Prognostic Meteorological Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12
000
FXUS10 KWNH 011611
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1210 PM EDT WED APR 01 2015

VALID APR 01/1200 UTC THRU APR 05/0000 UTC

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

12Z NAM/GFS EVALUATION WITH PRELIMINARY MODEL PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
INITIALIZATION ERRORS WITH THE NAM/GFS DO NOT SEEM TO DEGRADE
THEIR SHORT RANGE FORECASTS.


DEEP CYCLONE OFFSHORE THE NORTHWEST FRIDAY/SATURDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-UKMET COMPROMISE
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

THE 00Z UKMET IS A SOUTHERLY/MORE AMPLIFIED OUTLIER WITH THIS
SYSTEM.  WHILE THIS SOLUTION IS POSSIBLE CONSIDERING THE BUILDING
RIDGE UPSTREAM IN THE PACIFIC, THE 00Z ECMWF/06Z GEFS MEAN
SOLUTIONS FAVOR A NON-UKMET COMPROMISE.  CONFIDENCE IN THIS
SOLUTION IS SLIGHTLY ABOVE AVERAGE.


CYCLONE MOVING FROM THE SOUTHERN PLAINS THROUGH THE EAST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GFS/UKMET COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THERE ARE SOME SPEED/TRACK ISSUES WITH THIS SYSTEM, WITH THE 12Z
NAM SHOWING A MORE DEPRESSED TRACK, AND THE 00Z CANADIAN/TO SOME
DEGREE THE 00Z ECMWF ON THE SLOW SIDE OF THE GUIDANCE -- A TYPICAL
BIAS FOR THE CANADIAN.  THE 00Z ECMWF/06Z GEFS ENSEMBLE MEAN
SOLUTIONS BEST SUPPORT A COMPROMISE OF THE 12Z GFS/00Z UKMET,
WHICH IS PREFERRED WITH ABOVE AVERAGE CONFIDENCE.


SYSTEM MOVING BY THE GREAT LAKES/NORTHEAST THU/FRI
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE GUIDANCE SHOWS GOOD AGREEMENT WITH THIS SYSTEM.


SYSTEM STREAKING THROUGH THE SOUTHEAST WED/THU
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GFS/ECMWF COMPROMISE
CONFIDENCE: AVERAGE

THERE IS MORE THAN THE USUAL SPREAD WITH THIS SYSTEM`S STRENGTH,
AS THE 00Z UKMET IS THE WEAKEST (ITS USUAL BIAS WITH WEAK SYSTEMS)
WHILE THE 00Z ECMWF IS THE STRONGEST.  NORMALLY, GOING WITH A
SOLUTION NEAR OR SLIGHTLY STRONGER THAN THE ENSEMBLE MEAN
SOLUTIONS WORKS OUT, WHICH LEADS TO A COMPROMISE OF THE 12Z
GFS/00Z ECMWF SOLUTIONS WITH AVERAGE CONFIDENCE.


...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.