Prognostic Meteorological Discussion
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FXUS10 KWNH 241636
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1235 PM EDT WED AUG 24 2016

VALID AUG 24/1200 UTC THRU AUG 28/0000 UTC

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

12Z NAM/GFS EVALUATION INCLUDING PRELIMINARY PREFERENCES
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

700-500 MB TROUGH OVER LOWER MICHIGAN THIS AFTERNOON...REACHING NRN
  NEW ENGLAND THU
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: AVERAGE

THE MODELS SHOW SIMILARLY WITH THIS FEATURE.


MID-LEVEL TROUGH OVER S-CNTRL CANADA...MOVING EAST INTO ONTARIO THU
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z NAM...12Z GFS...00Z ECMWF BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

THE 00Z UKMET/CMC ARE FLATTER AND FASTER WITH THE LOW-MID LEVEL
WAVE COMPARED TO THE REMAINING DETERMINISTIC/ENSEMBLE GUIDANCE BY
12Z/FRI WITH THESE DIFFERENCES CONTINUING INTO THE WEEKEND. WHILE
MINOR DIFFERENCES EXIST WITH THE NAM/GFS/ECMWF...A BLEND IS
PREFERRED TO IRON OUT DETAIL DIFFERENCES.


MID-LEVEL TROUGH OVER THE SRN ROCKIES TODAY...WEAKENING INTO THE
  CNTRL PLAINS THROUGH THU
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: AVERAGE

THE MODELS SHOW SIMILARLY WITH THIS FEATURE.


MID-UPPER TROUGH OVER THE NWRN U.S. EVENTUALLY REACHING
  THE NRN PLAINS SAT
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z GFS / 00Z ECMWF BLEND
CONFIDENCE: SLIGHTLY BELOW AVERAGE

THE 12Z NAM IS DEEPER ON THE LEADING EDGE OF THE TROUGH ENTERING
THE PLAINS FRI EVENING...AND THE 00Z CMC ALSO ENDS UP ON THE
DEEPER SIDE OF THE GUIDANCE. THE REMAINING 12Z GFS...00Z
ECMWF...00Z UKMET GUIDANCE IS IN GOOD AGREEMENT UNTIL SAT WHEN THE
GFS LEANS TOWARD THE QUICKER SIDE OF THE ENSEMBLE/DETERMINISTIC
SPREAD. THE 00Z ECMWF ENDS UP TOWARD THE DEEPER SIDE OF THE SPREAD
WITH THE UKMET FLATTER.

BY 00Z/28...GIVEN THE RANGE OF SOLUTIONS SEEN IN THE LATEST
ENSEMBLE SPAGHETTI PLOTS...GOING TOWARD THE ENSEMBLE MEANS APPEARS
TO BE THE BEST APPROACH. THIS POSITION IS BETWEEN THE FASTER 12Z
GFS AND THE SLOWER/DEEPER 00Z ECMWF.


UPPER TROUGH DROPPING SOUTH THROUGH SWRN BRITISH COLUMBIA SAT
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z GFS...00Z ECMWF...00Z UKMET BLEND
CONFIDENCE: AVERAGE

THE 12Z GFS...00Z ECMWF...00Z UKMET SHOW REASONABLE AGREEMENT WITH
EACH OTHER AND THE LATEST ENSEMBLE GUIDANCE. THE 12Z NAM IS
QUICKER WITH THE UPPER TROUGH WHILE THE 00Z CMC IS BROADER.


OTTO

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

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

$$





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