443
FXUS10 KWNH 030500
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1259 AM EDT MON AUG 03 2020
VALID AUG 03/0000 UTC THRU AUG 06/1200 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION INCLUDING PREFERENCES AND FORECAST CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..SHORTWAVE/LOW CENTER EXITING THE LOWER GREAT LAKES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE GUIDANCE IS IN VERY GOOD AGREEMENT ON THE DETAILS OF THE
EXITING SHORTWAVE/SURFACE LOW OVER THE LOWER GREAT LAKES REGION,
SO A GENERAL MODEL BLEND WILL BE PREFERRED WITH THIS SYSTEM.
..TROPICAL STORM ISAIAS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 03Z NHC ADVISORY PACKAGE
BEST MODEL PROXY: 18Z GEFS MEAN
THE 03Z NHC FORECAST TRACK OF TROPICAL STORM ISAIAS IS GENERALLY
IN BETWEEN THE FASTER 00Z GFS/12Z CMC SOLUTIONS AND THE SLOWER 00Z
NAM/12Z UKMET AND 12Z ECMWF SOLUTIONS. HOWEVER, THE NHC TRACK IS
OVERALL A BIT TO THE RIGHT OF ALL OF THE GLOBAL MODEL GUIDANCE
THROUGH 48 HOURS AS THE STORM APPROACHES AND MAKES LANDFALL ACROSS
THE CAROLINAS AND LIFTS THROUGH THE MID-ATLANTIC STATES. THE SAME
APPLIES TO ALL OF THE 00Z HREF SUITE OF GUIDANCE THROUGH 48 HOURS,
ALTHOUGH THE 00Z ARW IS FAIRLY CLOSE A TAD LEFT OF THE NHC TRACK.
THEREAFTER, AS THE SYSTEM ADVANCES RAPIDLY THROUGH THE NORTHEAST,
THE UKMET/ECMWF SOLUTIONS BRING THEIR TRACKS A BIT EAST OF THE NHC
TRACK. THE 12Z ECENS MEAN STILL FAVORS THE SLOWER GUIDANCE, BUT
THE 18Z GEFS MEAN DOES A NICE JOB OF FAVORING A COMPROMISE BETWEEN
THE FASTER AND SLOWER GLOBAL MODEL CAMPS, AND APPEARS TO BE THE
BEST MODEL PROXY AT THIS TIME TO THE LATEST NHC TRACK EVEN THOUGH
THE GEFS MEAN IS A TAD LEFT OF THE NHC FORECAST. PLEASE CONSULT
THE LATEST NHC FORECAST ADVISORY PACKAGE FOR MORE DETAILS.
..BROAD TROUGH FROM THE GREAT LAKES TO THE GULF COAST
..CLOSED LOW OVER ONTARIO
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
A BROAD TROUGH EXTENDING FROM THE GREAT LAKES DOWN TO THE CENTRAL
GULF COAST ON MONDAY WILL BE KEY IN ALLOWING TROPICAL STORM ISAIAS
TO LIFT NORTH AND THEN NORTH-NORTHEAST UP ALONG THE EASTERN
SEABOARD OVER THE NEXT 48 TO 72 HOURS. THE MODELS ARE IN GOOD
AGREEMENT IN MAINTAINING THE BROAD TROUGH THROUGH THE PERIOD, BUT
WITH SOME STRONGER NORTHERN STREAM ENERGY OVER THE GREAT LAKES
REGION FAVORING A CLOSED LOW EVOLUTION UP OVER ONTARIO. SUFFICIENT
AGREEMENT IS NOTED WITH THE GLOBAL MODELS SUCH THAT A GENERAL
MODEL BLEND CAN BE PREFERRED.
..UPPER TROUGH CROSSING THE PACIFIC NORTHWEST MONDAY
...ENERGY DROPPING DOWN OVER THE NORTHERN PLAINS/MIDWEST FOR
TUESDAY/WEDNESDAY...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z NAM/GFS AND 12Z ECMWF
CONFIDENCE: AVERAGE
AN UPPER TROUGH WILL CROSS IN THROUGH THE PACIFIC NORTHWEST ON
MONDAY AND CROSS FAR SOUTHWEST CANADA BEFORE THEN DROPPING
SOUTHEAST AND DIGGING ACROSS THE NORTHERN PLAINS AND MIDWEST
TUESDAY AND WEDNESDAY. THE 12Z UKMET GRADUALLY BECOMES A WEAKER
AND SOMEWHAT MORE PROGRESSIVE OUTLIER WITH THE ENERGY. MEANWHILE,
THE 12Z CMC DOES THE OPPOSITE AND BECOMES A SLOWER AND DEEPER
OUTLIER. THE 00Z NAM/GFS AND 12Z ECMWF ARE ALL WELL CLUSTERED IN
BETWEEN THESE CAMPS, AND THUS A BLEND OF THESE SOLUTIONS WILL BE
PREFERRED.
..SOUTHERN STREAM TROUGH MOVING INTO CA BY WEDNESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS ARE IN VERY GOOD AGREEMENT WITH THIS ENERGY, AND A
GENERAL MODEL BLEND WILL BE PREFERRED.
..UPPER TROUGH APPROACHING THE PACIFIC NORTHWEST WEDNESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-CMC BLEND
CONFIDENCE: ABOVE AVERAGE
A RELATIVELY DEEP TROUGH WILL BE APPROACHING THE PACIFIC NORTHWEST
BY LATE WEDNESDAY AND THE MODELS ARE OVERALL IN VERY GOOD
AGREEMENT WITH THEIR TIMING AND DEPTH. HOWEVER, THE 12Z CMC IS
PERHAPS A TAD TOO SLOW BY THURSDAY AS THE ENERGY BEGINS TO ADVANCE
INLAND. THEREFORE, A NON-CMC BLEND WILL BE PREFERRED WITH THIS
NEXT TROUGH.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
THIS PRODUCT WILL TERMINATE AUGUST 15, 2020:
WWW.WEATHER.GOV/MEDIA/NOTIFICATION/PDF2/SCN20-58PMDHMD_TERMINATION.
ORRISON
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