THE WEATHER PREDICTION CENTER

COLLEGE PARK, MD


MODEL DIAGNOSTIC DISCUSSION


[Abbreviations and acronyms used in this product]
Geographic boundaries:    Map 1- [Color] [B/W Print Version]      Map 2 - [Color] [B/W Print Version]



MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
108 PM EDT SAT AUG 27 2016

VALID AUG 27/1200 UTC THRU AUG 31/0000 UTC

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

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


UPPER TROUGH CROSSING NORTHERN PLAINS/UPPER MIDWEST TODAY
ENERGY CROSSING OVER TO NEW ENGLAND ON MON
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: ABOVE AVERAGE

THE GUIDANCE SHOWS GOOD AGREEMENT WITH THIS SYSTEM.


UPPER TROUGH DROPPING SOUTH THROUGH BRITISH COLUMBIA ON SAT
ENERGY CROSSING SOUTHERN CANADA SUN/MON
COLD FRONT MOVING THROUGH THE NORTHERN PLAINS/UPPER MIDWEST SUN/MON
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 12Z NAM...12Z GFS...00Z ECMWF
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

THE 00Z CMC/UKMET REMAIN JUST SLIGHTLY DEEPER/FASTER WITH THE
UPPER TROUGH COMPARED TO THE REMAINING GUIDANCE. WHILE MINOR
TIMING DIFFERENCES EXIST WITH THE RELATED COLD FRONT...DECENT
AGREEMENT EXISTS BETWEEN THE 12Z NAM/GFS AND 00Z ECMWF.


UPPER TROUGH DIGGING SOUTH OFFSHORE BRITISH COLUMBIA BY MON
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: AVERAGE

THE MODELS SHOW REASONABLE AGREEMENT WITH THIS SYSTEM.


COMPACT MID-LEVEL SHORTWAVE APPROACHING NRN CA TUE MORNING
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON 00Z UKMET BLEND
CONFIDENCE: ABOVE AVERAGE

WITH THE EXCEPTION OF THE GFS...TRENDS HAVE BEEN TO BE MUCH
QUICKER WITH THIS FEATURE COMPARED TO YESTERDAY...AND
CURRENTLY...THE DETERMINISTIC GUIDANCE FORMS A GOOD CONSENSUS WITH
THE TIMING OF THE WAVE TUE MORNING. THE EXCEPTION IS THE FASTER
00Z UKMET WHICH IS NOT PREFERRED.


MID LEVEL TROUGH OVER THE SOUTHWEST THIS WEEKEND
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 12Z GFS AND 00Z ECMWF
CONFIDENCE: AVERAGE

WHILE THERE IS BROAD AGREEMENT WITH THE EVOLUTION OF THIS
FEATURE...THE 12Z NAM ENDS UP ON THE STRONGER SIDE OF THE LATEST
GUIDANCE. THE 00Z UKMET/CMC HANG BACK MORE ENERGY OVER THE
SOUTHWEST...WHICH IS POSSIBLE BUT THE LATEST ENSEMBLE MEANS
SUPPORT A GFS/ECMWF BLEND THROUGH TUE.


LOW PRESSURE APPROACHING SOUTH OF FL AND INTO THE GULF OF MEXICO
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: BLEND OF THE 12Z GFS AND 00Z ECMWF
CONFIDENCE: BELOW AVERAGE

THE DETERMINISTIC GUIDANCE CONTINUES TO STRUGGLE WITH THE HANDLING
OF THIS SYSTEM. THE 00Z UKMET/CMC REMAIN STRONG AND THE 12Z NAM
CONTINUES TO STRENGTHEN MULTIPLE VORTICITY MAXIMA NEAR AND EAST OF
THE FL PENINSULA. THE LOW LEVEL REFLECTION IN THE NAM IS EAST OF
THE DETERMINISTIC CONSENSUS AND ON THE EASTERN END OF THE LATEST
ENSEMBLE CLUSTERING. MEANWHILE...THE ECMWF HAS STAYED TOWARD ITS
TREND IN STRENGTH TOWARD THE GFS WHICH REMAINS RATHER WEAK AND
DISORGANIZED. GIVEN A BETTER LACK OF SUPPORT FOR THE STRONGER
UKMET/CMC SOLUTIONS...AND VERIFICATION OF A WEAKER SYSTEM TO
DATE...WILL CONTINUE TO PREFER THE WEAKER AND OFTEN BETTER
PERFORMING...GFS/ECMWF CLUSTER.


WEAK MID LEVEL LOW CENTER NEAR THE WESTERN GULF COAST TODAY/SUN
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: GENERAL MODEL COMPROMISE
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

DESPITE SOME MINOR SYNOPTIC DIFFERENCES...THE MODELS SHOW DECENT
AGREEMENT WITH THE TRACK AND INTENSITY OF THIS SYSTEM.


MID-UPPER LEVEL TROUGH APPROACHING THE SOUTHEAST COAST FROM THE
  ATLANTIC SUN/MON
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: 12Z GFS...00Z ECMWF...00Z UKMET BLEND
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

THE 00Z CMC IS AN EASTERN OUTLIER WITH THIS SYSTEM AND THE 12Z NAM
DOES NOT MATCH THE POSITION OF THE AGREEABLE GFS/ECMWF/UKMET.

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...





Last Updated: 108 PM EDT SAT AUG 27 2016