Prognostic Meteorological Discussion
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000
FXUS10 KWNH 121615
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1215 PM EDT SAT JUL 12 2014

VALID JUL 12/1200 UTC THRU JUL 16/0000 UTC

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

==================================================
12Z NAM/GFS EVALUATION AND PRELIMINARY PREFERENCES
==================================================
NAM/GFS INITIALIZATION ERRORS DO NOT APPEAR TO
SIGNIFICANTLY AFFECT THEIR LARGE SCALE OUTPUT.
==================================================

...DEEP CYCLONE DROPPING INTO MICHIGAN MONDAY/TUESDAY...

PREFERENCE: BLEND OF 00Z UKMET/CANADIAN...SUPPORTED BY 00Z ECMWF
ENSEMBLE MEAN

RECENT RUNS OF THE NAM AND GFS JUMP AHEAD OF THE OTHER MODELS
GOING INTO DAY 2 AND 3 AS A SHORTWAVE WHIPS AROUND THE BASE OF THE
UPPER TROUGH DIGGING INTO THE GREAT LAKES. IT APPEARS THESE
QUICKER SOLUTIONS ARE DEPENDENT UPON A LESSER DEFINED WESTWARD
EXTENSION OF THE SHORTWAVE AND SOME PHASING WITH A LEAD WAVE THAT
MATURES OVER EASTERN ONTARIO SUNDAY NIGHT. GIVEN THAT THIS PLAYS
INTO THE NAM/GFS BIASES...WE STILL PREFER THE SLOWER MODEL
CONSENSUS. THE OPERATIONAL ECMWF...HOWEVER...CONTINUES TO DEFINE
THE OUTER EDGE OF THE ENVELOPE ON THE DEEP/SLOW SIDE...SO OUR
PREFERENCE IS TOWARD THE ECMWF ENSEMBLE MEAN...ALSO REPRESENTED BY
THE 00Z UKMET/CANADIAN.


...SHORTWAVE TROUGH AFFECTING THE NORTHWEST AND NORTHERN ROCKIES...

PREFERENCE: BLEND OF THE OPERATIONAL MODELS

THE MODELS ARE REASONABLY SIMILAR IN THEIR PREDICTIONS OF THE
TIMING AND DEPTH OF THIS FEATURE AT 700-500 MB...AND IN THEIR
PRECIPITATION OUTPUT.


...INVERTED UPPER TROUGH SKIRTING THE SOUTHWEST U.S...

PREFERENCE: BLEND OF THE OPERATIONAL MODELS

THE SAME AS WAS WRITTEN IN THE SECTION ABOVE COULD BE STATED
REGARDING THIS SYSTEM. MODELS ARE SIMILAR. THE ECMWF HAS BEEN MORE
AGGRESSIVE IN CARRYING AN ANOMALOUS MOIST PLUME WEST THROUGH
SOUTHERN CALIFORNIA. EVEN THE MORE CONSERVATIVE GFS PRODUCES A
PLUME OF 2 TO 3 STANDARD DEVIATIONS ABOVE CLIMATOLOGY...OPENING
THE POSSIBILITY OF SOME DIURNAL THUNDERSTORM ACTIVITY TOWARD LOS
ANGELES AND EVEN WESTWARD...AS WELL AS AN EXPANSION OF ACTIVITY
NORTHWARD INTO THE SIERRAS.

...MODEL TREND GRAPHICS AT
www.wpc.ncep.noaa.gov/html/model2.shtml...
...500 MB FORECASTS AT
www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml...

BURKE
$$





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