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 IVAN


ZCZC MIATCDAT4 ALL
TTAA00 KNHC DDHHMM
HURRICANE IVAN DISCUSSION NUMBER  35
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT FRI SEP 10 2004
 
DURING THE AFTERNOON...THE AIR FORCE RESERVE HURRICANE HUNTER
AIRCRAFT MONITORING IVAN REPORTED A PRESSURE FALL FROM 940 MB TO
926 MB IN ABOUT 5 HOURS.  SINCE THEN...THE HURRICANE HAS CONTINUED
TO BECOME BETTER ORGANIZED...WITH SATELLITE INTENSITY ESTIMATES IN
THE 127-140 KT RANGE.  ONE CONUNDRUM IS THAT THE AIRCRAFT COULD NOT
FIND A FLIGHT-LEVEL WIND OF HIGHER THAN 123 KT...WHICH WOULD NOT
SUPPORT CATEGORY 4 INTENSITY.  THE INITIAL INTENSITY IS INCREASED
TO 135 KT BASED ON THE SATELLITE SIGNATURE...THE ESTIMATED
PRESSURE...AND THE PREMISE THAT THE WINDS ARE CATCHING UP WITH THE
PRESSURE.

THE INITIAL MOTION HAS BEEN WOBBLING AROUND 300/9.  THERE IS NO
CHANGE IN THE TRACK FORECAST PHILOSOPHY.  IVAN SHOULD MOVING
WEST-NORTHWESTWARD AROUND A WEAKENING SUBTROPICAL RIDGE...THEN
GRADUALLY TURN TOWARD THE NORTHWEST OR NORTH AFTER 48 HR AS THE
RIDGE STRENGTHENS IN THE ATLANTIC AND A TROUGH DROPS SOUTHWARD OVER
THE NORTHERN GULF COAST.  ALL GUIDANCE AGREES WITH THE BASIC
SCNEARIO...WITH THE GFS CALLING FOR AN EARLIER TURN AND LANDFALL ON
THE SOUTHWEST FLORIDA PENINSULA AND THE NOGAPS CALLING FOR A MORE
NORWARD MOTION TO THE CENTRAL FLORIDA PANHANDLE.  THE OTHER DYNAMIC
MODELS ARE IN BETWEEN...AS IS THE FORECAST TRACK...WHICH IS
BASICALLY AN UPDATE OF THE PREVIOUS TRACK AND TAKE IVAN TO THE
FLORIDA BIG BEND REGION IN 96 HR.  A SLIGHT CHANGE TO THE RIGHT OF
THE TRACK COULD BRING IVAN INLAND ANYWHERE ALONG THE WEST COAST OF
FLORIDA.

IVAN HAS WELL-DEFINED CONCENTRIC EYEWALLS SEEN IN AIRCRAFT...
MICROWAVE SATELLITE...AND EARLIER JAMAICAN RADAR DATA.  THIS
SUGGESTS THAT THE CURRENT INTENSIFICATION HAS MAYBE 6-12 HR TO
RUN...AND THAT IS NOT ALLOWING FOR ANY LAND EFFECTS AS THE SYSTEM
CROSSES JAMAICA SHORTLY.  AS THE SYSTEM CROSSES THE NORTHWESTERN
CARIBBEAN DURING THE NEXT 24-36 HR...THE UPPER-LEVEL WINDS SHOULD
REMAIN FAVORABLE ENOUGH TO ALLOW IVAN TO REGAIN CATEGORY 5 STATUS
AT SOME POINT DURING ITS FLUCTUATIONS DURING THE EYEWALL CYCLES. 
AFTER 48 HR...A GRADUAL INCREASE IN SHEAR AND INTERACTION WITH LAND
SHOULD CAUSE A GRADUAL WEAKENING.  HOWEVER...IVAN SHOULD REMAIN A
MAJOR HURRICANE UNTIL LANDFALL IN FLORIDA.
 
FORECASTER BEVEN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      11/0300Z 17.5N  76.9W   135 KT
 12HR VT     11/1200Z 18.3N  77.9W   135 KT
 24HR VT     12/0000Z 19.3N  79.1W   140 KT
 36HR VT     12/1200Z 20.4N  80.4W   140 KT
 48HR VT     13/0000Z 21.8N  81.5W   140 KT
 72HR VT     14/0000Z 25.0N  83.0W   115 KT
 96HR VT     15/0000Z 30.0N  83.5W   100 KT...INLAND
120HR VT     16/0000Z 35.5N  83.0W    30 KT...INLAND
 
 
$$
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: Saturday, 11-Sep-2004 02:42:59 UTC