MODEL DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
144 AM EST SUN NOV 08 2009
 
VALID NOV 08/0000 UTC THRU NOV 11/1200 UTC
 

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


FINAL 00Z MODEL EVALUATION INCLUDING THE ECMWF


MODEL INITIALIZATION ERRORS ARE INDICATED UNDER THE RELEVANT
SYSTEM HEADING.


...NERN PAC ENERGY NEARING THE PAC NW TUE NIGHT...

PREFERENCE:  GFS/ECMWF/CANADIAN GLBL BLEND

BY F84 EARLY WED THE NAM IS SOMEWHAT SLOWER THAN THE GFS WITH THE
PORTION OF THE OVERALL MID LVL TROF AND LEADING SFC REFLECTION
NEARING THE PAC NW COAST.  CONFIDENCE IN A SPECIFIC MODEL IS BELOW
AVERAGE DUE TO VARIED SHRTWV DETAILS... AND SUFFICIENTLY DIVERSE
ENSEMBLE GUIDANCE WHOSE MEANS SMOOTH OUT INDIVIDUAL SHRTWVS WITHIN
THE OVERALL MEAN TROF.  THE AVERAGE OF MODEL/ENSEMBLE SOLNS LEANS
SLIGHTLY FASTER THAN THE NAM ALOFT... SO WILL RECOMMEND A
GFS/ECMWF/CANADIAN GLBL COMPROMISE AS THE BEST OPTION AT THIS
TIME.


...FRONT REACHING THE PAC NW ON MON...

PREFERENCE:  GFS/ECMWF/CANADIAN GLBL COMPROMISE

BY TUE-TUE NIGHT THE NAM BECOMES SLOWER THAN THE GFS AND THE
MAJORITY OF OPERATIONAL MODELS AND ENSEMBLE MEANS WITH THE SFC
FRONT AND SUPPORTING MID LVL SHRTWV.  PROGRESSIVE NATURE OF THE
FLOW CARRYING THE SHRTWV WOULD FAVOR LEANING TOWARD THE FASTER
GFS... THOUGH SLOWER GFS/FASTER NAM TRENDS OVER THE PAST DAY
INDICATE POTENTIAL FOR AN INTERMEDIATE SOLN TO PREVAIL.  SLIGHTLY
SLOWER ADJUSTMENT OF THE 00Z ECMWF FROM ITS 12Z RUN CONTINUES THE
THEME OF MIXED TRENDS.  AS THE UKMET/CMC OFFER SUPPORT FOR A SOLN
FASTER THANT HE NAM... WILL RECOMMEND A GFS/ECMWF/CMC COMPROMISE
WITH THE UKMET POSSIBLY A LITTLE TOO FAST AS PER ITS TYPICAL BIAS
WITH NRN STREAM FLOW.


...TROF REACHING THE EAST BY TUE NIGHT...

PREFERENCE:  BLEND AMONG 12Z ECMWF AND UKMET/00Z GEFS MEAN

THE NAM IS SOMEWHAT STRONGER THAN THE GFS WITH LEADING SHRTWV
ENERGY WHICH IS FCST TO TRACK TO THE N OF MAINE ON TUE... CAUSING
THE NAM TO BE DEEPER AND SLIGHTLY WWD OF THE GFS WITH THE SFC WAVE
THAT TRACKS OVER SERN CANADA MON-MON NIGHT.  MEANWHILE THE GFS
BECOMES INCREASINGLY SHARPER AND MORE AMPLIFIED THAN THE NAM WITH
TRAILING ENERGY THAT REACHES THE ERN STATES BY TUE NIGHT...
ALLOWING THE GFS TO PULL A SFC WAVE UP TO NEAR THE NC COAST BY
EARLY WED IN CONTRAST TO THE HIGHER PRESSURES WHICH THE NAM BUILDS
INTO THE MID ATLC AND VICINITY.  

