423
FXUS10 KWNH 191623
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1122 AM EST SUN JAN 19 2020
VALID JAN 19/1200 UTC THRU JAN 23/0000 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z MODEL EVALUATION WITH LATEST PREFERENCES AND FORECAST
CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~
..SHORTWAVE/FRONT CLIPPING THE PACIFIC NORTHWEST BY MONDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE GUIDANCE IS GENERALLY IN GOOD AGREEMENT WITH THE PROGRESSIVE,
LOW-AMPLITUDE NATURE OF THIS SYSTEM BRUSHING BY THE PACIFIC
NORTHWEST ON MONDAY. GIVEN THE VERY MODEST MODEL MASS FIELD
SPREAD, A GENERAL MODEL BLEND WILL BE PREFERRED.
..AMPLIFYING SHORTWAVE CROSSING THE MIDWEST THROUGH MONDAY
..CLOSED LOW EVOLUTION OVER THE SOUTHEAST BY TUESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
A PROGRESSIVE, BUT VIGOROUS, NORTHERN STREAM SHORTWAVE WILL DIG
SOUTHEAST FROM CANADA AND CROSS THE UPPER MIDWEST TONIGHT BEFORE
THEN SWINGING DOWN THROUGH THE OH/TN VALLEYS ON MONDAY. BY
TUESDAY, THE SYSTEM WILL DEEPEN INTO A CLOSED LOW OVER THE
SOUTHEAST BEFORE GOING OUT TO SEA. MODEL SPREAD WITH THIS HAS
DECREASED COMPARED TO YESTERDAY, AND THE GUIDANCE GENERALLY SHOWS
VERY GOOD TIMING/DEPTH AGREEMENT, SO A GENERAL MODEL BLEND WILL BE
PREFERRED.
..SOUTHERN STREAM SHORTWAVE CROSSING CALIFORNIA BY MONDAY
..ENERGY CROSSING THE SOUTHWEST/PLAINS TUESDAY AND WEDNESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~
PREFERENCE: NON-GFS BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
SOUTHERN STREAM SHORTWAVE ENERGY WILL BE CROSSING SOUTHERN AREAS
OF CALIFORNIA ON MONDAY AHEAD OF A DEEP UPPER TROUGH/CLOSED LOW
OFFSHORE OF THE PACIFIC NORTHWEST. THIS ENERGY WILL THEN EJECT
QUICKLY DOWN ACROSS THE SOUTHWEST ON TUESDAY AND EJECT EAST ACROSS
THE PLAINS ON WEDNESDAY. THE 12Z GFS HAS AT LEAST TRENDED A TAD
DEEPER AND SLOWER WITH THIS SYSTEM, AND TOWARD THE ALREADY
RELATIVELY DEEPER/SLOWER 12Z NAM AND 00Z NON-NCEP SUITE OF
GUIDANCE. THE NAM BY THE END OF THE PERIOD MAY BE JUST A TAD TOO
DEEP WITH ITS TROUGH OVER THE SOUTHERN PLAINS, BUT IT IS
DEFINITELY NOT OUTSIDE THE BROADER ENSEMBLE ENVELOPE, ESPECIALLY
RELATIVE TO THE ECENS SUITE. ON THE FLIP SIDE, THE GFS OVERALL MAY
STILL BE A TAD TOO PROGRESSIVE AT THE END OF THE PERIOD, AND THERE
ARE CONCERNS WITH ITS HEIGHT FALLS EVOLUTION UPSTREAM OVER THE
PACIFIC NORTHWEST AND THE NORTHERN HIGH PLAINS. DESPITE THE
FAVORABLE GFS MASS FIELD TRENDS ACROSS THE SOUTHERN TIER, THE
PREFERENCE WILL STILL BE TO LIMIT THE GFS INCORPORATION INTO THE
MODEL PREFERENCE. SO, BASED ON THESE LATEST TRENDS AND CLUSTERING,
A NON-GFS BLEND WILL BE PREFERRED.
..UPPER TROUGH/CLOSED LOW OVER THE PACIFIC NORTHWEST BY TUESDAY
..ENERGY EJECTING OUT ACROSS THE NORTHERN PLAINS WEDNESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~
PREFERENCE: NON-GFS BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
A DEEP UPPER TROUGH AND ASSOCIATED CLOSED LOW WILL ARRIVE ACROSS
THE PACIFIC NORTHWEST ON TUESDAY, WITH THE ENERGY THEN QUICKLY
ADVANCING EAST ACROSS THE NORTHERN PLAINS ON WEDNESDAY. THE 12Z
GFS IS OUT OF TOLERANCE WITH THE 12Z NAM, AND THE ENTIRE NON-NCEP
SUITE OF GUIDANCE. IT GENERALLY BECOMES A SLOWER AND RELATIVELY
DEEPER OUTLIER AS IT CROSSES PACIFIC NORTHWEST, AND DOWN TOWARD
THE HIGH PLAINS. THERE IS SOME MODEST SUPPORT FROM THE GEFS
ENSEMBLE SUITE FOR THE GFS, BUT THE ECENS/CMCE CAMPS ARE IN FAVOR
OF THE NON-NCEP CONSENSUS, ALONG WITH THE NAM. AS A RESULT, A
NON-GFS BLEND WILL BE PREFERRED.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
ORRISON
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page