Prognostic Meteorological Discussion
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FXUS10 KWNH 281851
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
150 PM EST WED JAN 28 2015

VALID JAN 28/1200 UTC THRU FEB 01/0000 UTC

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

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


...SHORTWAVE TROUGHING/ENERGY CROSSING THE CENTRAL
PLAINS/MIDWEST...
...NEGATIVELY TILTING UPPER TROUGH REACHING THE NORTHEAST BY FRI...
...REDEVELOPING COASTAL NEW ENGLAND SURFACE LOW...

PREFERENCE: BLEND OF THE 12Z ECMWF/12Z GEFS MEAN AND 00Z ECENS MEAN
CONFIDENCE: AVERAGE

SHORTWAVE ENERGY CURRENTLY SHEARING OUT OF THE GREAT BASIN IS
EXPECTED TO ADVANCE EAST AND CROSS OUT THROUGH THE CENTRAL PLAINS
AND MIDWEST THROUGH THURS. THE MODELS SHOW GOOD AGREEMENT IN
DEPICTING ADDITIONAL NORTHERN STREAM ENERGY DIGGING IN BEHIND THE
LEAD SHORTWAVE...WITH A COMBINATION OF THE TWO LEADING THE WAY FOR
WHAT SHOULD BE A LARGER SCALE AND NEGATIVELY TILTING TROUGH ACROSS
THE GREAT LAKES/OHIO VALLEY AND NORTHEAST THROUGH FRIDAY. THERE IS
GOOD AGREEMENT IN ENOUGH AMPLIFICATION FOR A MID LEVEL LOW TO
CLOSE OFF OVER SOUTHERN NEW ENGLAND BY FRI NIGHT WHICH WILL MOVE
ACROSS THE GULF OF MAINE ON SAT. THE STRONG HEIGHT FALLS WILL
ALLOW SURFACE LOW PRESSURE TRAVERSING THE MIDWEST AND LOWER GREAT
LAKES REGION TO REDEVELOP JUST OFF SOUTHERN NEW ENGLAND BY MIDDAY
FRI AND THEN INTENSIFY OVER THE GULF MAINE.

THERE IS GOOD AGREEMENT AMONG THE MODELS WITH THE LARGER SCALE
EVOLUTION OF THIS NEXT SYSTEM...BUT THERE ARE SOME TIMING
DIFFERENCES TO NOTE. THE 12Z GFS IS JUST A TAD FASTER THAN THE
GLOBAL MODEL CONSENSUS AS THE ENERGY REACHES THE NORTHEAST...WITH
THE 12Z UKMET JUST A TAD SLOWER. THE 12Z ECMWF AND 12Z GEM ARE IN
BETWEEN CAMPS. THE 12Z NAM TENDS TO BE A BIT FARTHER SOUTH AND A
LITTLE DEEPER THAN THE MULTI-MODEL CONSENSUS. AT THE SURFACE...THE
NAM TENDS TO TAKE ITS SURFACE LOW FARTHEST EAST. THE GFS IS
OVERALL FARTHEST WEST AND TUCKED IN CLOSER TO THE COAST OF MAINE.
THE ECMWF/UKMET AND GEM SPLIT THE DIFFERENCE. THE 12Z GEFS MEAN
SUGGESTS THE DETERMINISTIC GFS IS TUCKED INTO THE MAINE COAST A
LITTLE TOO MUCH...AND LIKE THE ECENS MEAN...FAVORS THE ECMWF
PLACEMENT. THE UKMET AND GEM SUPPORT THIS CONSENSUS. WILL FAVOR A
BLEND OF THE 12Z GEFS MEAN/00Z ECENS MEAN AND 12Z ECMWF AS A
RESULT FOR NOW.


...CLOSED LOW ACROSS THE SOUTHWEST BY THE END OF THE WEEK...

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

THERE IS STILL RELATIVELY MINOR SPREAD IN A SOMEWHAT BROAD UPPER
TROUGH MAKING ITS WAY TOWARD THE WEST COAST. BY FRIDAY...THE
MODELS DEPICT A LARGE UPPER LOW WITH A BIT OF A N/S ELONGATION
STRETCHING FROM THE GREAT BASIN SOUTH INTO THE NORTHERN BAJA
PENINSULA. STRONGER MODEL CLUSTERING OVERALL TENDS TO FAVOR A
BLEND OF THE 12Z GFS AND 12Z ECMWF...WHICH IS SUPPORTED BY THE
LATEST GEFS MEAN AND ECENS MEAN.


...SHORTWAVE TROUGH/COLD FRONT DROPPING DOWN ACROSS THE NORTHERN
PLAINS SAT...

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

THE MODELS DROP NORTHERN STREAM ENERGY ALONG WITH A COLD FRONT
DOWN INTO THE NORTHERN PLAINS REGION BY SAT. THE 12Z GEM IS
NOTABLY MORE AMPLIFIED WITH THE TROUGH THAN THE RELATIVELY FLAT
MULTI-MODEL CONSENSUS. THE STRONGER MODEL CLUSTERING AT THIS POINT
WOULD FAVOR A BLEND OF THE 12Z GFS AND 12Z ECMWF.


...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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