FXUS10 KWNH 090704
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
203 AM EST MON NOV 09 2015

VALID NOV 09/0000 UTC THRU NOV 12/1200 UTC

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

...0Z GFS/NAM/ECMWF/GEM/UKMET EVALUATION AND FINAL PREFERENCES...

...DEVELOPING CLOSED LOW OVER THE MID MS VALLEY...
...MOVING ACROSS THE OH VALLEY AND NORTHEAST...
...LOW PRESSURE OVER THE NORTHEAST GULF OF MEXICO...
...LIFTING NORTHEAST TO THE MID-ATLANTIC/NEW ENGLAND...

PREFERENCE: NON NAM CONSENSUS
CONFIDENCE: ABOVE AVERAGE

A CLOSED LOW CENTER CURRENTLY OVER KS/OK WILL EJECT EAST-NORTHEAST
ACROSS THE OH VALLEY AND INTO THE NORTHEAST TUES AND WED WHILE
GRADUALLY WEAKENING. THIS ENERGY WILL PLAY A ROLE IN THE EVOLUTION
OF LOW PRESSURE EJECTING NORTHEAST OUT OF THE NORTHERN GULF OF
MEXICO ...WHICH IS EXPECTED TO LIFT NORTHEAST ACROSS THE SOUTHEAST
COASTAL PLAIN AND ESSENTIALLY REDEVELOP ALONG THE MID-ATLANTIC
COAST TUESDAY BEFORE LIFTING INTO SOUTHERN NEW ENGLAND BY WED. THE
0Z NAM REMAINS AN OUTLIER WITH A MORE PROGRESSIVE AND FURTHER WEST
TRACK OF THE DEVELOPING COASTAL LOW. THERE IS PRETTY GOOD
CLUSTERING AMONG THE 0Z GFS AND 12Z ECMWF/GEM/UKMET THROUGH 12Z
WEDNESDAY. THEREAFTER THE UKMET SEEMS TO BECOME A BIT TOO
PROGRESSIVE...WITH BETTER AGREEMENT BETWEEN THE GEM/ECMWF/GFS.
WHILE SOME MINOR DIFFERENCES EXIST AMONG THESE THREE...THERE IS NO
STRONG SIGNAL TO PREFER ONE OVER ANOTHER AND THUS WILL PREFER A
GEM/ECMWF/GFS CONSENSUS.

FINAL UPDATE: IN GENERAL THE 0Z ECMWF/UKMET/GEM HANDLE THE
EVOLUTION OF THIS SYSTEM PRETTY SIMILAR. THUS AT THIS POINT A NON
NAM BLEND CAN BE CONSIDERED A PROBABLE OUTCOME...WITH CONVECTIVE
FEEDBACK ISSUES CONTINUING TO IMPACT THE NAM SOLUTION.


...DEEP UPPER TROUGH CROSSING THE WESTERN U.S. AND EJECTING TOWARD
THE MIDWEST...
...STRENGTHENING SURFACE CYCLONE ACROSS THE CENTRAL
PLAINS/MIDWEST...

PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: ABOVE AVERAGE

A DEEP UPPER TROUGH MOVING INTO THE WEST COAST WILL EJECT
VIGOROUSLY INTO THE CENTRAL PLAINS AND THEN THE MIDWEST BY
WEDNESDAY. A STRONG AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP
OVER THE CO HIGH PLAINS LATE TUESDAY...MOVING ACROSS KS/NE ON
WEDNESDAY...AND THEN NORTHEAST TOWARDS IA/MN/WI ON WEDNESDAY
NIGHT. THE MODELS ON THE LARGER SCALE CONTINUE TO BE IN VERY GOOD
AGREEMENT...WITH JUST SOME RELATIVELY MINOR LOW TRACK AND TIMING
DIFFERENCES. THE 0Z GFS IS THE THE MOST PROGRESSIVE AND FURTHEST
SOUTHEAST WITH THE LOW TRACK...WITH THE 0Z NAM/12Z ECMWF SLOWEST
AND FURTHEST NORTHWEST...AND THE UKMET/GEM IN BETWEEN. THE GFS IS
PROBABLY A BIT TOO FAR SOUTHEAST GIVEN RECENT TRENDS...BUT IT IS
QUITE POSSIBLE THE ECMWF IS TOO FAR NORTHWEST. THUS A CONSENSUS
SEEMS TO CONTINUE TO REPRESENT THE MOST LIKELY SCENARIO.

FINAL UPDATE: ONLY MINOR CHANGES SEEN IN THE 0Z
ECMWF/GEM/UKMET...WITH JUST A SLIGHTLY FURTHER SOUTHEAST/MORE
PROGRESSIVE LOW TRACK. THUS THE 0Z NAM IS NOW THE FURTHEST
NORTHWEST/SLOWEST...BUT IT IS ONLY A MINOR DIFFERENCE AND STILL
APPEARS WITHIN THE ENVELOPE OF POSSIBILITIES. THUS WILL CONTINUE
WITH A GENERAL MODEL BLEND WITH THIS SYSTEM.


...NORTHERN STREAM SYSTEM MIGRATING THROUGH THE DAKOTAS...

PREFERENCE: 0Z GFS/NAM/ECMWF BLEND
CONFIDENCE: ABOVE AVERAGE

A MUCH WEAKER NORTHERN STREAM FEATURE MAKES ITS WAY THROUGH THE
DAKOTAS BY MIDDAY TUES. THE 12Z GEM/UKMET BOTH APPEAR TO BE A BIT
TOO DEEP WITH THIS SYSTEM. SOMETHING CLOSER TO THE 0Z GFS/NAM AND
12Z ECMWF IS PREFERRED AT THIS TIME.

FINAL UPDATE: THE 0Z GEM STILL APPEARS TO BE A BIT STRONG WITH
THIS SYSTEM...WITH A NAM/GFS/ECMWF CONSENSUS STILL PREFERRED.


...PROGRESSIVE SHORTWAVE REACHING THE PACIFIC NORTHWEST BY WED...

PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: ABOVE AVERAGE

A RATHER PROGRESSIVE SHORTWAVE AND ASSOCIATED COLD FRONT WILL
CROSS THE NORTHWEST ON WEDNESDAY...MOVING TOWARDS THE NORTHERN
PLAINS BY 12Z THURSDAY. OVERALL THE 0Z GFS/NAM AND 12Z
ECMWF/GEM/UKMET ALL HANDLE THIS SYSTEM PRETTY SIMILARLY THROUGH
THURSDAY MORNING...WITH A GENERAL CONSENSUS LOOKING GOOD.

FINAL UPDATE: WHILE SOME DIFFERENCES DO BEGIN TO EMERGE WITH THE
HANDLING OF THIS SYSTEM BY LATER WEDNESDAY...STILL PREFER A
GENERAL MODEL COMPROMISE GIVEN THE RELATIVELY MINOR DIFFERENCES
AND ALL SOLUTIONS SEEMING TO FALL WITHIN THE REASONABLE RANGE OF
POSSIBILITIES.


...MODEL TREND GRAPHICS AT
www.wpc.ncep.noaa.gov/html/model2.shtml...

...500 MB FORECASTS AT
www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml...

CHENARD

$$