647
FXUS10 KWNH 121656
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1155 AM EST TUE NOV 12 2019
VALID NOV 12/1200 UTC THRU NOV 16/0000 UTC
..SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z MODEL EVALUATION WITH PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..DEPARTING EAST COAST STORM SYSTEM TODAY/TONIGHT
..UPPER TROUGH PIVOTING THROUGH THE NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
NO SIGNIFICANT DIFFERENCES ARE NOTED IN THE GUIDANCE WITH THE
DEPARTING NEW ENGLAND LOW CENTER, AND COLD FRONT EXITING THE EAST
COAST. THE MODELS ARE ALSO IN GOOD AGREEMENT WITH THE DETAILS OF
THE DEEP UPPER TROUGH PIVOTING THROUGH THE NORTHEAST THROUGH EARLY
WEDNESDAY, SO A GENERAL MODEL BLEND WILL BE PREFERRED.
..SHORTWAVE TRACKING FROM THE NORTHWEST TO THE PLAINS BY WED
..CLOSED LOW DEVELOPMENT OVER THE SOUTHEAST
..CYCLOGENESIS OFF THE SOUTHEAST COAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND...THROUGH 48 HOURS
12Z GFS...AFTER 48 HOURS
CONFIDENCE: ABOVE AVERAGE...BECOMING BELOW AVERAGE AFTER 48 HOURS
THE MODELS SHOW GOOD AGREEMENT WITH THE DETAILS OF THE SHORTWAVE
CROSSING THE PACIFIC NORTHWEST AND DIGGING SOUTHEAST ACROSS THE
PLAINS THROUGH WEDNESDAY. ON THURSDAY, THIS ENERGY WILL BEGIN
SEPARATE OUT FROM THE WESTERLIES AND DIG DOWN ACROSS THE LOWER MS
AND TN VALLEYS. AS THIS ENERGY DROPS SOUTHEAST ACROSS THE GULF
COAST STATES, IT SHOULD INTERACT WITH AND CAPTURE ENERGY
ASSOCIATED WITH AN EJECTING SOUTHERN STREAM CLOSED LOW CROSSING
FROM MEXICO THROUGH SOUTH TEXAS AND THE WESTERN GULF OF MEXICO.
THE RESULT OF THIS INTERACTION WILL ULTIMATELY BE A CLOSED LOW
OVER THE SOUTHEAST BY FRIDAY, WITH COASTAL CYCLOGENESIS TAKING
PLACE JUST SOUTHEAST OF THE CAROLINAS. THE 12Z NAM OVERALL APPEARS
TO BE A BIT TOO STRONG WITH ITS SHORTWAVE AMPLIFICATION DOWN
ACROSS THE TN VALLEY AND GULF COAST STATES. MEANWHILE, THE 00Z
ECMWF APPEARS TO BE TOO SLOW WITH ITS PROGRESSION AND IS THE
SLOWEST DETERMINISTIC SOLUTION WITH THE CLOSED LOW. THE 00Z CMC IS
A WEAK OUTLIER ALOFT AND AT THE SURFACE AS THE SYSTEM REACHES THE
SOUTHEAST. THE 12Z GFS AND 00Z UKMET SHOW THE BEST CLUSTERING
ALOFT AND MORE CLOSELY APPROXIMATE THE MODEL CONSENSUS, BUT AT THE
SURFACE, THE UKMET APPEARS TO BE TOO FAR SOUTH WITH ITS COASTAL
CYCLOGENESIS. THERE IS A BIT OF SPREAD AMONG THE ENSEMBLE SUITES
WITH THE PLACEMENT OF THE COASTAL CYCLOGENESIS, BUT OVERALL THE
GFS HAS THE BETTER SUPPORT AT THE END OF THE PERIOD. WILL PREFER A
GENERAL MODEL BLEND THROUGH 48 HOURS, FOLLOWED BY A SOLUTION
TOWARD THE GFS THEREAFTER.
..MID-LEVEL SHORTWAVES APPROACHING THE WEST COAST ON THURSDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
A RELATIVELY WEAK MID-LEVEL SHORTWAVE IS EXPECTED TO APPROACH THE
OREGON/CALIFORNIA COASTLINES EARLY ON THURSDAY WHILE A SECOND
SHORTWAVE LURKS TO THE NORTH WITH A LIKELY DESTINATION OF
WASHINGTON/BRITISH COLUMBIA THURSDAY NIGHT. DESPITE SOME MINOR
TIMING DIFFERENCES OF THESE TWO FEATURES, AGREEMENT IS GOOD ENOUGH
TO WARRANT A GENERAL MODEL BLEND WHICH ALIGNS WITH THE LATEST
ENSEMBLE MEANS.
..CLOSED LOW DEVELOPMENT OFFSHORE SOUTHERN CALIFORNIA ON FRI
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 12Z GFS, 00Z UKMET AND 00Z ECMWF
CONFIDENCE: AVERAGE
ADDITIONAL SHORTWAVE ENERGY APPROACHING CALIFORNIA LATE THURSDAY
WILL BREAK AWAY AND DIG SOUTHEAST TO OFFSHORE SOUTHERN CALIFORNIA
ON FRIDAY, WITH THE GUIDANCE SUPPORTING A WEAK CLOSED LOW
EVOLUTION. THE 12Z NAM IS A WEAK AND MORE PROGRESSIVE OUTLIER
COMPARED TO THE GLOBAL MODEL SUITE. OF THE GLOBAL MODELS, THE 12Z
GFS, 00Z UKMET AND 00Z ECMWF SHOW THE BEST MODEL CLUSTERING, AND
HAVE SUPPORT FROM THE 00Z ECENS MEAN. THEREFORE, A BLEND OF THESE
SOLUTIONS 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
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