Prognostic Meteorological Discussion
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9

000
FXUS10 KWNH 280634
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
133 AM EST FRI NOV 28 2014

VALID NOV 28/0000 UTC THRU DEC 01/1200 UTC

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


00Z MODEL EVALUATION WITH PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NAM/GFS INITIALIZATION ISSUES DO NOT SEEM TO DEGRADE THEIR SHORT
RANGE FORECASTS.


SHORTWAVE MOVING TOWARDS THE PACIFIC NW SUN/MON
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE GUIDANCE IS IN GOOD AGREEMENT WITH THIS SYSTEM.


SHORTWAVE APPROACHING CALIFORNIA SAT NIGHT
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GFS/ECMWF/UKMET COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE 00Z NAM BECOMES TOO STRONG WITH THIS SYSTEM -- ITS USUAL BIAS.
 THE 12Z CANADIAN IS THE WEAKEST, WEAKER THAN BOTH THE 12Z
ECMWF/18Z GEFS ENSEMBLE MEANS.  A COMPROMISE OF THE 00Z GFS/12Z
UKMET/12Z ECMWF IS PREFERRED WITH THIS SYSTEM WITH ABOVE AVERAGE
CONFIDENCE.


SHORTWAVE MOVING THROUGH THE NORTHWEST/NRN PLAINS
FRONT MOVING THROUGH NEW ENGLAND LATE SUN/EARLY MON
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: ECMWF/GFS/UKMET COMPROMISE
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

WITH THE MAIN TROUGH AXIS, THE 00Z CANADIAN LAGS BEHIND THE OTHER
GUIDANCE FROM LATE SATURDAY INTO SUNDAY (ITS USUAL BIAS) BEFORE
CATCHING UP TO THE CONSENSUS.  A SHORTWAVE MOVING AROUND ITS
EASTERN SIDE LEADS TO TIMING ISSUES WITH A COLD FRONT MOVING INTO
THE NORTHEAST, WITH THE 00Z GFS/18Z GEFS MEAN THE QUICKEST (THEIR
USUAL BIAS) AND THE 00Z CANADIAN/12Z ECMWF ENSEMBLE MEANS THE
SLOWEST (A BIAS SEEN IN THE CANADIAN AND OCCASIONALLY IN THE
ECMWF).  IN GENERAL, A COMPROMISE BETWEEN THE 00Z ECMWF/00Z GFS
APPEARS BEST, WHICH IN NEW ENGLAND, IS CLOSEST TO THE 00Z UKMET IN
REGARDS TO FRONTAL TIMING.  CONFIDENCE IS SLIGHTLY ABOVE AVERAGE
IN THIS PREFERENCE.


UPPER TROUGH MOVING THROUGH NORTHERN MEXICO/TX
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE GUIDANCE IS IN VERY GOOD AGREEMENT WITH THE SHORTWAVE MOVING
THROUGH NORTHERN MEXICO INTO TEXAS.


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

ROTH
$$





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