850
FXUS10 KWNH 230719
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
318 AM EDT TUE JUN 23 2020
VALID JUN 23/0000 UTC THRU JUN 26/1200 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION INCLUDING PREFERENCES AND FORECAST CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CLOSED LOW OVER ONTARIO/QUEBEC
SHORTWAVES OVER THE LOWER MS/OH VALLEYS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
THE LARGE CLOSED UPPER LOW OVER WESTERN ONTARIO IS EXPECTED TO
SLOWLY ADVANCED EASTWARD OVER THE NEXT 3 DAYS, SETTLING INTO
WESTERN QUEBEC BY THE END OF THE FORECAST PERIOD. IN THE SYNOPTIC
SENSE, ALL THE MODELS SHOW AVERAGE TO ABOVE AVERAGE CONSISTENCY
AND AGREEMENT FROM THE PAST FEW RUNS. THE MAIN DIFFERENCES LIE ON
THE PERIPHERY OF THE TROUGHING WHERE MULTIPLE CONVECTIVELY INDUCED
SHORTWAVES PUSH ACROSS THE CENTRAL PLAINS TO MS RIVER VALLEY AND
INTO THE OHIO VALLEY. A GENERAL MODEL BLEND SUFFICES FROM A MASS
FIELD SYNOPTIC SENSE BUT MORE MESOSCALE DRIVEN DIFFERENCES
INCLUDING QPF CAN BE EXPECTED HOWEVER.
TROUGHS APPROACHING BRITISH COLUMBIA AND PACIFIC NORTHWEST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: UKMET/GFS/NAM BLEND
CONFIDENCE: AVERAGE
07Z UPDATE: THE 00Z ECMWF REMAINED A FLATTER, FASTER SOLUTION
THOUGH IT BACKED OFF FROM ITS 12Z RUN SOMEWHAT. HOWEVER, IT STILL
APPEARS TO BE TOO FAR AHEAD FROM THE OTHER DETERMINISTIC GUIDANCE
AND WILL CONTINUE TO PREFER A BLEND CONSISTING OF THE
GFS/UKMET/NAM.
---PREVIOUS DISCUSSION---
SHORTWAVE TROUGH ENERGY WILL MOVE THROUGH PACIFIC NORTHWEST INTO
THE CENTRAL/NORTHERN ROCKIES OVER THE NEXT COUPLE OF DAYS, WITH A
MORE SIGNIFICANT SHORTWAVE TROUGH APPROACHING THE REGION ON
WEDNESDAY NIGHT INTO THURSDAY. AS HAS BEEN THE CASE THE LAST
SEVERAL RUNS, THE ECMWF HAS SHOWN A FLATTER, MORE PROGRESSIVE FLOW
PATTERN THAT IS OUT OF SYNC WITH THE REST OF THE DETERMINISTIC
GUIDANCE WHICH ADVERTISES A SLOWER, MORE AMPLIFIED TROUGH THAT
DIGS OVER THE ROCKIES INTO THE DAY 3 PERIOD. MEANWHILE THE GFS
REMAINS A SLOWER SOLUTION AND HAS STRONG SUPPORT FROM ITS ENSEMBLE
MEAN AS WELL. WHILE THE UKMET/NAM OFFER A MIDDLE GROUND SOLUTION,
THEY DO LEAN TOWARD A SLOWER APPROACH SIMILAR TO THE GFS, LEAVING
THE ECMWF AS MORE AN OUTLIER AT THIS TIME.
MID-LEVEL ENERGY LINGERING OVER THE LOWER MS VALLEY/TEXAS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
LINGERING UPPER LEVEL ENERGY THAT IS EXPECTED TO BECOME REMOVED
FROM THE WESTERLIES WILL SLOWLY MEANDER OVER THE LOWER MS RIVER
VALLEY AND TEXAS AREAS WHILE TOWARD THE DAY 2/3 TIME FRAME, WEAK
TROPICAL ENERGY FROM THE WESTERN GULF APPROACHES TX/LA. MUCH OF
THE MODEL DIFFERENCES WILL LIE IN THE MESOSCALE SECTOR BUT ON A
SYNOPTIC SCALE A GENERAL MODEL BLEND SUFFICES.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
TAYLOR
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