Skip Navigation Links weather.gov   
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
National Hurricane Center
Local forecast by
"City, St" or "ZIP"

 
Alternate Formats
   Text     |   Mobile
   Email   |   RSS XML/RSS logo
   About Alternates
Cyclone Forecasts
   Latest Advisory
   Past Advisories
   Audio/Podcasts
   About Advisories
Marine Forecasts
   Atlantic & E Pacific
   Gridded Marine
   About Marine
Tools & Data
   Satellite | Radar
   Analysis Tools
   Aircraft Recon
   GIS Datasets
   Data Archive
Development
   Experimental
   Research
   Forecast Accuracy
Outreach & Education
   Prepare
   Storm Surge
   About Cyclones
   Cyclone Names
   Wind Scale
   Most Extreme
   Forecast Models
   Breakpoints
   Resources
   Glossary | Acronyms
   Frequent Questions
Our Organization
   About NHC
   Mission & Vision
   Staff | Q&A
   Visitors | Virtual Tour
   Library Branch
   NCEP | Newsletter
Contact Us
   Comments
Follow the National Hurricane Cent
er on Facebook Follow the National Hurricane Center on Twitter
FirstGov.gov is the U.S. Government's official Web portal to all Federal, state and local government Web resources and services.
 
 

Hurricane HELENE


ZCZC MIATCDAT3 ALL
TTAA00 KNHC DDHHMM
HURRICANE HELENE DISCUSSION NUMBER  39
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL082006
1100 PM EDT THU SEP 21 2006

THE SATELLITE REPRESENTATION OF HELENE HAS IMPROVED SLIGHTLY DURING
THE LAST COUPLE OF HOURS...AND COLD CLOUD TOPS HAVE EXPANDED AND
BECOME MORE CONCENTRIC AROUND THE CENTER.  DVORAK DATA-T NUMBERS
HAVE INCREASED TO 4.5 OR 77 KT FOR BOTH TAFB AND AFWA. 
ACCORDINGLY...THE INITIAL INTENSITY HAS BEEN BUMPED UP TO 75 KT.   

THE OFFICIAL INTENSITY FORECAST CLOSELY FOLLOWS THE SHIPS GUIDANCE. 
HELENE IS EXPECTED TO REMAIN OVER 26C TO 27C WATER FOR THE NEXT 24
HOURS OR SO WITH ONLY A MARGINAL INCREASE IN WEST-SOUTHWESTERLY
SHEAR.  THIS SHOULD KEEP HELENE IN A STEADY STATE FOR THE NEXT DAY. 
AFTER WHICH...VERY SLOW WEAKENING IS ANTICIPATED AS HELENE
TRANSITIONS INTO A POTENTIALLY STRONG EXTRATROPICAL CYCLONE IN
ABOUT 2 TO 3 DAYS...AS COLD AIR BECOMES ENTRAINED INTO THE WESTERN
SIDE OF THE CYCLONE.  

THE INITIAL MOTION IS NORTH-NORTHEASTWARD OR 015/12.  WATER VAPOR
IMAGERY INDICATES A BROAD DEEP-LAYER TROUGH RACING EASTWARD TOWARD
HELENE WITH A DRY PUNCH OUT AHEAD OF IT.  THIS TROUGH WILL HELP
ACCELERATE HELENE TO THE NORTH-NORTHEAST AND NORTHEAST FOR THE NEXT
48 TO 72 HOURS.  THE MODEL GUIDANCE IS CONSISTENT WITH THIS
SCENARIO...THEN THE MODELS DIVERGE A BIT AT DAYS 4 AND 5 AS HELENE
BECOMES EXTRATROPICAL.  THE UKMET IS THE GREATEST OUTLIER AND TAKES
HELENE TO THE EAST AND EVENTUALLY TO THE SOUTH...AND SHIFTS THE
CONSENSUS GUIDANCE TO THE SOUTH AS WELL.  THE GFS HAS A MORE
NORTHWARD TRACK WHILE THE GFDL...NOGAPS...AND FSU SUPERENSEMBLE
TAKE THE CYCLONE TO THE NORTHEAST.  THE OFFICIAL FORECAST IS
SLIGHTLY SOUTH OF THE PREVIOUS TRACK BUT REMAINS IN CLOSE AGREEMENT
WITH GFDL AND FSU SUPERENSEMBLE SOLUTIONS. 

THE WIND RADII HAVE BEEN ADJUSTED TO REFLECT DATA FROM A 2226 UTC
QUIKSCAT PASS. 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      22/0300Z 31.8N  56.3W    75 KT
 12HR VT     22/1200Z 33.6N  54.8W    75 KT
 24HR VT     23/0000Z 36.3N  51.2W    75 KT
 36HR VT     23/1200Z 38.9N  45.9W    70 KT
 48HR VT     24/0000Z 41.7N  40.0W    65 KT...BECOMING EXTRATROPICAL
 72HR VT     25/0000Z 47.0N  30.0W    60 KT...EXTRATROPICAL
 96HR VT     26/0000Z 51.5N  23.0W    60 KT...EXTRATROPICAL
120HR VT     27/0000Z 58.0N  17.0W    55 KT...EXTRATROPICAL
 
$$
FORECASTER MAINELLI/BEVEN
 
NNNN


Quick Navigation Links:
Tropical Cyclone Forecasts  -  Tropical Marine Forecasts  -  Data Archive
Outreach  -  Prepare  -  About Cyclones  -  About NHC  -  Contact Us

NOAA/ National Weather Service
National Centers for Environmental Prediction
National Hurricane Center
11691 SW 17th Street
Miami, Florida 33165-2149 USA
nhcwebmaster@noaa.gov
Disclaimer
Credits
Information Quality
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities
Page last modified: Friday, 22-Sep-2006 02:45:02 UTC