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 Center on Facebook Follow the National Hurricane Center on Twitter
Subscribe the National Hurricane Center on YouTube Read the National Hurricane Center Inside the Eye blog on WordPress
FirstGov.gov is the U.S. Government's official Web portal to all Federal, state and local government Web resources and services.
 
 

Tropical Storm OPHELIA


ZCZC MIATCDAT1 ALL
TTAA00 KNHC DDHHMM
 
TROPICAL STORM OPHELIA DISCUSSION NUMBER  12
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL162011
500 PM AST FRI SEP 23 2011
 
DEEP CONVECTION HAS REDEVELOPED NEAR AND OVER THE LOW-LEVEL CENTER
DURING THE PAST 6 HOURS...AND REPORTS FROM AN AIR FORCE RESERVE
RECONNAISSANCE AIRCRAFT INDICATE THE INTENSITY HAS INCREASED TO 50
KT BASED ON FLIGHT-LEVEL WINDS OF 60 KT AND BELIEVABLE SFMR SURFACE
WINDS OF 50-51 KT.
 
THE INITIAL MOTION IS 285/13...AFTER ONCE AGAIN HAVING TO SMOOTH
THROUGH ALL OF THE WIGGLES AND WOBBLES IN THE TRACK. THE
DEVELOPMENT OF THE DEEP CONVECTION NEAR THE CENTER LIKELY PULLED
THE BARELY-CLOSED LOW-LEVEL CIRCULATION CENTER NORTHWESTWARD...
WHICH IS BELIEVED TO BE A TEMPORARY MOTION.  OTHERWISE...THERE HAS
BEEN NO SIGNIFICANT CHANGE TO THE PREVIOUS FORECAST TRACK. MOST OF
THE MODEL GUIDANCE SHIFTED TO THE RIGHT DUE TO THE MORE NORTHWARD
INITIAL POSITION...BUT THE SUBTROPICAL RIDGE TO THE NORTH OF
OPHELIA IS FORECAST BY ALL OF THE GLOBAL MODELS TO REMAIN QUITE
STRONG...WHICH SHOULD KEEP THE CYCLONE MOVING IN A GENERAL
WEST-NORTHWESTWARD MOTION FOR THE NEXT 48 HOURS OR SO. BY 72 HOURS
AND BEYOND...THE WESTERN PORTION OF THE RIDGE IS FORECAST TO ERODE
AS A MID-/UPPER-LEVEL TROUGH MOVES EASTWARD ACROSS FLORIDA AND THE
BAHAMAS. THIS SHOULD CAUSE OPHELIA TO SLOW DOWN AND TURN
NORTHWESTWARD BY DAYS 3-4...AND THEN ALLOW FOR A GRADUAL NORTHWARD
TURN BY DAY 5. THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE
PREVIOUS ADVISORY TRACK...AND LIES NEAR THE SOUTHERN OR LEFT SIDE
OF THE NHC GUIDANCE ENVELOPE.

ALTHOUGH THE GFS-BASED SHIPS MODEL IS ASSESSING NEAR 20 KT OF
SOUTHWESTERLY SHEAR ACROSS THE CYCLONE...THE UW-CIMSS MID-LEVEL
SHEAR ANALYSES INDICATE THE SHEAR IS 15 KT OR LESS. THIS HAS LIKELY
ALLOWED THE RECENT RESURGENCE IN INNER CORE CONVECTION. HOWEVER...
THIS BRIEF RESPITE IS EXPECTED TO BE SHORT-LIVED AS ALL OF THE
GLOBAL MODELS ARE FORECASTING THE VERTICAL SHEAR TO INCREASE TO
MORE THAN 25 KT IN 12-18 HOURS. THERE WILL CONTINUE TO BE
FLUCTUATIONS IN THE MAGNITUDE OF THE VERTICAL SHEAR FOR THE NEXT 96
HOURS...WHICH WILL RESULT IN THE WAXING AND WANING OF THE CENTRAL
DEEP CONVECTION...BUT THE GENERAL TREND SHOULD BE FOR GRADUAL
WEAKENING TO OCCUR. HOWEVER...BY DAY 5...SOME SLIGHT STRENGTHENING
IS POSSIBLE AS THE SHEAR DECREASES AND OPHELIA MOVES UNDERNEATH OR
NEAR A SMALL UPPER-LEVEL ANTICYCLONE.

FORECAST POSITIONS AND MAX WINDS
 
INIT  23/2100Z 15.5N  53.8W   50 KT  60 MPH
 12H  24/0600Z 16.3N  55.7W   50 KT  60 MPH
 24H  24/1800Z 17.5N  58.0W   45 KT  50 MPH
 36H  25/0600Z 18.6N  60.0W   45 KT  50 MPH
 48H  25/1800Z 19.7N  61.8W   40 KT  45 MPH
 72H  26/1800Z 21.8N  64.9W   40 KT  45 MPH
 96H  27/1800Z 24.0N  66.6W   40 KT  45 MPH
120H  28/1800Z 26.5N  67.5W   45 KT  50 MPH
 
$$
FORECASTER STEWART
 
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 USA
nhcwebmaster@noaa.gov
Disclaimer
Credits
Information Quality
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities
Page last modified: Tuesday, 17-Jul-2012 13:44:06 UTC