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
000
FXUS10 KWNH 011650
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1149 AM EST SUN MAR 01 2015

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

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

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


INITIAL UPPER LOW/TROUGH DRIFTING THROUGH CA/NV THRU MON
ASSOCIATED SFC LOW / COLD FRONT MOVING OUT OVR THE CNTRL PLAINS
TUE TO GRT LAKES WED
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 01/00Z ECMWF AND 01/12Z GFS
CONFIDENCE: AVERAGE

THE MODELS STILL SHOW MORE SEPARATION BETWEEN THE INITIAL
SHORTWAVE OVER SOUTHERN CA TODAY AND TONIGHT WITH A SECOND
SHORTWAVE TROF DROPPING SOUTH ALONG THE WEST COAST OF NORTH
AMERICA. THE NAM HAS BEEN STRUGGLING WITH THE INTENSITY AND
PLACEMENT OF THE SHORTWAVES.  IT HAS FAIRLY DECENT AGREEMENT WITH
OTHER MODELS INTO LATE MONDAY NIGHT/EARLY TUESDAY NIGHT BEFORE IT
AMPLIFIES A TROF DROPPING SOUTH FROM CANADA WHERE THE EC/GFS DO
NOT.  GIVEN THAT THE 01/12Z GFS HAD BETTER RUN TO RUN
AGREEMENT...AND THE FACT THAT THE GFS AND ECMWF TOOK THE
DEVELOPING SFC LOW OVER THE PLAINS ON PRETTY MUCH THE SAME TRACK
WHILE THE NAM WAS TAKING A TRACK WEST OF THE GFS/ECMWF...WILL
THINK GFS/ECMWF SOLNS ARE BETTER OPTIONS AT THIS POINT.  THOSE
SOLNS HAVE THE SUPPORT OF THEIR RESPECTIVE ENSEMBLES.


SECONDARY SHORTWAVE ENERGY DIVING SOUTHWARD ALONG THE WA/OR COAST
EARLY MONDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON 00Z UKMET/NAM BLEND
CONFIDENCE: AVERAGE

THERE IS STRONG SUPPORT FOR THIS SHORTWAVE TO BE FARTHER OFFSHORE
THAN WHAT IS SHOWN BY THE UKMET AND NAM THROUGH MON...WITH THE
REMAINING MODEL CONSENSUS IN REASONABLE AGREEMENT.


NRN STREAM SHORTWAVE TRACKING FROM THE N-CNTRL U.S. TO NEW ENGLAND
ASSOCIATED COLD FRONT PUSHING THROUGH THE NRN HIGH PLAINS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 01/12Z GFS...01/00Z ECMWF BLEND
CONFIDENCE: AVERAGE

AGREE WITH PREVIOUS FORECASTER THAT WHILE THE GFS MAY RETREAT COLD
AIR TOO QUICKLY ACROSS THE SOUTHERN PLAINS...IT IS PRETTY MUCH A
NON FACTOR DURING LATER PERIODS OF THE SHORT RANGE.  WE DO NOTE
THAT THE TWO CAMPS OF MODELS SOLN...ONE THAT IS FARTHER WEST WITH
A COASTAL FRONT ALONG THE EAST COAST AND SUBSEQUENT SURFACE LOW
DEVELOPMENT...AND ANOTHER CAMP FARTHER EAST. CURRENTLY...THE
SREF/GEFS/EC ENSEMBLES SUPPORT A NAM/GFS/ECWMF BLEND OF
MODELS...TOWARD THE MIDDLE OF THE SPREAD.   THE BETTER CLUSTERING
OF THE GFS/ECMWF ARE PREFERRED AT THIS TIME.  GIVEN THE RUN TO RUN
STRUGGLES BY THE NAM UPSTREAM...AM RELUCTANT TO INCLUDE IT IN THE
PREFERENCES AT THIS TIME.

...MODEL TREND GRAPHICS AT
www.wpc.ncep.noaa.gov/html/model2.shtml...

...500 MB FORECASTS AT
www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml...

BANN

$$





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