berrywr
(Weather Analyst)
Mon Nov 09 2009 06:25 PM
Re: Ida Again Tropical Storm Moving Toward Gulf

This is the Model Diagnostic Discussion courtesy of HPC pertaining to Ida and future evolution of its remains::

MODEL DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
147 PM EST MON NOV 09 2009

VALID NOV 09/1200 UTC THRU NOV 13/0000 UTC


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

12Z MODEL EVALUATION INCLUDING THE NEW ECMWF AND FINAL PREFERENCES

INITIALIZATION ERRORS WITH THE NAM/GFS DO NOT APPEAR TO
SIGNIFICANTLY IMPACTS THEIR FORECASTS.

Excerpt follows:

PREFERENCE: 1/2 EACH GFS/ECMWF

...HURRICANE IDA...
...INTERACTION OF IDA WITH SHORTWAVE TROUGH OVER TEXAS...

THE MAJORITY OF MODELS...INCLUDING THE NAM...ALLOW THE APPROACHING
SHORTWAVE TROUGH TO PULL IDA IN A NORTHWESTERLY DIRECTION UNTIL
THEY CONSOLIDATE NEAR THE GULF COAST BY 12Z TUE. HOWEVER...
THE NAM LIES NEAR THE SOUTHWEST OR SLOW EDGE OF THE GUIDANCE
DURING THIS PROCESS AND IS CONSIDERED LEAST RELIABLE...WHILE ALL
OTHER GUIDANCE...INCLUDING THE GFS/ECMWF ALLOW THE CONSOLIDATED
LOW TO DRIFT EASTWARD INTO THE FLORIDA PANHANDLE BY TUE...WHICH IS
IN GOOD AGREEMENT WITH HURRICANE MODEL GUIDANCE. REFER TO THE TPC
FOR THE OFFICIAL FORECAST.

...SHORTWAVE TROUGH AMPLIFYING OVER THE EAST TUE/WED...

PREFERENCE: 1/2 GEFS MEAN TO 1/4 EACH GFS/CANADIAN

THERE HAS BEEN A NOTABLE TREND IN THE MAJORITY OF GUIDANCE THE
LAST TWO DAYS TO DELAY A COMPLICATED PHASING PROCESS OF THIS
TROUGH WITH A SEPARATE SHORTWAVE TROUGH MOVING INTO THE SOUTHEAST
UNTIL BOTH TROUGHS REACH THE EAST COAST. THE NAM AND MULTI-MODEL
ENSEMBLE MEANS WERE FIRST TO DISPLAY A LESS-PHASED OR UNPHASED
SOLUTION 1-2 DAYS AGO...WITH THE DETERMINISTIC GUIDANCE SLOWLY
COMING INTO AGREEMENT. THE NEW NAM CONTINUES TO SHOW NO
PHASING...BUT IS MOSTLY DUE TO ITS SLOW OUTLIER SOLUTION IN THE
GULF...SO THE NAM CAN NOT PHASE. MEANWHILE THE NEW GFS HAS TRENDED
TOWARD SLOWER AND WEAKER PHASING...RESULTING IN A LESS PRONOUNCED
SURFACE LOW OFF THE GA/SC COAST...WITH REASONABLY GOOD SUPPORT
PROVIDED FROM THE CANADIAN AND GEFS MEAN...
ALBEIT WEAKER AND MORE SUPPRESSED THAN THE GFS. THE ECMWF/UKMET
NOW REMAIN THE ONLY DETERMINISTIC SOLUTIONS SUPPORTING
CONSIDERABLE SURFACE LOW DEVELOPMENT OFF THE SC COAST BY THU.
THUS...WILL MAINTAIN CONTINUITY WITH PRIOR REASONING THAT THE
POSITIVELY-TILTED LONGWAVE PATTERN AND ITS SUBSEQUENT SHORTWAVE
PATTERN SUPPORT A SUPPRESSED AND PROGRESSIVE SURFACE LOW
EVOLUTION...WHICH IS CLOSEST TO THE GEFS MEAN.

...MODEL TREND GRAPHICS AT
www.HPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML...

...500 MB FORECASTS AT
www.HPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML...



Note: This is NOT an official page. It is run by weather hobbyists and should not be used as a replacement for official sources. 
CFHC's main servers are currently located at Hostdime.com in Orlando, FL.
Image Server Network thanks to Mike Potts and Amazon Web Services. If you have static file hosting space that allows dns aliasing contact us to help out! Some Maps Provided by:
Great thanks to all who donated and everyone who uses the site as well. Site designed for 800x600+ resolution
When in doubt, take the word of the National Hurricane Center