Prognostic Meteorological Discussion
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000
FXUS10 KWNH 021652
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1252 PM EDT MON MAY 02 2016

VALID MAY 02/1200 UTC THRU MAY 06/0000 UTC

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

12Z NAM/GFS EVALUATION...INCLUDING PRELIMINARY PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


COLD FRONT SLOWLY MOVING ACROSS THE EAST COAST STATES THROUGH WED
SURFACE LOW ALONG THE FRONT...DEVELOPING NEWD FROM THE MID-ATLANTIC
  COAST ON WED
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 00Z ECMWF/UKMET BLEND
CONFIDENCE: SLIGHTLY BELOW AVERAGE

WHILE THERE IS GOOD AGREEMENT WITH THE FRONTAL PROGRESSION THROUGH
THE MID-ATLANTIC REGION AND SOUTHEAST...THERE ARE LARGE
DIFFERENCES WITH A SURFACE LOW FORECAST TO TRACK NEWD FROM THE
MID-ATLANTIC COAST ON WED/WED NIGHT AS SEEN IN THE LATEST
DETERMINISTIC AND ENSEMBLE GUIDANCE.

THE 12Z GFS IS ON THE STRONGER SIDE OF THE DETERMINISTIC SPREAD
AND THE 12Z NAM SHOWS A DIFFERENT SURFACE PATTERN OFFSHORE WITH
THE FRONT. THE 00Z ECMWF/UKMET ARE IN THE MIDDLE OF THE SPREAD AND
REPRESENT A COMPROMISE POSITION BUT THE ENSEMBLE SCATTER LOW PLOTS
VARY WIDELY VALID 12Z/05 FROM THE OUTER BANKS OF NORTH CAROLINA TO
SRN NOVA SCOTIA REDUCING CONFIDENCE A BIT.


CLOSED LOW DROPPING SOUTH ACROSS THE GREAT LAKES WED...REACHING THE
  MID-ATLANTIC STATES THU
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z NAM/00Z ECMWF MEAN BLEND
CONFIDENCE: AVERAGE

THE ENSEMBLES SHOW A POSITION A BIT NORTH OF THE 12Z NAM/GFS/ECMWF
WITH THE 500 MB LOW BUT TRENDS HAVE BEEN SOUTH. THE ENSEMBLES
CLUSTER A SURFACE LOW ABOUT 100 MILES EAST OF THE SRN DELMARVA
PENINSULA ON 00Z/06 WHICH IS NEAR THE 12Z NAM AND NEAR THE 00Z
ECMWF MEAN. 700-500 MB HEIGHT FIELDS ARE RATHER SIMILAR TO EACH
OTHER IN THE LATEST DETERMINISTIC GUIDANCE.


COLD FRONT MOVING INTO THE PACIFIC NORTHWEST ON TUE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON 00Z UKMET BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

THE 00Z UKMET DRAGS THE UPPER TROUGH SLOWER ACROSS BRITISH
COLUMBIA ON WED...BUT OTHERWISE THE MODELS ARE IN GOOD AGREEMENT
WITH THIS SYSTEM.


CLOSED LOW REACHING THE CALIFORNIA COAST WED/THU
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: AVERAGE

NO SIGNIFICANT MODEL DIFFERENCES WERE NOTED WITH THIS SYSTEM.


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

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


OTTO

$$




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