####018004476####
FXUS10 KWNH 310531
PMDHMD
 
MODEL DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1231 AM EST SAT JAN 31 2009
 
VALID JAN 31/0000 UTC THRU FEB 03/1200 UTC
 

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


00Z MODEL EVALUATION INCLUDING THE UKMET/CANADIAN GLBL


MODEL INITIALIZATION ERRORS DO NOT APPEAR TO HAVE A MEANINGFUL
IMPACT ON THE FORECAST.


...WAVY FRONT OVER THE NRN-CNTRL PLAINS BY MON-TUE...

BY MON NIGHT-EARLY TUE THE GFS DISPLAYS A FARTHER SWD PLAINS WAVE
THAN THE NAM... WHICH GOES ALONG WITH THE GFS BEING ABOUT 6 HRS
FASTER THAN THE NAM WITH SUPPORTING MID LVL ENERGY.  THE
UKMET/CANADIAN GLBL FAVOR SLOWER PROGRESSION OF SHRTWV ENERGY
CLOSER TO THE NAM IDEA... BUT OFFER VASTLY DIFFERENT SFC SOLNS. 
THE UKMET IS THE MOST AGGRESSIVE TO BUILD HIGH PRESSURE SWD OVER
THE CNTRL-ERN PLAINS WHILE BY F84 EARLY TUE THE CANADIAN GLBL
BRINGS LOW PRESSURE TO A NRN PLAINS POSN WHERE MODEL/ENSEMBLE
CONSENSUS SHOWS HIGH PRESSURE.  WILL RECOMMEND A COMPROMISE AMONG
THE NAM/21Z SREF MEAN/12Z ECMWF WHICH REPRESENTS CONSENSUS THAT IS
SLOWER THAN THE GFS ALOFT AND PROVIDES A GOOD INTERMEDIATE
POSITIONING OF THE SFC FRONT.

...WAVE REACHING THE UPR GRTLKS BY MON...

THE GFS/NAM SHOW SIMILAR TIMING WHICH IS AGREED UPON BY OTHER
MODEL/ENSEMBLE SOLNS.  THE GFS BECOMES SLIGHTLY STRONGER THAN THE
NAM WITH THE SFC REFLECTION BY F72 LATE MON.  THE 21Z SREF/12Z
ECMWF ENSEMBLE MEANS AND 12Z ECMWF GENERALLY SUPPORT THE DEEPER
GFS... THE UKMET A NAM/GFS COMPROMISE... AND THE CANADIAN GLBL
CLOSER TO THE NAM.  WEAKER TREND OF MID LVL ENERGY OVER THE PAST
DAY IN THE NAM AND TO A LESSER EXTENT THE GFS SEEMS TO FAVOR
LEANING AWAY FROM THE 12Z ECMWF THAT IS ELONGATED MORE NWWD THAN
EVEN THE GFS... SO WILL RECOMMEND A GFS/NAM COMPROMISE AT THIS
TIME.

...SYSTEM TRACKING JUST N OF THE GRTLKS BY SUN...

THE NAM/GFS SHOW ONLY MINOR DIFFS... WITH THE GFS TRACK JUST A TAD
S OF THE NAM AS THE SFC LOW TRACKS THRU ONTARIO.  THE 12Z ECMWF
OFFERS SUPPORT FOR THE FARTHER SWD GFS BUT LATEST SREF/GEFS/ECMWF
ENSEMBLES AND 00Z UKMET/CANADIAN GLBL OFFER ENOUGH SCATTERING TO
MAKE IT DIFFICULT TO FAVOR ONE SOLN OVER ANOTHER.  HOWEVER
VERIFICATION AND MODEST SWD TREND OVER THE PAST DAY MAY FAVOR
PUTTING SLIGHTLY MORE WEIGHT ON THE GFS/12Z ECMWF VERSUS THE NAM.

...TROF AMPLIFYING INTO THE EAST...
...ASSOC SFC EVOLUTION CNTRL CONUS TO WRN ATLC...

THE GFS IS FASTER/DEEPER THAN THE NAM WITH THE CORE OF THE MID LVL
TROF AMPLIFYING INTO THE EAST... EVENTUALLY SHOWING SOME NEUTRAL
TO NEGATIVE TILT.  THE GFS IS ALSO FASTER WITH ENERGY FLOWING
AROUND THE SWRN/SRN SIDE OF THE OVERALL TROF.  AS A RESULT THE GFS
BECOMES FASTER THAN THE NAM WITH THE WAVY FRONTAL BOUNDARY
REACHING SERN TX/LWR MS VALLEY SUN NIGHT... THEN DEEPER AND A
LITTLE EWD OF THE NAM OVER THE EAST COAST/WRN ATLC BY F84 EARLY
TUE.  THE 12Z ECMWF GENERALLY SUPPORTS THE GFS EVOLUTION WITH THE
CORE OF THE TROF BUT IN WEAKER FORM WHILE IT IS CLOSE TO THE
SLOWER NAM WITH ENERGY FLOWING AROUND THE SRN/SWRN SIDE OF THE
OVERALL TROF... YIELDING A SIMILAR BUT WEAKER WRN ATLC SFC LOW AT
THE END OF THE PERIOD.  THE CANADIAN GLBL ALSO FAVORS THE
GFS/ECMWF IDEA BUT MAY BE OVERDONE WITH ITS SFC LOW FROM THE NRN
GULF INTO THE WRN ATLC.  THE UKMET IS ALSO FASTER THAN THE NAM
WITH MOST OF THE ERN TROF AND ENDS UP WEAKER AND EWD/SEWD VERSUS
THE GFS WITH THE WRN ATLC SFC LOW BY F84.  THE 21Z SREF MEAN LEANS
MORE TOWARD THE GFS WITH BOTH ASPECTS OF THE TROF... BUT 18Z
GEFS/12Z ECMWF MEANS SEEM TO LEAN MORE TOWARD THE NAM.  WILL
RECOMMEND A GFS/12Z ECMWF BLEND AS THE MOST SIMPLE OPTION TO
ACCOUNT FOR CONSENSUS THAT IS FASTER THAN THE NAM WITH THE FRONT
OVER SERN TX/LWR MS VALLEY SUN NIGHT-MON... AND OPERATIONAL MODEL
TRENDS THAT HAVE ADJUSTED EWD OVER THE PAST DAY WITH THE CORE OF
THE MID LVL TROF AND ASSOC WRN ATLC SFC DEVELOPMENT.

...TROF DEPARTING FROM THE EAST...

WITH FLOW ACROSS NEW ENGLAND LATE SAT-SAT NIGHT THE 00 NAM IS MORE
AMPLIFIED THAN THE GFS AND OTHER OPERATIONAL MODELS AS WELL AS 21Z
SREF/18Z GEFS/12Z ECMWF ENSEMBLE MEANS.  PREFER THE GFS OR A BLEND
WITH OTHER NON-NAM SOLNS.

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

RAUSCH
$$