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 030417
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1216 AM EDT THU SEP 03 2015

VALID SEP 03/0000 UTC THRU SEP 06/1200 UTC

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

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


NEGATIVELY-TILTED SYSTEM MOVING ACROSS THE NORTHWEST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: CLOSEST TO THE 12Z ECMWF
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

THE 12Z CANADIAN IS THE SLOWEST WITH THIS SYSTEM`S PROGRESSION
(ITS USUAL BIAS) WHILE THE 12Z ECMWF/12Z UKMET APPEAR TO BE THE
QUICKEST (AGAINST USUAL ECMWF TRENDS IN THE 3-4 DAY TIME RANGE
THOUGH ALONG THE LINES OF KNOWN UKMET BIASES).  THE STRENGTH ALOFT
OF THE 00Z NAM CAUSES ITS SURFACE LOW SOLUTION IN MONTANA TO
BECOME THE MOST WESTERLY SATURDAY NIGHT -- ITS USUAL BIAS.  THE
12Z ECMWF/18Z GEFS MEANS LIE IN BETWEEN THE EXTREMES AND ARE
SIMILAR TO THE 12Z ECMWF.  THE 12Z ECMWF APPEARS BEST HERE WITH
SLIGHTLY ABOVE AVERAGE CONFIDENCE.


RETROGRADING UPPER LOW MOVING INTO THE SOUTHEAST SAT/SUN
700 HPA LOW LOOPING ACROSS MI THURSDAY & FRIDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE GUIDANCE IS IN GOOD AGREEMENT WITH THESE SYSTEMS.


...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.