Skip Navigation Links weather.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
The Weather Prediction Center

 
 

 

Follow the Weather Prediction Center on Facebook Follow the Weather Prediction Center on Twitter
NCEP Quarterly Newsletter
WPC Home
Analyses and Forecasts
   National High & Low
   WPC Discussions
   Surface Analysis
   Days ½-2½ CONUS
   Days 3-7 CONUS
   Days 4-8 Alaska
   QPF
   PQPF
   Flood Outlook
   Winter Weather
   Storm Summaries
   Heat Index
   Tropical Products
   Daily Weather Map
   GIS Products
Current Watches/
Warnings

Satellite and Radar Imagery
   Satellite Images
   National Radar
Product Archive
WPC Verification
   QPF
   Medium Range
   Model Diagnostics
   Event Reviews
International Desks
Development and Training
   Development
WPC Overview
   About the WPC
   Staff
   WPC History
   Accomplishments
   Other Sites
   FAQs
Meteorological Calculators
Contact Us
   About Our Site
 
USA.gov is the U.S. Government's official web portal to all federal, state, and local government web resources and services.
 
Model Diagnostics Discussion
 
(Latest Discussion - Issued 0646Z Apr 27, 2015)
 
Version Selection
Versions back from latest:  0   1   2   3   4   5   6   7   8   9   10   
 
Abbreviations and acronyms used in this product
 
Geographic Boundaries -  Map 1: Color  Black/White       Map 2: Color  Black/White


MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
246 AM EDT MON APR 27 2015

VALID APR 27/0000 UTC THRU APR 30/1200 UTC

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

00Z MODEL EVALUATION
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


DEEP TROUGH/CLOSED LOW CURRENTLY OVER THE SOUTHWEST U.S.
LOW PRESSURE DEVELOPING OVER THE SOUTHERN PLAINS BY MON
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE THROUGH 12Z WED...GFS/ECMWF
COMPROMISE THEREAFTER
CONFIDENCE: AVERAGE

THROUGH EARLY WED...THE MODELS ARE SHOWING BETTER AGREEMENT WITH
THE 00Z NAM TRENDING TOWARD THE SLOWER CONSENSUS.  THE
NAM/GFS/ECMWF/UKMET ARE FAIRLY WELL CLUSTERED THROUGH 12Z WED. 
THEREAFTER...THE NAM REMAINS ON THE PROGRESSIVE SIDE OF THE
GUIDANCE WITH THE REMNANT SHORTWAVE MOVING ACROSS THE
SOUTHEAST/SOUTHERN MID-ATLANTIC AND THE SURFACE LOW TRACKING UP
THE SOUTHEAST COAST.


UPPER TROUGH DIGGING INTO THE GREAT LAKES LATE WED-THU
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 00Z GEFS MEAN/ECMWF
CONFIDENCE: AVERAGE TO BELOW AVERAGE

THERE IS LESS THAN AVERAGE CONFIDENCE ACROSS THE GREAT LAKES/OH
VALLEY LATE WED-THU AS A RESULT OF POOR RUN-TO-RUN CONTINUITY AND
ABOVE AVERAGE MODEL SPREAD WITH RESPECT TO THE EVOLUTION OF A
SHORTWAVE TROUGH FORECAST TO DIG INTO THE GREAT LAKES LATE
WED-THU.  BY LATE WED...THE NAM BEGAN TO TREND TOWARD A MORE
AMPLIFIED SOLUTION OVER THE GREAT LAKES...HOWEVER IT IS THE 00Z
GFS/UKMET THAT ARE SIGNIFICANT DEPARTURES FROM THEIR 12Z
RUNS...NOW SHOWING A DEEP LOW CLOSING OFF OVER THE GREAT LAKES
LATE WED...BEFORE SETTING INTO THE OH VALLEY BY EARLY WED.  AT THE
MOMENT THESE TWO MODELS ARE AT THE DEEP..SOUTHWEST SIDE OF THE
GUIDANCE...WHILE THE REMAINING MODELS ARE TO VARYING DEGREES MORE
SHEERED AND FURTHER TO THE NORTH.  THIS INCLUDES THE 00Z ECMWF
WHICH HAS TRENDED A LITTLE MORE AMPLIFIED...DIGGING THE TROUGH
FURTHER TO THE WEST ACROSS THE UPPER GREAT LAKES EARLY THU...BUT
NOT NEARLY TO THE DEGREE THAT THE GFS/UKMET ARE SHOWING.  WITH THE
00Z GEFS MEAN BETTER SUPPORTING THE 00Z ECMWF...WILL RECOMMEND
LEANING AWAY FROM THE GFS/UKMET.

UPPER TROUGHING OVER THE PACIFIC NORTHWEST TUE/WED
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GFS/NAM/UKMET
CONFIDENCE: AVERAGE

THE 00Z GFS IS MORE AMPLIFIED AND SLOWER WITH THE SHORTWAVE TROUGH
FORECAST TO MOVE ONSHORE LATE WED-THU...PUTTING IT INTO BETTER
AGREEMENT WITH THE NAM AND THE 00Z UKMET...WHICH HAS SLOWED AS
WELL.  THE 00Z ECMWF SHOWED A DISSIMILAR TREND AND IS FASTER AND
LESS AMPLIFIED THAN ITS 12Z RUN...WHICH SEEMS LESS LIKELY GIVEN
THE STRENGTH OF AN UPSTREAM RIDGE.


www.wpc.ncep.noaa.gov/html/model2.shtml...

www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml...

PEREIRA