601
FXUS10 KWNH 021845
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
244 PM EDT FRI AUG 02 2019
VALID AUG 02/1200 UTC THRU AUG 06/0000 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z MODEL EVALUATION AND PREFERENCES/CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..CENTRAL/SOUTHERN PLAINS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS SHOW MID-LEVEL SHORTWAVE ENERGY DROPPING DOWN ACROSS
EASTERN KS TONIGHT AND EARLY SATURDAY BEFORE THEN ADVANCING SOUTH
DOWN ACROSS THE SOUTHERN PLAINS TOWARD THE RED RIVER VALLEY OF THE
SOUTH. THE MODELS HAVE COME INTO BETTER AGREEMENT WITH THEIR
TIMING AND STRENGTH, AND SO A GENERAL MODEL BLEND WILL BE FAVORED
WITH THIS ENERGY.
..OH VALLEY/MID-ATLANTIC/NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
AN UPPER TROUGH WILL BE SWINGING ACROSS THE NORTHEAST U.S. THIS
WEEKEND AS A DEEPENING CLOSED LOW IMPACTS PORTIONS OF SOUTHEAST
CANADA. MEANWHILE, THE GUIDANCE SUPPORTS A SHORTWAVE IMPULSE
DROPPING SOUTHEAST FROM THE GREAT LAKES REGION AND CROSSING THE
UPPER OH VALLEY AND THE MID-ATLANTIC REGION GOING THROUGH MONDAY.
THE 12Z UKMET MAY BE TAD TOO WEAK WITH THIS SHORTWAVE, BUT THE
GUIDANCE IS OTHERWISE IN GOOD AGREEMENT WITH THE TIMING AND DEPTH
OF TH ENERGY. A GENERAL MODEL BLEND WILL BE PREFERRED.
..PACIFIC NORTHWEST/SOUTHWEST CANADA
..UPPER MIDWEST BY MONDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND...THROUGH 60 HOURS
NON-NAM BLEND...AFTER 60 HOURS
CONFIDENCE: ABOVE AVERAGE
THE GUIDANCE AGREES IN TAKING A POSITIVELY TILTED LONGWAVE TROUGH
ACROSS SOUTHWEST BRITISH COLUMBIA, VANCOUVER ISLAND, AND OFF THE
NORTHWEST COAST AND MOVING THE WAVE NORTHEAST INTO CENTRAL CANADA
OVER THE WEEKEND. THE ENERGY WILL THEN BEGIN TO DIG A BIT TO THE
SOUTHEAST AND CROSS INTO THE UPPER MIDWEST ON MONDAY. THE GUIDANCE
IS IN GOOD AGREEMENT WITH THE OVERALL EVOLUTION OF THIS ENERGY
THROUGH THE PERIOD WITH EXCEPTION TO THE 12Z NAM WHICH BEGINS TO
OUTRUN THE GLOBAL MODELS WITH THE TIMING OF ITS CLOSED LOW PASSING
JUST SOUTHWEST OF HUDSON BAY BY THE END OF THE PERIOD. A GENERAL
MODEL BLEND THROUGH 60 HOURS SHOULD SUFFICE, FOLLOWED BY A NON-NAM
BLEND THEREAFTER.
..UPPER LOW/TROUGH OFF THE PACIFIC NORTHWEST ON SUNDAY/MONDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS TAKE A PORTION OF THE ENERGY TRAVERSING SOUTHWEST
CANADA AND PINCH OFF A NEW TROUGH/CLOSED LOW JUST OFFSHORE OF
WA/OR BY SUNDAY. THE MODELS ARE IN REASONABLY GOOD AGREEMENT WITH
THEIR POSITIONING AND DEPTH OF THE SYSTEM, AND THUS A GENERAL
MODEL BLEND WILL BE PREFERRED.
..UPPER TROUGH OVER THE GULF COAST/SOUTHEAST
..SURFACE LOW DEVELOPMENT NEAR THE SOUTHEAST COAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
A BROAD UPPER TROUGH OVER THE GULF COAST STATES AND ADJACENT AREAS
OF THE TN VALLEY AND THE SOUTHEAST WILL GENERALLY REMAIN IN PLACE
THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. THERE IS MINIMAL
SPREAD WITH THE LARGER SCALE DETAILS OF THE TROUGH, AND SO A
GENERAL MODEL BLEND WILL BE PREFERRED WITH THIS ENERGY.
REGARDING THE SURFACE TROUGH LIFTING UP OFF THE SOUTHEAST
COASTLINE, THE MODELS STILL FAVOR SOME WEAK SURFACE LOW
DEVELOPMENT ALONG IT AS THE ENERGY BEGINS TO TURN NORTHEAST AND
OUT TO SEA TO THE EAST OF THE NC OUTER BANKS ON SUNDAY. THE 12Z
NAM IS THE STRONGEST SOLUTION WITH THE 12Z CMC SOLUTION NOW THE
WEAKEST. A GENERAL MODEL BLEND OF THE GUIDANCE SHOULD RESOLVE THE
DIFFERENCES SEEN IN THE STRENGTH OF THE LOW FOR THIS PERIOD.
MODEL TRENDS AT WWW.WPC.NOAA.GOV/HTML/MODEL2.HTML
500 MB FORECASTS AT WWW.WPC.NOAA.GOV/H5PREF/H5PREF.SHTML
ORRISON
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