632
FXUS10 KWNH 101646
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1245 PM EDT THU OCT 10 2019
VALID OCT 10/1200 UTC THRU OCT 14/0000 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z MODEL EVALUATION WITH LATEST PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..DEEP CLOSED LOW NEAR THE 40N/70W BENCHMARK
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL BLEND
CONFIDENCE: AVERAGE
A DEEP AREA OF LOW PRESSURE SITUATED JUST SOUTHEAST OF THE 40N/70W
BENCHMARK HAS GENERALLY LEVELED OFF IN INTENSITY AND IS FORECAST
TO MAKE A SLOW COUNTER-CLOCKWISE LOOP OVER THE NEXT COUPLE OF DAYS
BEFORE TRACKING FARTHER OUT TO SEA. THIS STORM IS BLOCKED BY A
LARGE LOW TO MID-LEVEL HIGH OVER EASTERN CANADA AND PART OF A REX
BLOCK PATTERN. THE 00Z ECMWF AND TO SOME EXTENT THE 00Z CMC
SOLUTIONS ARE A BIT SLOWER THAN THE MODEL CONSENSUS WITH THE
CYCLONIC LOOP THAT TAKES PLACE, AND ULTIMATELY SLOWER TO ADVANCE
THE SYSTEM EAST AND OUT TO SEA. THE 12Z NAM/GFS AND 00Z UKMET
SOLUTIONS ARE GENERALLY THE FASTEST TO DO THIS. THE ENSEMBLE MEANS
PER THE 00Z ECENS MEAN AND 06Z GEFS MEAN ARE SUPPORTIVE OF THEIR
DETERMINISTIC COUNTERPARTS. A COMPROMISE BETWEEN CAMPS WILL BE
PREFERRED AT THIS POINT, AND A GENERAL MODEL BLEND SHOULD SUFFICE.
..DEEP PLAINS/UPPER MIDWEST CYCLONE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND...LED BY THE 12Z GFS/00Z ECMWF
CONFIDENCE: ABOVE AVERAGE
A STRONG DEEP LAYER TROUGH AND ASSOCIATED CLOSED LOW OVER THE
NORTHERN ROCKIES WILL BE ADVANCING EAST THIS AFTERNOON ACROSS THE
HIGH PLAINS AND WILL CONTINUE TO DEEPEN TONIGHT THROUGH FRIDAY AS
THE SYSTEM PIVOTS ACROSS THE UPPER MIDWEST. THE MODELS ARE IN GOOD
AGREEMENT OVERALL, BUT THE 00Z ECMWF AND 00Z CMC ON FRIDAY BOTH
TEND TO CYCLONICALLY PIVOT THEIR STRONG LOW CENTERS A BIT FARTHER
BACK TO THE WEST AND NORTHWEST ACROSS AREAS OF NORTHWEST MN VERSUS
THE 12Z NAM/GFS AND 00Z UKMET WHICH KEEP LOW PRESSURE A BIT
FARTHER EAST BY COMPARISON. THE ENSEMBLE MEANS ARE SPLIT ON THIS
AS THE 00Z ECENS MEAN SUPPORTS THE ECMWF/CMC CLUSTER, AND THE 06Z
GEFS MEAN SUPPORTS THE NAM/GFS/UKMET CLUSTER. THE 12Z NAM IS ALSO
SEEN AS BEING PERHAPS A BIT TOO STRONG/DEEP WITH ITS MID-LEVEL LOW
CENTER. MEANWHILE, A VERY STRONG COLD FRONT WILL ADVANCE QUICKLY
EAST ACROSS THE LOWER/MID-MS VALLEY AND OH/TN VALLEYS BY LATE
FRIDAY, BEFORE THEN REACHING THE EAST COAST ON SATURDAY. THE 00Z
UKMET IS SEEN AS BEING A TAD SLOW WITH THE COLD FRONT TIMING
VERSUS THE REMAINING GUIDANCE. REGARDING THE DEEP CLOSED LOW OVER
THE UPPER MIDWEST, A PRONOUNCED WEAKENING TREND IS EXPECTED ON
SATURDAY AS THE SYSTEM BECOMES VERTICALLY STACKED. ALL OF THE
MODELS SHOW GOOD AGREEMENT ON THE WEAKENING TREND AT THIS POINT,
AND TAKE THE SYSTEM GRADUALLY ACROSS THE UPPER GREAT LAKES AND
INTO ONTARIO THROUGH SUNDAY. THE PREFERENCE AT THIS POINT WILL BE
A MULTI-MODEL CONSENSUS LED BY THE 12Z GFS AND 00Z ECMWF.
..WESTERN U.S.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-CMC BLEND
CONFIDENCE: ABOVE AVERAGE
A PROGRESSIVE SHORTWAVE TROUGH WILL ADVANCE INLAND FROM THE
PACIFIC OCEAN ON SUNDAY AND ADVANCE INTO THE GREAT BASIN. THE
MODELS SHOW GOOD TIMING AND DEPTH AGREEMENT, BUT THE 00Z CMC
APPEARS TO BE SOMEWHAT OF A PROGRESSIVE OUTLIER BY THE END OF THE
PERIOD. THE REMAINING DETERMINISTIC GUIDANCE AND ENSEMBLE MEANS
FAVOR GOING WITH A NON-CMC BLEND, AND THAT WILL BE THE PREFERENCE.
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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