ZCZC MIATCDAT3 ALL TTAA00 KNHC DDHHMM HURRICANE ISABEL DISCUSSION NUMBER 37 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 AM EDT MON SEP 15 2003 ISABEL IS SHOWING STRUCTURAL MIXED SIGNALS THIS EVENING. ON ONE SIDE...SATELLITE IMAGERY INDICATES THE EYE REMAINS WELL DEFINED AND THAT CLOUD TOPS NEAR THE EYE HAVE COOLED DURING THE PAST SEVERAL HOURS. ON THE OTHER...REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER INDICATE THE CENTRAL PRESSURE HAS RISEN TO 940 MB AND THAT THE MAXIMUM FLIGHT-LEVEL WINDS ARE 138 KT. THE AIRCRAFT HAS ALSO REPORTED WELL-DEFINED CONCENTRIC WIND MAXIMA. SUBJECTIVE SATELLITE INTENSITY ESTIMATES ARE 115 KT...AS ARE THE LATEST OBJECTIVE ESTIMATES. THE MAXIMUM WINDS ARE REDUCED TO 130 KT FOR THIS ADVISORY...AND THE STORM COULD BE A LITTLE WEAKER THAN THIS. WHILE THERE HAS BEEN A WOBBLE TO THE LEFT OVER THE PAST FEW HOURS... THE INITIAL MOTION IS 290/9...THE SAME DIRECTION AS EARLIER. WATER VAPOR IMAGERY SHOWS A LARGE ELONGATED RIDGE OF HIGH PRESSURE EXTENDING FROM SOUTHEASTERN CANADA SOUTHEASTWARD TO EAST OF ISABEL...AND WESTERLY FLOW WITH SEVERAL EMBEDDED SHORTWAVE TROUGHS OVER THE CENTRAL AND EASTERN UNITED STATES. ISABEL SHOULD BEGIN TO TURN NORTHWESTWARD AROUND THE WEST SIDE OF THE RIDGE DURING THE NEXT 12-24 HR...THEN GRADUALLY ACCELERATE NORTH-NORTHWESTWARD BETWEEN THE RIDGE AND THE BROAD TROUGHING TO THE WEST. ALL DYNAMICAL MODEL GUIDANCE AGREES WITH THIS SCENARIO...BRINGING ISABEL TO THE VICINITY OF THE MID-ATLANTIC COAST IN 72-96 HR. THE OFFICIAL FORECAST TRACK IS SIMILAR TO...BUT A LITTLE WEST OF THE PREVIOUS TRACK. SINCE THE TRACK IS FORECAST TO APPROACH THE COAST AT A SMALL ANGLE...A SMALL CHANGE IN DIRECTION COULD RESULT IN A LANDFALL WELL TO THE NORTH OF THE MID-ATLANTIC COAST. INTERESTS FROM THE CAROLINAS THROUGH THE NORTHEASTERN STATES SHOULD CLOSELY MONITOR THE PROGRESS OF ISABEL. ISABEL IS LIKELY TO CONTINUE IN A WARM-WATER LIGHT-SHEAR ENVIRONMENT FOR THE NEXT 36 HR...AND THUS FLUCTUATION IN INTENSITY FROM EYEWALL CONTRACTION CYCLES ARE LIKELY. BEYOND THAT TIME...THE HURRICANE WILL BE MOVING INTO THE UPPER-LEVEL SOUTHWESTERLY FLOW ASSOCIATED WITH THE TROUGH OVER THE UNITED STATES...AND THUS MAY EXPERIENCE SOME SHEAR. THE SHIPS MODEL SUGGESTS 30-40 KT OF SHEAR...AND IF THAT VERIFIES ISABEL COULD WEAKEN CONSIDERABLY. HOWEVER...THE LARGE-SCALE MODELS ARE NOT IN AGREEMENT ON THIS...SO THE INTENSITY FORECAST WILL CALL FOR ONLY A MODEST WEAKENING BEFORE LANDFALL. IT SHOULD BE NOTED THAT THE COASTAL SHELF WATER ALONG THE MID-ATLANTIC COAST IS RATHER COLD...AND ANY TRACK EAST OF CAPE HATTERAS THAT WOULD KEEP THE HURRICANE OVER THAT WATER WOULD LIKELY PRODUCE MORE WEAKENING THAN CURRENTLY FORECAST. FORECASTER BEVEN FORECAST POSITIONS AND MAX WINDS INITIAL 15/0900Z 24.8N 69.0W 130 KT 12HR VT 15/1800Z 25.5N 70.1W 130 KT 24HR VT 16/0600Z 26.5N 71.0W 130 KT 36HR VT 16/1800Z 27.9N 71.9W 125 KT 48HR VT 17/0600Z 29.2N 72.6W 120 KT 72HR VT 18/0600Z 33.5N 75.0W 115 KT 96HR VT 19/0600Z 40.0N 78.0W 60 KT...INLAND 120HR VT 20/0600Z 48.5N 80.0W 35 KT...INLAND EXTRATROPICAL NNNN
Alternate Formats
About Alternates -
E-Mail Advisories -
RSS Feeds
Cyclone Forecasts
Latest Advisory -
Past Advisories -
About Advisories
Marine Forecasts
Latest Products -
About Marine Products
Tools & Data
Satellite Imagery -
US Weather Radar -
Aircraft Recon -
Local Data Archive -
Forecast Verification -
Deadliest/Costliest/Most Intense
Learn About Hurricanes
Storm Names
Wind Scale -
Prepare -
Climatology -
NHC Glossary -
NHC Acronyms -
Frequently Asked Questions -
AOML Hurricane-Research Division
About Us
About NHC -
Mission/Vision -
Other NCEP Centers -
NHC Staff -
Visitor Information -
NHC Library
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
Privacy Policy
Credits
About Us
Glossary
Career Opportunities
Page last modified: Monday, 07-Feb-2005 16:49:58 UTC