Prognostic Meteorological Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4
000
FXUS10 KWNH 241849
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
245 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 MODEL EVALUATION INCLUDING FINAL PREFERENCES AND FORECAST
CONFIDENCE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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...12Z ECMWF BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

THE 12Z UKMET/CMC REMAIN 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 / 12Z 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 12Z CMC ALSO ENDS UP ON THE
DEEPER SIDE OF THE GUIDANCE. THE REMAINING 12Z GFS...12Z
ECMWF...12Z UKMET GUIDANCE IS IN GOOD AGREEMENT UNTIL SAT WHEN THE
GFS LEANS TOWARD THE QUICKER SIDE OF THE ENSEMBLE/DETERMINISTIC
SPREAD. THE 12Z 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 12Z ECMWF. IT SHOULD BE NOTED THAT THE
12Z GEFS MEAN WAS CLOSER TO THE 12Z ECMWF/00Z ECMWF ENSEMBLE MEAN
POSITION...WHICH EXAGGERATED THE SPEED OF THE FASTER 12Z GFS
SOLUTION.


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

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

$$





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