777
FXUS10 KWNH 101706
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
105 PM EDT FRI APR 10 2020
VALID APR 10/1200 UTC THRU APR 14/0000 UTC
...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...
12Z MODEL EVALUATION...WITH PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..DEEP CYCLONE EXITING THE NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE ANOMALOUSLY DEEP CLOSED LOW IMPACTING THE NORTHEAST TODAY WILL
BE EJECTING NORTHEAST ACROSS SOUTHEAST CANADA TONIGHT AND
SATURDAY. THE GUIDANCE SHOWS VERY GOOD LARGE SCALE AGREEMENT WITH
THE MASS-FIELD EVOLUTION, SO A GENERAL MODEL BLEND WILL BE
PREFERRED AS THIS SYSTEM BEGINS TO EXIT.
..CLOSED LOW EXITING THE SOUTHWEST
..ENERGY EJECTING TOWARD THE LOWER MS VALLEY BY SUNDAY
..POWERFUL SURFACE LOW OVER THE GREAT LAKES BY MONDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z GFS/00Z UKMET/00Z ECMWF AND ECENS/GEFS BLEND
CONFIDENCE: AVERAGE...THROUGH 60 HOURS
BECOMING BELOW AVERAGE...AFTER 60 HOURS
THE LARGE, SLOW-MOVING CUT-OFF SOUTHERN STREAM LOW OVER SOUTHERN
CALIFORNIA WILL GRADUALLY MOVE TOWARD SOUTHERN AZ/NM ON SATURDAY
AND THEN OPEN UP INTO A PROGRESSIVE SHORTWAVE ACROSS THE SOUTHERN
PLAINS BY EARLY SUNDAY. BY LATE SUNDAY, THIS ENERGY WILL BEGIN TO
TAKE ON A NEGATIVE TILT OVER THE LOWER MS VALLEY AND QUICKLY REACH
THE OH VALLEY BY EARLY MONDAY. THE ENERGY COUPLED WITH INCREASING
INFLUENCE FROM A STRONG NORTHERN STREAM TROUGH AMPLIFYING OVER THE
UPPER MIDWEST SUNDAY AND MONDAY WILL LEAD THE WAY FOR A POWERFUL
SURFACE CYCLONE TO LIFT OVER WESTERN AND NORTHERN PARTS OF LOWER
MI ON MONDAY. THE GUIDANCE HAS GENERALLY COME INTO BETTER
AGREEMENT WITH THE EVOLUTION OF THE SHORTWAVE ENERGY ACROSS THE
SOUTH, WITH MULTI-CYCLE TRENDS OF THE GFS COMING IN SLOWER AND
TOWARD THE NON-NCEP MODEL CAMP. TODAY'S DIFFERENCES ARE MUCH MORE
FOCUSED ON THE OH VALLEY AND GREAT LAKES REGION. THE 12Z NAM ENDS
UP WITH A SOMEWHAT FASTER SHORTWAVE PROGRESSION UP NORTH ACROSS
THE OH VALLEY INTO LOWER MI, AND A LOW TRACK ON THE LEFT SIDE OF
THE DETERMINISTIC MODEL SPREAD. THE 00Z CMC WAS OVERALL THE
BIGGEST OUTLIER SOLUTION WITH A WEAKER AND FARTHER NORTHWEST
SURFACE LOW TRACK ACROSS THE GREAT LAKES. THE 00Z ECENS/CMCE
SUITES AND ESPECIALLY THE 00Z/06Z GEFS SUITES FAVOR OVERALL A
SOLUTION THAT IS QUITE DEEP, BUT WITH A LOW TRACK PERHAPS A TAD
FARTHER EAST OF THE NAM/CMC SOLUTIONS. HAVING SAID THAT, THERE IS
A CAMP OF EC ENSEMBLE MEMBERS THAT DO TAKE THE LOW OFF FARTHER TO
THE NORTHWEST, AND THE KEY FOR THIS TO VERIFY WILL BE THE
INTRUSION OF STRONGER NORTHERN STREAM ENERGY FROM THE UPPER
MIDWEST AND SUBSEQUENT PHASING. CONFIDENCE IS SOMEWHAT LIMITED
LATE IN THE PERIOD AS THERE IS ROOM FOR A SOMEWHAT DEEPER LOW TO
TRACK FARTHER WEST OVER THE GREAT LAKES, BUT BASED ON THE LATEST
CLUSTERING FROM THE 12Z GFS/00Z UKMET AND 00Z ECMWF WHICH IS A TAD
FARTHER EAST, A BLEND OF THESE SOLUTIONS WILL BE PREFERRED, AND IN
CONJUNCTION WITH THE ENSEMBLE MEANS.
..AMPLIFYING UPPER TROUGH OVER THE NORTHERN U.S. BY MONDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS BRING AMPLIFYING SHORTWAVE/JET ENERGY SOUTHEASTWARD
FROM THE SOUTHERN COAST OF AK AND THE ADJACENT YUKON TERRITORY
DOWN ACROSS SOUTHWEST CANADA AND OUT ACROSS THE NORTHERN ROCKIES
AND NORTHERN PLAINS BY SUNDAY. BY MONDAY, THIS ENERGY WILL AMPLIFY
INTO A DEEP LONGWAVE TROUGH OVER THE NORTHERN U.S. THAT WILL
GRADUALLY PHASE WITH THE AFOREMENTIONED SOUTHERN STREAM ENERGY
EJECTING ACROSS THE SOUTH AND LIFTING TOWARD THE GREAT LAKES
REGION. THE MODELS ARE IN GOOD AGREEMENT WITH THE DETAILS OF THE
LONGWAVE TROUGH EVOLUTION. SO, A GENERAL MODEL BLEND WILL BE
PREFERRED WITH THIS.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
ORRISON
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