993
FXUS10 KWNH 100504
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
103 AM EDT SUN MAY 10 2020
VALID MAY 10/0000 UTC THRU MAY 13/1200 UTC
...SEE NOUS42 KWNO (ADMSDM) FOR THE STATUS OF THE UPPER AIR
INGEST...
00Z MODEL EVALUATION INCLUDING LATEST PREFERENCES AND CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
..EXITING DEEP LAYER CYCLONE IMPACTING THE NORTHEAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE
THE MODELS ARE IN VERY GOOD AGREEMENT WITH THE DETAILS OF THE DEEP
LAYER CYCLONE CURRENTLY IMPACTING THE NORTHEAST, WHICH WILL BE
LIFTING OFF TO THE NORTHEAST ACROSS THE CANADIAN MARITIMES THROUGH
TONIGHT AND SUNDAY. A GENERAL MODEL BLEND IS PREFERRED.
...COMPACT SHORTWAVES/SURFACE LOW IMPACTING THE NORTHERN PLAINS
AND MIDWEST THIS WEEKEND...
...ENERGY AMPLIFYING FROM THE OH VALLEY TO THE NORTHEAST MON AND
TUES...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
THE GUIDANCE TAKES THE VIGOROUS COMPACT SHORTWAVE AND ASSOCIATED
SURFACE LOW OVER THE NORTHERN PLAINS SOUTHEASTWARD ACROSS THE
MIDWEST GOING THROUGH SUNDAY. ON MONDAY THIS LEAD ENERGY AND A
FAST-MOVING SECONDARY SHORTWAVE IN ITS WAKE WILL CONSOLIDATE AND
TRANSIT THE OH VALLEY. AS THE ENERGY ROUNDS THE BASE OF THE LARGER
SCALE TROUGHING THAT WILL BE PERSISTING FROM THE GREAT LAKES
REGION INTO MUCH OF SOUTH-CENTRAL AND SOUTHEAST CANADA, THIS OH
VALLEY ENERGY SHOULD AMPLIFY, AND BY TUESDAY ALL OF THE MODELS
SUPPORT THE IDEA OF A NEGATIVELY TILTING SHORTWAVE AND POSSIBLE
CLOSED MID-LEVEL LOW CROSSING NEW ENGLAND ALONG WITH AN
INTENSIFYING SURFACE LOW CENTER.
EARLY TRENDS IN THE 00Z MODELS SUGGEST MODELS ARE MOVING INTO
BETTER AGREEMENT WITH THEIR HANDLING OF THIS CONSOLIDATING
SHORTWAVE MOVING FROM THE OHIO VALLEY INTO THE NORTHEAST ON
MONDAY. THE NAM WHICH HAD SHOWN A MORE AMPLIFIED SHORTWAVE MOVING
FROM CANADA INTO THE NORTHEAST LATE TUESDAY, HAS BACKED AWAY SOME
FROM THAT SOLUTION WITH ITS 00Z RUN - PUTTING INTO BETTER
AGREEMENT WITH THE OVERALL MODEL CONSENSUS. THE GFS HAS ALSO
TRENDED TOWARD THE CONSENSUS AS WELL. WHILE ITS 12Z RUN WAS
FASTER THAN MOST MODELS LIFTING THE SHORTWAVE ACROSS THE NORTHEAST
LATE MONDAY INTO EARLY TUESDAY, THE 00Z GFS IS NOW SLOWER. THIS
PUTS MOST OF THE DETERMINISTIC GUIDANCE INTO FAIRLY GOOD AGREEMENT
THROUGH 12Z TUESDAY AS THE LEADING FEATURE MOVES FROM NORTHERN NEW
ENGLAND INTO THE CANADIAN MARITIMES.
..SHORTWAVE ENERGY CROSSING THE SOUTHWEST THIS WEEKEND
..ENERGY SHEARING ACROSS THE SOUTHERN PLAINS BY TUES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: AVERAGE
THE MODELS SHOW A WEAK SHORTWAVE CROSSING THE DESERT SOUTHWEST ON
SUNDAY. THIS ENERGY IS THEN EXPECTED TO GRADUALLY SHEAR OFF TO THE
EAST AND REACH THE SOUTHERN PLAINS BY TUESDAY AND THE LOWER
MISSISSIPPI VALLEY BY EARLY WEDNESDAY. WHILE DIFFERENCES IN THE
FINER DETAILS PERSIST - WITH LOW PREDICTABILITY REGARDING THE
TIMING/AMPLIFICATION OF THE EMBEDDED ENERGY MOVING ACROSS THE
SOUTHERN PLAINS - OVERALL SPREAD WITH RESPECT TO THE LARGER SCALE
PATTERN IS MODEST.
...UPPER TROUGH/CLOSED LOW LIFTING ALONG THE NORTHWEST COAST
MON-TUE...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 00Z GFS AND 12Z ECMWF
CONFIDENCE: SLIGHTLY ABOVE AVERAGE
AN UPPER TROUGH AND ASSOCIATED CLOSED LOW WILL BE APPROACHING THE
WEST COAST BY TUESDAY AS THE LARGER SCALE BLOCKING PATTERN ACROSS
WESTERN NORTH AMERICA BEGINS TO BREAK DOWN. THE NAM REMAINS THE
GENERAL OUTLIER HERE - BRINGING AN UPPER LOW OVER WESTERN CANADA
FARTHER WEST, DRAWING THE LOW OFF OF THE COAST FARTHER EAST THAN
THE MODEL CONSENSUS. NEVERTHELESS, ALL OF THE MODELS INCREASE THE
ONSHORE FLOW INTO THE WEST COAST, ESPECIALLY FROM NORTHERN CA TO
THE PACIFIC NORTHWEST AS SURFACE LOW PRESSURE LIFTS NORTHEAST UP
OFF THE COAST. BASED ON VERY GOOD MODEL MASS FIELD CLUSTERING AND
ENSEMBLE SUPPORT, A BLEND OF THE GFS AND 12Z ECMWF REMAINS
PREFERRED AT THIS POINT.
MODEL TRENDS AT WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML
500 MB FORECASTS AT WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML
PEREIRA/ORRISON
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