Prognostic Meteorological Discussion
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8
000
FXUS10 KWNH 130439
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1238 AM EDT SUN JUL 13 2014

VALID JUL 13/0000 UTC THRU JUL 16/1200 UTC

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

==============================================
00Z NAM/GFS EVALUATION AND PRELIMINARY PREFERENCES
==============================================
NAM/GFS INITIALIZATION ERRORS DO NOT APPEAR TO
SIGNIFICANTLY AFFECT THEIR LARGE SCALE OUTPUT.
==============================================

...DEEP CYCLONE DROPPING INTO MI MON/TUE...

PREFERENCE: BLEND OF 00Z GFS/12Z UKMET
CONFIDENCE: AVERAGE

THE 00Z NAM IS ON THE FASTER EDGE OF THE MODEL SOLUTION ENVELOPE
WITH ITS DEPICTION OF THE CLOSED MID LEVEL LOW AND ITS LONG WAVE
TROUGH POSITION. THE 00Z GFS HAS CONTINUED TO SLOW ITS PROGRESSION
WITH RESPECT TO THE DEEP MID LEVEL CYCLONE...AND NOW MORE CLOSELY
RESEMBLES THE 12Z UKMET POSITION. THE 12Z ECMWF IS STILL ON THE
SOUTHWEST SIDE OF THE GUIDANCE THROUGH DAY 2. AFTER THAT...THE
CLOSED LOW SLOWS DOWN...AND THE ECMWF LONG WAVE TROUGH POSITION
GETS CLOSER TO THE CONSENSUS POSITION. DESPITE THE DIFFERENCES IN
THE TIMING OF THE EXIT OF THE CLOSED MID LEVEL SYSTEM AND
EVOLUTION OF THE LONG WAVE TROUGH...THERE WAS GENERALLY GOOD MODEL
AGREEMENT CONCERNING THE TIMING OF THE FRONT ON THE EAST COAST.


...SHORTWAVES AFFECTING THE NORTHWEST AND NORTHERN ROCKIES ON
MON/TUE...

PREFERENCE: 00Z GFS/12Z UKMET/12Z CMC
CONFIDENCE: ABOVE AVERAGE

THE FIRST SHORT WAVE ORIGINATING ALONG THE WEST COAST CROSSES THE
PACIFIC NORTHWEST AND NORTHERN ROCKIES DURING DAY 2...AND THERE
WAS GOOD MODEL AGREEMENT WITH THE TRACK AND TIMING OF THIS SHORT
WAVE. A SECOND SHORT WAVE DROPPING OUT OF WEST CENTRAL CANADA
CROSSES THE NORTHERN ROCKIES ON DAY 3. THE 00Z NAM AND 12Z UKMET
ARE FASTER WITH THE TIMING OF THIS SHORT WAVE...WHILE THERE IS
BETTER CLUSTERING OVER MT/WY WITH THE 00Z GFS/12Z ECMWF/12Z CMC.


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

PREFERENCE: GENERAL MODEL BLEND
CONFIDENCE: ABOVE AVERAGE

BOTH THE 00Z NAM AND 00Z GFS CLUSTERED WELL WITH RESPECT TO THE
INVERTED UPPER TROUGH CROSSING THE SOUTHWEST STATES INTO
CA...INCLUDING THEIR DEPICTION OF THE MOISTURE PLUME ASSOCIATED
WITH IT.


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

HAYES

$$





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.