WITH LEADING TROF ENERGY... REMAINING MODELS ARE NOT AS STRONG AS
THE NAM AND EVEN HINT AT SLOWER TIMING THAN EITHER THE GFS OR
NAM... WHICH HAVE ADJUSTED FASTER OVER THE PAST 12-24 HRS.  AS A
RESULT CONSENSUS IS WEAKER THAN THE NAM WITH THE WAVE THAT TRACKS
ACROSS SERN CANADA MON-MON NIGHT.  

BY F84 EARLY WED THE FULL ARRAY OF GUIDANCE CONTINUES TO SHOW
CONSIDERABLE SPREAD WITH THE TROF ALOFT AS HAS BEEN THE CASE IN
RECENT DAYS.  THE MOST STABLE ASPECT OF GUIDANCE THUS FAR HAS BEEN
FOR ENSEMBLE MEANS TO BE FAIRLY PROGRESSIVE WITH LITTLE HINT OF
FLOW SEPARATION WITHIN THE TROF BY EARLY WED.  THE 00Z GEFS MEAN
MAINTAINS THIS THEME.  THE 00Z ECMWF HAS ADJUSTED SLOWER TO LEAN
ON THE WRN SIDE OF THE SOLN SPREAD BY EARLY WED... AND IN LIGHT OF
RECENT SOLN SPREAD/RUN TO RUN VARIABILITY PREFER NOT TO
INCORPORATE THE 00Z ECMWF INTO THE FCST AT THIS TIME.  THE 12Z
ECMWF TIMING COMPARES BETTER TO ENSEMBLE MEAN CONSENSUS BUT
APPEARS TO BECOME TOO DEEP WITH THE MID LVL TROF/ASSOC SFC LOW
LATE IN THE FCST.  THE UKMET IS A MORE MODERATE SOLN FAIRLY CLOSE
TO THE ENSEMBLE MEAN IDEA.  UNTIL A BETTER OPERATIONAL CLUSTER
EMERGES... PREFER A BLEND OF THE 12Z ECMWF AND UKMET/00Z GEFS MEAN
AS THE BEST INTERMEDIATE SOLN THRU THE FCST PERIOD.


...UPPER LOW INITIALLY OVER NRN MEXICO...
...GULF OF MEXICO ENERGY REACHING THE LOWER MS VALLEY...
...HURRICANE IDA...

CONSULT THE LATEST TPC DISCUSSION/ADVISORY FOR FURTHER INFO
REGARDING HURCN IDA.  CONFIDENCE IN ANY MODEL SOLN IS MINIMAL AS
00Z MODEL ANALYSES ARE ABOUT 15 MB TOO WEAK WITH THE CNTRL
PRESSURE.  ALSO THE NAM POSN IS ABOUT 25 NM FARTHER SWWD THAN THE
00Z TPC POSN.  PERHAPS DUE TO THE WEAK INITIALIZATIONS... THE
GFS/NAM AND UKMET/CMC/ECMWF TRACK IDA WWD OF THE 03Z TPC ADVISORY
TRACK INTO EARLY TUE BEFORE SOME SOLNS COMPARE BETTER FOR A SHORT
TIME LATER IN THE FCST.  THE 00Z ECMWF BECOMES THE FASTEST SOLN BY
F36 EARLY MON.  ADDING TO THE UNCERTAINTY IS THE POTENTIAL
INTERACTION OF MULTIPLE FEATURES INCLUDING THE UPPER LOW INITIALLY
CROSSING NRN MEXICO AND ONE OR MORE PIECES OF SHRTWV ENERGY
STREAMING NWD OVER THE GULF OF MEXICO INTO THE SRN CONUS... AS
WELL AS POSSIBLE LATE PERIOD INFLUENCE FROM THE NRN STREAM ENERGY
REACHING THE ERN CONUS.  BASED ON A 12Z ECMWF/UKMET/00Z GEFS MEAN
BLEND WITH THIS LATTER TROF... IT SHOULD HAVE LESS OF AN IMPACT
THAN INDICATED BY THE GFS.


...FRONT REACHING NEW ENGLAND ON SUN...

THE NAM/GFS ALONG WITH OTHER RECENT GUIDANCE DISPLAY GOOD
AGREEMENT WITH THIS FEATURE.


...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