794
FXUS10 KWNH 110640
PMDHMD
MODEL DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
139 AM EST WED NOV 11 2009
VALID NOV 11/0000 UTC THRU NOV 14/1200 UTC
...SEE NOUS42 KWNO ADMNFD FOR THE STATUS OF THE UPPER AIR
INGEST...
FINAL 00Z MODEL EVALUATION INCLUDING THE ECMWF
MODEL ANALYSIS ERRORS DO NOT APPEAR TO BE LARGE ENOUGH TO HAVE A
SIGNIFICANT IMPACT ON THE FORECAST.
..SHRTWV ENERGY ENTERING THE NORTHWEST ON FRI
PREFERENCE: GFS/ECMWF BLEND
THRU F60 EARLY FRI THE GFS IS SLIGHTLY FLATTER/FASTER THAN THE NAM
ALOFT BUT DIFFS AT THE SFC ARE MINIMAL. AS THE ERN PAC ENERGY
FLOWS INLAND DURING FRI-FRI NIGHT THE GFS CONTINUES TO BE WEAKER
AND A TAD FASTER THAN THE NAM OVER THE NRN HALF/TWO THIRDS OF THE
WEST... BUT THE GFS IS STRONGER THAN THE NAM WITH SRN ENERGY
REACHING THE SWRN CONUS/NRN BAJA CALIF AND VICINITY BY F84 EARLY
SAT. SUPPORT FROM OTHER GUIDANCE FOR THE NAM AMPLITUDE WITH THE
NRN STREAM ENERGY IS MODEST SO FAR BUT ECMWF RUNS ARE NOT TOO FAR
FROM THE NAM AMPLITUDE. THE 00Z GEFS MEAN IS SLIGHTLY
WEAKER/BROADER THAN THE GFS. OTHER SOLNS INCLUDING THE 21Z SREF
MEAN/12Z ECMWF ENSEMBLE MEAN AND 12Z-00Z UKMET/CMC ARE FLATTER AND
MORE PROGRESSIVE TO VARYING DEGREES. THE 00Z NAM REPRESENTS A
MORE AMPLIFIED ADJUSTMENT FROM PAST RUNS... WHILE GFS RUNS HAVE
BEEN INCONSISTENT. THE 00Z GFS LIES BETWEEN THE FLATTER/FASTER
12Z RUN AND SLOWER/MORE AMPLIFIED 00Z/11 RUN. THE VIGOROUS SYSTEM
THAT SOME GUIDANCE SHOWS TRACKING ALONG THE NRN PAC/ALEUTIANS INTO
THE NERN PAC APPEARS TO OFFER SOME SUPPORT FOR DOWNSTREAM
AMPLIFICATION... SO A SOLN IN THE SLOWER HALF OF THE SPREAD SEEMS
REASONABLE. ADJUSTMENT OF THE ECMWF FROM A NAM/GFS COMPROMISE TO
BEING NEAR THE SLOW EDGE OF GUIDANCE REINFORCES THIS IDEA. WILL
RECOMMEND A GFS/ECMWF BLEND THAT IS A LITTLE WEAKER WITH THE CORE
OF THE SHRTWV THAN THE NAM AND IS NEAR THE MIDDLE OF THE SPREAD OF
GFS RUNS FROM THE PAST DAY. FARTHER SWD... THIS BLEND TONES DOWN
THE STRENGTH OF GFS ENERGY REACHING THE SWRN CONUS/NRN BAJA CALIF
BY THE END OF THE PERIOD.
..TROF PROGRESSING THRU THE WEST WED ONWARD
PREFERENCE: ECMWF
THE NAM IS DEEPER THAN THE GFS AND MOST OTHER GUIDANCE WITH BOTH
THE NRN AND SRN PORTIONS OF THE OVERALL TROF PROGRESSING FROM THE
WEST INTO THE PLAINS. AT SOME FCST HRS THE NAM IS ALSO NEAR THE
SLOW EDGE OF THE GUIDANCE ENVELOPE WITH PORTIONS OF THE SFC
REFLECTION OVER THE PLAINS. THE UKMET CONVERGES TO THE NAM SOLN
WITH THE SFC WAVE REACHING THE UPR MS VALLEY BY FRI NIGHT THOUGH.
MEANWHILE BY EARLY SAT THE GFS IS ONE OF THE WEAKEST SOLNS AT THE
SFC OVER THE UPR MS VALLEY/GRTLKS... AND IS EVEN WEAKER THAN THE
18Z-00Z GEFS MEANS. 18Z/12Z GFS RUNS WERE SOMEWHAT STRONGER AND
CLOSER TO THE AVERAGE OF CURRENT GUIDANCE. THE CANADIAN GLBL IS
AN EXTREME PROGRESSIVE SOLN AND IS DISCOUNTED. THE 00Z ECMWF HAS
TRENDED A LITTLE WEAKER TO A COMPROMISE SOLN NEAR THE 00Z GEFS
MEAN BY THE END OF THE FCST... WHICH LEAVES THE ECMWF AS THE BEST
INTERMEDIATE SOLN THRU THE FCST PERIOD.
..REMNANTS OF IDA
..SYSTEM EVOLVING NEAR THE EAST COAST
PREFERENCE: GFS/UKMET/ECMWF COMPROMISE
GIVEN FAIRLY MODEST SCATTER A COMPROMISE AMONG LATEST GUIDANCE
SHOULD PROVIDE A REASONABLE FCST FOR THE REMNANTS OF IDA EARLY IN
THE PERIOD. WITH THE SYSTEM EVOLVING NEAR THE EAST COAST... THE
NAM BECOMES DEEPER THAN THE GFS AND MOST OTHER GUIDANCE WITH THE
MID LVL LOW BY F48 LATE THU AND THIS DIFFERENCE PERSISTS FOR THE
REST OF THE PERIOD. ALSO THE NAM BECOMES SLOWER WITH THE SYSTEM
VERSUS THE GFS BY FRI-FRI NIGHT. DIFFS ALOFT RESULT IN A NAM SFC
LOW THAT EXTENDS SOMEWHAT FARTHER NWD THAN MOST OTHER SOLNS
ESPECIALLY AROUND F60 EARLY FRI. ON THE OTHER HAND REMAINING
SOLNS GENERALLY KEEP THE MID LVL SYSTEM A LITTLE SWD OF THE GFS BY
F84 EARLY SAT. PREFER A GFS/UKMET/ECMWF COMPROMISE TO INCORPORATE
THE CONSENSUS NON-NAM ASPECTS OF LATEST GUIDANCE AND ACCOUNT FOR
REMAINING DETAIL DIFFS THAT ARE TYPICALLY DIFFICULT TO RESOLVE 2-3
DAYS OUT IN TIME.
...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
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