Prognostic Meteorological Discussion
Issued by NWS

000
FXUS10 KWNH 170446
PMDHMD

MODEL DIAGNOSTIC DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1245 AM EDT MON JUN 17 2013

VALID JUN 17/0000 UTC THRU JUN 20/1200 UTC

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

00Z INITIAL MODEL EVALUATION...INCLUDING THE NAM/GFS


...DEEP LAYER TROUGH MOVING ACROSS SOUTH-CENTRAL CANADA TO QUEBEC
AND THE NORTHEAST...

PREFERENCE: BLEND OF THE 00Z GFS/12Z ECMWF/21Z SREF MEAN
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

THE MODELS CONTINUE TO SHOW MID LEVEL SHORTWAVE ENERGY DROPPING
SEWD MON AND TUES ACROSS SRN QUEBEC AND ADVANCING ACROSS THE
NORTHEAST. ALL OF THE MODELS SHOW A CLOSED MID LVL LOW CENTER OVER
SRN QUEBEC BY MIDDAY TUES...WITH THE SYS THEN LIFTING OUT TO
NORTHEAST BY WED. THERE ARE SOME RELATIVELY MINOR DIFFS REGARDING
THE TIMING AND INTENSITY OF THE LOW.
THE 12Z UKMET IS ON THE FASTER SIDE OF THE MODEL SPECTRUM IN
TAKING THE ENERGY OUT TO THE NORTHEAST. THE 00Z GFS...00Z NAM AND
12Z ECMWF/21Z SREF MEAN/18Z GEFS MEAN CLUSTER WELL.


...MID LEVEL TROUGH MOVING EAST ACROSS THE LOWER MISSISSIPPI
VALLEY AND TN VALLEY THROUGH TUES...MID ATLANTIC TO CAROLINAS TUE
NIGHT-EARLY WED...

PREFERENCE: BLEND OF 00Z GFS/12Z ECMWF/18Z GEFS MEAN
CONFIDENCE: SLIGHTLY ABOVE AVERAGE

THE MODELS CONTINUE TO SHOW A MID LEVEL TROUGH EJECTING OUT OF THE
CNTRL PLAINS THROUGH THE LWR MS/TN VLYS MON AND MON NIGHT.  THE
12Z UKMET WAS A SLOW OUTLIER ON THE TIMING VS THE OTHER
MODELS/ENSEMBLE MEANS.  THE CANADIAN WAS A HIGH AMPLITUDE OUTLIER
AS WELL WITH ITS 700-500 MB WAVE.  THE 12Z ECMWF/12Z ECMWF
ENSEMBLE MEAN AND 00Z GFS DEVELOP A SFC WAVE WHICH CROSSES
EASTERN NC 00Z-12Z WED WHICH MOVES OFFSHORE AFTERWARD.  THE NAM
SHOWS A SIMILAR WAVE...AS DOES THE ECMWF ENSEMBLE MEAN..BUT JUST A
FEW MB WEAKER WITH THE SEA LEVEL PRESSURES.
THE GOOD AGREEMENT OF THE 00Z GFS/12Z ECMWF AND THEIR RESPECTIVE
ENSEMBLE MEANS SUGGESTS A BLEND OF THESE SOLUTIONS BE USED.

...DEEP CLOSED LOW MOVING ACROSS THE PACIFIC NORTHWEST AND
NORTHERN ROCKIES...

PREFERENCE: BLEND OF THE 00Z GFS/21Z SREF MEAN/12Z ECMWF ENSEMBLE
MEAN
CONFIDENCE: ABOVE AVERAGE

THE 00Z NAM/GFS CONTINUE TO CLUSTER WELL WITH THE 12Z ECMWF AND
12Z GEM GLOBAL...AS WELL AS THEIR RESPECTIVE ENSEMBLE MEANS WITH
THE LOCATION/TIMING/INTENSITY OF THE 500 MB LOW. THE 12Z UKMET
AGAIN APPEARS TO BE EJECTING ITS CLOSED LOW TOO QUICKLY INLAND
ACROSS THE PAC NORTHWEST TUES AND WED.  THE STRONGEST CLUSTERING
IS AMONG THE 00Z GFS/21Z SREF MEAN/12Z ECMWF ENSEMBLE MEAN...WHICH
ARE IN BETWEEN THE FASTER 00Z NAM/12Z UKMET AND SLOWER 12Z
CANADIAN GLOBAL/ECMWF.

...MODEL TREND GRAPHICS AT
WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML...
...500 MB FORECASTS AT
WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML...

PETERSEN

$$