778
FXUS10 KWNH 140651
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
151 AM EST FRI FEB 14 2020
VALID FEB 14/0000 UTC THRU FEB 17/1200 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION WITH PREFERENCES & CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CENTRAL AND EASTERN CONUS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
07Z UPDATE: NO SIGNIFICANT CHANGES NOTED WITH THE REST OF THE 00Z
GUIDANCE AND THE ORIGINAL MODEL BLEND PREFERENCE REMAINS.
RELATIVELY QUIET SYNOPTIC PATTERN EXPECTED ACROSS THE CONUS
THROUGH THE NEXT 3 DAYS. INITIALLY THE FLOW WILL DOMINATED BY A
LARGE ARCTIC HIGH PRESSURE MOVING FROM THE UPPER MIDWEST TOWARD
THE OHIO VALLEY THROUGH FRIDAY. THIS WILL CONTINUE TO SHUNT THE
SLOW MOVING, LINGERING WARM CONVEYOR/FRONTAL ZONE ACROSS THE FAR
EASTERN US. OVERALL, THE LATEST (14.00Z) GUIDANCE REMAINS IN
EXCELLENT AGREEMENT WITH THE PROGRESSION OF THIS FEATURE SUCH THAT
A GENERAL MODEL BLEND FOR DAY 1.
A SECONDARY SHORTWAVE TROUGH CLIPS THE NORTHERN PLAINS AND GREAT
LAKES REGION WHICH SHOULD PASS WITHOUT MUCH ACTIVITY OTHER THAN TO
REINFORCE SOME OF THE ARCTIC AIR AND A CONTINUATION OF THE LAKE
EFFECT SNOWS. AS SUCH, WITH THE FAVORABLE MODEL AGREEMENT AND
RELATIVE QUIETER PATTERN, A GENERAL MODEL BLEND CAN BE USED FOR
THE CENTRAL AND EASTERN CONUS.
PACIFIC NORTHWEST SHORTWAVE DAY 3
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: ECENS/GEFS MEAN BLEND
CONFIDENCE: BELOW AVERAGE
07Z UPDATE: THE 00Z ECMWF/CMC/UKMET DID NOT OFFER ANY BETTER
CONSENSUS TO THE SHORTWAVE PROGRESSION ON DAY 3 AND IT STILL SHOWS
QUITE A BIT OF VARIABILITY IN TIMING AND AMPLIFICATION ACROSS THE
PACIFIC NORTHWEST. THE 00Z NAM NOW APPEARS TOO AMPLIFIED AND THE
00Z ECMWF IS UNCHARACTERISTICALLY FAST. GIVEN THE HIGHER THAN
USUAL VARIABILITY, A SOLUTION GEARED TOWARD THE ECENS/GEFS MEANS
SEEMS APPROPRIATE FOR DAY 3.
A COMPACT BUT AMPLIFIED SHORTWAVE TROUGH WILL CROSS THROUGH THE
GULF OF ALASKA TOWARD SOUTHERN BC AND WASHINGTON STATE ON DAY 3.
THERE REMAINS SOME SIZABLE TIMING DIFFERENCES DUE TO AMPLIFICATION
OF UPSTREAM RIDGING IN ITS WAKE. THE UKMET IS SLOWER AND MORE
AMPLIFIED WHILE THE CMC IS FLATTER AND MORE PROGRESSIVE. THIS PUTS
THE ECMWF/GFS IN THE MIDDLE GROUND YET THESE MODELS ARE ALSO
SHOWING SOME DIFFERENCES, WHERE THE GFS IS A BIT SLOWER THAN THE
ECMWF. THE 00Z NAM ALSO COULD BE INCLUDED IN A BLEND WITH ITS
SIMILAR SOLUTION TO THE GFS AND ECMWF AT THIS POINT. OVERALL, DUE
TO THESE TIMING DIFFERENCES MODEL FORECAST CONFIDENCE IS AT
SLIGHTLY BELOW AVERAGE.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
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