471
FXUS10 KWNH 151649
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1149 AM EST SUN DEC 15 2019
VALID DEC 15/1200 UTC THRU DEC 19/0000 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z EVALUATION WITH PREFERENCES AND FORECAST CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
...MID-LEVEL TROUGH TRACKING FROM THE WESTERN U.S. TO THE EASTERN
U.S. WEDNESDAY MORNING...
...SURFACE LOW ORGANIZING EAST OF THE MISSISSIPPI RIVER MONDAY
INTO TUESDAY MORNING...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GFS/ECMWF BLEND
CONFIDENCE: AVERAGE
FAIRLY GOOD AGREEMENT NOW EXISTS BETWEEN THE GLOBAL MODELS WITH
THE STORM SYSTEM MOVING THROUGH THE CENTRAL/EASTERN U.S. OVER THE
FORECAST PERIOD. ALOFT, THERE IS LITTLE DIFFERENCE BETWEEN THE
VARIOUS MODELS FOR THE STRENGTH AND POSITION AT 500/300 MB. SOME
DIFFERENCES REMAIN AT THE SURFACE, PARTICULARLY AS THE LOW MOVES
OFFSHORE THE NORTHEAST / NEW ENGLAND COASTS. THE CMC IS SLOWER AND
FURTHER SOUTH WHILE THE GFS IS A TOUCH FASTER. BUT OVERALL A
GENERAL MODEL BLEND SHOULD YIELD A REASONABLE SOLUTION.
...MID-LEVEL SHORTWAVE CLIPPING THE GREAT LAKES TUESDAY INTO
WEDNESDAY...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
A DEEP BUT COMPACT CLOSED LOW SWINGS THROUGH THE NORTHERN GREAT
LAKES REGION TUESDAY. MODEL AGREEMENT IS ABOVE AVERAGE NOW. SOME
MINOR DIFFERENCES DEVELOP WITH THE SURFACE LOW TRACK (GFS A BIT
SOUTH COMPARED TO THE CONSENSUS) BUT OVERALL A GENERAL MODEL BLEND
WILL SUFFICE FOR THIS AREA DURING THIS TIME.
..TROUGH APPROACHING THE WESTERN U.S. TUESDAY EVENING
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GFS/ECMWF BLEND
CONFIDENCE: BELOW AVERAGE
THERE CONTINUES TO BE FAIRLY SIZABLE DIFFERENCES IN THE MODEL
GUIDANCE WITH THE NEXT SYSTEM TO MOVE THROUGH THE WESTERN U.S.
TUESDAY NIGHT INTO WEDNESDAY. RIDGING ALOFT INITIALLY IS OF
SIMILAR STRENGTH/POSITION BY THE GLOBAL MODELS, BUT A MID/UPPER
LEVEL SHORTWAVE WILL NEAR THE COAST TUESDAY. SOME GUIDANCE
ADVERTISES THIS AS A CLOSED LOW WHILE OTHERS REMAIN OPEN. THE 00Z
UKMET AND 00Z CMC WERE THE FAST OUTLIERS AND MOSTLY REMOVED FROM
THE BLEND PREFERENCE. AT THE SURFACE, WAVY LOW PRESSURE WILL LIFT
WELL NORTH OF THE 500 MB SHORTWAVE AND THERE ARE SOME CONSIDERABLE
DIFFERENCES HERE. AS SUCH, WILL LEAN ON A GFS/ECMWF BLEND
PRIMARILY, WITH SOME INCLUSION OF THE CMC THROUGH 60 HOURS.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
TAYLOR
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