVE TROUGH APPROACHES WA/OR LATE MONDAY INTO TUESDAY. ASIDE
FROM A SLIGHTLY DEEPER GFS/NAM, MODEL AGREEMENT IS VERY GOOD WITH
THIS SYSTEM. EVENTUALLY THE ENERGY WORKS THROUGH THE NORTHERN
ROCKIES AND IS FORECAST TO CLOSE OFF OVER THE SOUTHERN CANADIAN
ROCKIES. THE CMC IS FLATTER/OPEN THE MOST AND DOESN'T SUGGEST A
CLOSED LOW FORMS WHILE THE ECMWF IS DISPLACED TO THE WEST COMPARED
TO THE NEARLY IDENTICAL GFS/UKMET POSITION. THE NAM DOES
EVENTUALLY DEVELOP THE CLOSED LOW, BUT IS 6-12 HOURS LATER.
FINALLY, ANOTHER SYSTEM WILL THEN APPROACH THE PACIFIC NORTHWEST
MID-WEEK. HERE, THE UKMET IS SLOWER AND BUT THE REST OF THE
GUIDANCE SHOWS GOOD CLUSTERING. FOR THESE REASONS, A NON-UKMET
BLEND IS PREFERRED FOR THIS REGION.
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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