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 ISAAC


ZCZC MIATCDAT4 ALL
TTAA00 KNHC DDHHMM
 
TROPICAL STORM ISAAC DISCUSSION NUMBER   8
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092012
1100 PM AST WED AUG 22 2012
 
AN AIR FORCE HURRICANE HUNTER AIRCRAFT INVESTIGATED ISAAC SEVERAL
HOURS AGO AND FOUND THAT THE CENTER WAS STILL NOT WELL-DEFINED AND
THE INTENSITY ESTIMATE OF 40 KT WAS PROBABLY A LITTLE ON THE HIGH
SIDE.  HOWEVER...DROPSONDE DATA FROM A NOAA AIRCRAFT CURRENTLY
INVESTIGATING THE STORM SUGGEST THAT THE CENTER HAS PROBABLY BECOME
A LITTLE BETTER DEFINED AND THAT THE MINIMUM PRESSURE HAS DROPPED A
BIT.  THERE HAS ALSO BEEN AN INCREASE IN COLD-TOPPED CONVECTION
NEAR AND OVER THE ESTIMATED CENTER SO THE CURRENT INTENSITY IS HELD
AT 40 KT.  ISAAC HAS DEVELOPED AN IMPRESSIVE UPPER-LEVEL OUTFLOW
PATTERN AND DYNAMICAL GUIDANCE SHOWS THAT THE VERTICAL SHEAR SHOULD
REMAIN WEAK DURING THE NEXT SEVERAL DAYS.  THEREFORE THE PRIMARY
IMPEDIMENT TO STRENGTHENING SHOULD BE THE INTERACTION WITH THE
MOUNTAINOUS TERRAIN OF HISPANIOLA AND EASTERN CUBA.  THE MOST
RECENT RUNS OF THE HWRF AND GFDL SHOW SIMILAR AMOUNTS OF LAND
INTERACTION BUT ARE NOT IN GOOD AGREEMENT ON THE INTENSITY FORECAST
AS THE FORMER MODEL SHOWS MUCH LESS STRENGTHENING THAN THE LATTER.
THE OFFICIAL WIND SPEED FORECAST IS IN REASONABLE AGREEMENT WITH
THE LATEST STATISTICAL-DYNAMICAL GUIDANCE.

AFTER A SLIGHT SOUTHWARD RELOCATION OF THE CENTER...THE INITIAL
MOTION CONTINUES BASICALLY WESTWARD OR 270/17.  ISAAC SHOULD
CONTINUE TO MOVE WESTWARD TO WEST-NORTHWESTWARD FOR THE NEXT COUPLE
OF DAYS ALONG THE SOUTHERN PERIPHERY OF THE SUBTROPICAL RIDGE.  THE
GLOBAL MODELS CONTINUE TO DEPICT A BREAK IN THE RIDGE IN THE
VICINITY OF FLORIDA IN SEVERAL DAYS...WHICH SHOULD INDUCE A MORE
NORTHWARD COMPONENT OF MOTION.  THE ECMWF MODEL SHOWS LESS OF A
BREAK IN THE RIDGE THAN THE GFS SOLUTION.  CONSEQUENTLY...THE ECMWF
TRACK IS SOMEWHAT TO THE SOUTHWEST OF MOST OF THE OTHER TRACK
MODELS WHICH WOULD LESSEN THE THREAT TO FLORIDA.  THE OFFICIAL
TRACK FORECAST FOR THIS ADVISORY IS QUITE CLOSE TO THE PREVIOUS ONE
AND ALSO VERY CLOSE TO THE DYNAMICAL MODEL CONSENSUS.

FORECAST POSITIONS AND MAX WINDS
 
INIT  23/0300Z 15.8N  63.0W   40 KT  45 MPH
 12H  23/1200Z 16.2N  65.4W   45 KT  50 MPH
 24H  24/0000Z 16.9N  68.1W   55 KT  65 MPH
 36H  24/1200Z 17.5N  70.5W   65 KT  75 MPH
 48H  25/0000Z 18.6N  72.7W   55 KT  65 MPH
 72H  26/0000Z 21.5N  77.0W   60 KT  70 MPH...ON NORTH COAST OF CUBA
 96H  27/0000Z 24.0N  80.5W   65 KT  75 MPH
120H  28/0000Z 27.0N  83.5W   70 KT  80 MPH
 
$$
FORECASTER PASCH
 
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: Monday, 31-Dec-2012 12:09:26 UTC