Prognostic Meteorological Discussion
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000
FXUS10 KWNH 311850
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
249 PM EDT TUE MAY 31 2016

VALID MAY 31/1200 UTC THRU JUN 04/0000 UTC

...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...

12Z MODEL EVALUATION...INCLUDING THE NAM/GFS/UKMET/CMC AND ECMWF

...POST-TROPICAL CYCLONE BONNIE...

PREFERENCE: BLEND OF THE 12Z GFS AND 12Z ECMWF
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

POST-TROPICAL CYCLONE BONNIE IS JUST EAST OF THE SOUTH CAROLINA
COAST AS OF 12Z THIS MORNING...AND THE LATEST GUIDANCE IS IN GOOD
AGREEMENT ON A SLOW NORTHEAST DRIFT OVER THE NEXT 2 TO 3 DAYS THAT
WILL ALLOW IT TO MOVE JUST EAST OF THE NC OUTER BANKS. THE 12Z NAM
AND 12Z GFS ARE A BIT FARTHER LEFT WITH THE TRACK AND TAKE BONNIE
BACK INLAND OVER EASTERN NC...WHEREAS THE 12Z UKMET AND 12Z CMC
ARE FARTHER EAST AND JUST EAST OF THE OUTER BANKS. THE 12Z ECMWF
HAS COMING A BIT FARTHER LEFT...AND IS NOW VERY CLOSE TO THE 12Z
GFS. BASED ON THE MODEL CLUSTERING AND TRENDS...THE RECOMMENDATION
IS FOR A TRACK A TAD LEFT OF THE PREVIOUS PREFERENCE...WHICH WILL
TAKE BONNIE NEAR OR JUST WEST OF THE OUTER BANKS...AND THIS WOULD
BE CONSISTENT WITH A BLEND OF THE GFS AND ECMWF.


...SHORTWAVE CLIPPING NEW ENGLAND THROUGH EARLY WED...
...ASSOCIATED FRONTAL CROSSING THE NORTHEAST...

PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE MODELS ARE IN GOOD AGREEMENT WITH RESPECT TO TIMING AND DEPTH
OF THIS SYSTEM...SO WILL PREFER A GENERAL MODEL COMPROMISE.


...DEEP LAYER LOW CENTER CROSSING THE NORTHERN PLAINS...
...ENERGY LIFTING INTO ONTARIO THROUGH THURS...

PREFERENCE: NON-GFS CONSENSUS
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

THE MODELS ARE IN GOOD AGREEMENT IN TAKING THE UPPER LOW OVER THE
NORTHERN PLAINS GRADUALLY OFF TO THE EAST-NORTHEAST OVER THE NEXT
DAY OR SO WHICH WILL ALLOW SURFACE LOW PRESSURE TO LIFT INTO
ONTARIO BY THURS. THE SYSTEM SHOULD GRADUALLY WEAKEN THROUGH THE
PERIOD...BUT THE 12Z GFS TENDS TO HANG ONTO A STRONGER TROUGH/LOW
CENTER THAT IS NOT WELL SUPPORTED BY THE OTHER DETERMINISTIC
GUIDANCE OR THE ENSEMBLE MEANS. WILL LEAN TOWARD A NON-GFS
CONSENSUS GIVEN GOOD MODEL CLUSTERING SEEN AWAY FROM THE GFS
SOLUTION.


...CLOSED LOW OVER THE SOUTHWEST ADVANCING EAST INTO TEXAS BY
THURS...

PREFERENCE: BLEND OF THE 12Z GFS AND 12Z ECMWF
CONFIDENCE: AVERAGE

ALL OF THE MODELS TAKE THE CLOSED LOW OVER THE SOUTHWEST GRADUALLY
EAST OVER THE NEXT COUPLE OF DAYS...AND REACHING OUT ACROSS TX FOR
THURS AND FRI. THE 12Z NAM DOES GENERALLY APPEAR TO BE A TAD TOO
DEEP AS THE SYSTEM REACHES TX...AND BY THE END OF THE PERIOD THE
12Z UKMET APPEARS TO BE TOO SLOW. THE REMAINING MODELS ARE A
LITTLE FASTER...BUT THE 12Z ECMWF AND 12Z CMC BY THE END OF THE
PERIOD ARE SEEN AS PLACING THEIR CLOSED LOW CENTER A BIT NORTH OF
THE 12Z NAM AND 12Z GFS SOLUTIONS. THE LATEST ECENS MEAN STRONGLY
SUPPORTS THE ECMWF/CMC SOLUTIONS BY THE END OF THE PERIOD...WITH
THE GEFS MEAN FAVORING THE NCEP SOLUTIONS. THE PREFERENCE IS TO
SPLIT THE DIFFERENCE BETWEEN THE ECMWF AND GFS LED CAMPS...WHICH
WOULD MOST LIKELY EQUATE TO A SOMEWHAT MORE PROGRESSIVE UKMET
SOLUTION. PLEASE CONSULT THE LATEST QPFPFD FOR MORE DETAILS
CONCERNING THE QPF PREFERENCES/FORECAST...AS THEIR ARE SIGNIFICANT
QPF DIFFERENCES NOTED FOR THIS PERIOD.


...SHORTWAVE TROUGH DIGGING DOWN ACROSS THE NORTHERN PLAINS ON
FRI...

PREFERENCE: BLEND OF THE 12Z GFS AND 12Z ECMWF
CONFIDENCE: AVERAGE

THE MODELS INDICATE A SHORTWAVE TROUGH DIGGING SOUTHEAST ACROSS
THE NORTHERN PLAINS BY FRI WHICH WILL BE ACCOMPANIED BY A WEAK
AREA OF LOW PRESSURE AND A FRONTAL ZONE. THE 12Z GFS AND 12Z ECMWF
ARE BIT A TAD SLOWER AND DEEPER THAN THE MULTI-MODEL
CONSENSUS...WITH THE 12Z NAM THE WEAKEST AND A BIT MORE
PROGRESSIVE. THE 12Z UKMET AND 12Z CMC SPLIT THE DIFFERENCE
BETWEEN CAMPS. GIVEN SOME TRENDS IN THE GUIDANCE FOR THIS
SHORTWAVE TO BECOME MORE AMPLIFIED GIVEN THE UPSTREAM RIDGE...THE
SOMEWHAT SLOWER/STRONGER GFS/ECMWF SOLUTIONS SEEM CERTAINLY
PLAUSIBLE...AND SINCE THE ECMWF TRENDED TOWARD THE GFS
SOLUTION...A BLEND OF THE GFS AND ECMWF WILL BE PREFERRED AT THIS
TIME.

...MODEL TREND GRAPHICS 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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