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 9 10
000
FXUS10 KWNH 041646
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1245 PM EDT MON MAY 04 2015

VALID MAY 04/1200 UTC THRU MAY 08/0000 UTC

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

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

UPPER TROUGH OVER CENTRAL CANADA AND ASSOCIATED COLD FRONT MOVING
  THROUGH NEW ENGLAND TONIGHT
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE:  GENERAL MODEL COMPROMISE
CONFIDENCE:  ABOVE AVERAGE

MODEL MASS FIELDS ARE IN GOOD AGREEMENT THROUGH THE SHORT RANGE
WITH ONLY MINOR AMPLITUDE DIFFERENCES REGARDING THE UPPER TROUGH
INTO WEDNESDAY...BUT BY THAT POINT...THE UPPER TROUGH IS OFFSHORE.


SHORTWAVE TROUGH OVER THE PACIFIC NORTHWEST DROPPING INTO THE
  SOUTHWEST U.S. WED
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z GFS/00Z ECMWF
CONFIDENCE: AVERAGE

THE GFS/ECMWF SHOW THE BEST AGREEMENT TO THE LATEST ENSEMBLE MEANS
AND SPAGHETTI HEIGHT CLUSTERING ACROSS THE WEST BY THU
MORNING...WITH NO SIGNIFICANT TRENDS NOTED IN THE ENSEMBLES.
THEREFORE...STAYING TOWARD THE MEANS APPEARS MOST REASONABLE AT
THIS TIME.


SHORTWAVE TROUGH MOVING FROM THE SOUTHWEST TODAY/TUE...TO THE CNTRL
  PLAINS FOR WED/THU
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z GFS/00Z ECMWF
CONFIDENCE: SLIGHTLY BELOW AVERAGE

THERE ARE SOME NOTABLE MID-LEVEL DIFFERENCES BETWEEN THE GFS AND
ECMWF...WITH THE EVOLUTION OF VORTICITY MAXIMA REACHING THE CNTRL
PLAINS ON WED. THE 00Z ECMWF PUTS MORE EMPHASIS ON THE NRN PORTION
OF THE TROUGH BY THU WHEREAS THE 12Z GFS AND REMAINING GUIDANCE IS
SIMILAR WITH WEIGHT TOWARD THE SRN END...WITH MANY MODELS TRENDING
TOWARD THE GFS MID-LEVEL EVOLUTION. HOWEVER...REGARDING THE
SFC-850 MB REFLECTION...THE ENSEMBLES SUPPORT SOMEWHERE BETWEEN
THE GFS/ECMWF ALTHOUGH SPREAD WITH THE DETAILS REMAINS LARGE.


LOW PRESSURE LIKELY NEARING THE SOUTHEAST COAST BY THE MIDDLE/END
OF
  THE WEEK
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z GFS
CONFIDENCE: AVERAGE

ECMWF/GEFS/CMC ENSEMBLE SCATTER LOW PLOTS HAVE SHOWN RELATIVELY
GOOD CLUSTERING WITH POSITION OVER THEIR PAST FEW 00/12Z
CYCLES...BUT THE 00Z/04 CYCLE HAS SHIFTED CLOSER TO THE COAST BY
WED EVENING...WITH A CENTROID NEAR 29N 78W. THIS POSITION IS BEST
MATCHED BY THE 12Z GFS WITH THE ECWMF SHOWING TRENDS IN THE
DIRECTION OF THE GFS OVER ITS PAST FEW CYCLES.



...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

$$





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