Prognostic Meteorological Discussion
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FXUS10 KWNH 140502
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1201 AM EST SUN FEB 14 2016

VALID FEB 14/0000 UTC THRU FEB 17/1200 UTC

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

00Z GFS/NAM EVALUATION INCLUDING PREFERENCES/CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GFS/NAM INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT
RANGE FORECASTS.


SYSTEM DIGGING SEWD FROM THE NRN PLAINS INTO THE MID MS AND OH
VALLEYS MON/TUES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GFS/ECMWF/EC MEAN COMPROMISE
CONFIDENCE: AVERAGE

THE 00Z GFS HAS TRENDED SLIGHTLY FASTER AND DEEPER WITH S/WV TROF
AND ACCOMPANYING SFC LOW THAT IS FCST TO DIG SEWD INTO THE
MIDWEST/MID MS VALLEY ON TUE MRNG AND IT ALONG WITH THE 12Z EC
REPRESENT A DECENT MIDDLE GROUND BETWEEN THE SLIGHTLY FLATTER NAM
AND DEEPER/FARTHER SOUTH 12Z UKMET.  THE 12Z DETERMINISTIC EC ALSO
MATCHED WELL WITH ITS ENSEMBLE MEAN AND IT ALONG WITH THE GFS
PROVIDE A DECENT COMPROMISE GIVEN THE RATHER LARGE SPREAD IN
ENSEMBLE LOW TRACKS.

SYSTEM MOVING FROM THE SRN PLAINS INTO THE EAST COAST MON INTO TUES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GFS/ECMWF/EC MEAN COMPROMISE
CONFIDENCE: AVERAGE

WHILE THE NAM IS IN SOMEWHAT BETTER AGREEMENT WITH THE 12Z EC WITH
REGARD TO TIMING OF S/WV LIFTING NEWD FROM THE SRN PLAINS/LOWER MS
VALLEY ON MON...ITS ASSOCD SFC LOW IS BY FAR THE WEAKEST OF THE
12Z AND 00Z GUIDANCE BY TUES MRNG AND TO THE EAST OF MUCH OF THE
GUIDANCE AS WELL.  BY CONTRAST...THE 12Z EC IS THE QUICKEST SOLN
AND DEEP BUT NOT AS DEEP AS THE UKMET WHICH HAS LOW RESPONDING TO
MUCH DEEPER AND FARTHER SOUTH UPSTREAM SYSTEM TRACKING INTO THE
MID MS VALLEY BY TUES MRNG.  CLEARLY THE INTERACTION OF THE LEAD
SRN STREAM S/WV WITH SYSTEM DROPPING IN BEHIND IT ACRS THE MID MS
VALLEY WILL IMPACT THE EVENTUAL TRACK AND INTENSITY OF THE LOW AS
IT LIFTS NEWD ALONG THE EAST COAST.  THE 00Z GFS TRENDED TOWARD
THE EC LIKELY A RESULT OF ITS DEEPER TREND TO UPSTREAM TROF.
SIMILAR TO THE SYSTEM ACRS THE MIDWEST/MID MS VALLEY...GIVEN THE
TREND OF THE GFS...A BLEND OF THE 00Z GFS WITH THE 12Z EC/EC MEAN
ARE PREFERRED


STG/MOIST FLOW INTO THE PAC NW
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-NAM COMPROMISE
CONFIDENCE: AVERAGE

A WEAK/WAVY BAROCLINIC BNDRY IS EXPECTED TO LIFT VERY SLOWLY NWD
ACRS THE PAC NW REGION STG UPR HIGH IS EXPECTED TO SLOWLY BUILD
EWD ACRS THE ERN PAC TOWARD CA. NORTH OF THE RIDGE...THE 00Z NAM
IS ON ITS OWN WITH A MUCH WEAKER AND FARTHER SOUTH SFC/UPR SYSTEM
WHICH RIDES OVER THE RIDGE TOWARD SW CANADA BY 12Z TUES.  OTHER
DETERMINISTIC GUIDANCE IS VERY TIGHTLY CLUSTERED FARTHER NORTH OF
THE 00Z NAM.  WHILE THERE ARE SOME QPF DIFFERENCES AS A RESULT OF
THESE DIFFERENCES...THE IMPACT DIFFERENCES ARE MORE SIGNIFICANT
HERE FOR MARINE INTERESTS WITH A NON-NAM SOLN GENLY PREFERRED.


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

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

SULLIVAN

$$





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