263
FXUS10 KWNH 150744
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
343 AM EDT WED APR 15 2020
VALID APR 15/0000 UTC THRU APR 18/1200 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION WITH PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..SHORTWAVE ENERGY MOVING ACROSS MIDWEST/OHIO VALLEY DAY 2/3
---------------------
MODEL BLEND PREFERENCE: 00Z ECMWF, ECENS MEAN, AND UKMET
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
07Z UPDATE: NO MAJOR CHANCES NOTED WITH THE REST OF THE 00Z
GUIDANCE FOR THIS FEATURE ON DAY 3. THE NON-NCEP GUIDANCE REMAINS
FAVORED.
---PREVIOUS DISCUSSION---
SHORTWAVE ENERGY MOVING THROUGH THE INTER-MOUNTAIN WEST IS
EXPECTED TO SHEAR TO THE EAST ACROSS PORTIONS OF THE MIDWEST/OHIO
VALLEY FRIDAY AS IT BECOMES ABSORBED INTO THE WESTERLY MEAN FLOW.
AS THIS HAPPENS AND INFLUENCE FROM NORTHERN STREAM ENEGY OVER THE
GREAT LAKES, A WEAK SURFACE LOW IS FORECAST TO DEVELOP AND MOVE
THROUGH THE OHIO VALLEY. THE GFS AND NAM ARE TOO PROGRESSIVE/NORTH
AND STRONG WITH THE SHORTWAVE ENERGY AND THEREFORE HAVE A MUCH
DEEPER LOW AT THE SURFACE. THE ECMWF/UKMET AND ECENS MEAN HAS BEEN
CONSISTENTLY A MORE FAVORABLE SOLUTION AND REMAINS THE PREFERRED
BLEND FOR MASS FIELDS AND QPF FOR THIS TIME FRAME.
WESTERN/CENTRAL CONUS
--------------------
MODEL BLEND PREFERENCE: GENERAL MODEL BLEND DAY 1/2, 00Z
ECMWF/UKMET/ECENS MEAN BLEND DAY 3
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
07Z UPDATE: NO SIGNIFICANT CHANGES WITH THE REST OF THE 00Z
GUIDANCE. THE 00Z ECMWF CONTINUES TO SHOW FAIRLY GOOD CONSISTENCY
AND WILL BE INCORPORATED INTO THE LATEST MODEL BLEND PREFERENCE.
---PREVIOUS DISCUSSION---
ANOMALOUS UPPER LEVEL RIDGE OVER THE EASTERN PACIFIC BEGINS TO
BREAK DOWN AS A SHORTWAVE TROUGH UNDERCUTS ITS AND THEN CLOSES
OFFSHORE THE WESTERN U.S. COAST. THROUGH 48 HOURS, THERE IS VERY
GOOD AGREEMENT WITH THE DEPTH AND PROGRESSION OF THIS FEATURE AND
EVEN INTO DAY 3 AS THE SYSTEM OPENS UP OVER THE SOUTHWEST, THERE
IS FAIRLY GOOD AGREEMENT. THE UKMET IS A BIT FASTER THAN THE REST
OF THE GUIDANCE AND NOW THE GFS IS ON THE SLOWER SIDE BUT FOR THE
MOST PART, A GENERAL MODEL BLEND FOR THIS FEATURE IS PREFERRED.
SHORTWAVE ENERGY WILL ALSO MOVE THROUGH THE NORTHERN ROCKIES AND
THEN ACROSS THE INTER-MOUNTAIN WEST IN THE DAY 1/2 TIME FRAME. THE
00Z GFS/NAM QUICKLY BECOME UNUSABLE AFTER ABOUT 36 HOURS AS THE
SHORTWAVE IS TOO STRONG AND TOO FAST COMPARED TO THE REST OF THE
GUIDANCE AND THE ENSEMBLE MEANS. ESPECIALLY BY DAY 3 /FRIDAY/ THE
GFS BEGINS TO SHEAR THE SHORTWAVE TOO STRONGLY TO THE EAST,
STRINGING OUT THE VORTICITY LOBE FASTER THAN THE REMAINING
GUIDANCE. FOR THESE REASONS A ECMWF/ECENS MEAN/UKMET IS PREFERRED
FOR MOST OF THE WEST D3 AS THEY ARE CONSISTENT AND MATCH WELL TO
EACH OTHER.
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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