Skip Navigation Links
NOAA NOAA United States Department of Commerce

Hurricane OPHELIA


ZCZC MIATCDAT1 ALL
TTAA00 KNHC DDHHMM
HURRICANE OPHELIA DISCUSSION NUMBER  15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT FRI SEP 09 2005
 
THE SATELLITE SIGNATURE OF OPHELIA HAS BECOME LESS IMPRESSIVE DURING
THE EVENING...WITH A SIGNIFICANT DECREASE IN BOTH THE COVERAGE AND
INTENSITY OF THE CONVECTION.  AN AIR FORCE RESERVE HURRICANE HUNTER
AIRCRAFT REPORTS THAT THE CENTRAL PRESSURE HAS RISEN TO 985 MB...
AND THE THAT MAXIMUM 850 MB FLIGHT-LEVEL WINDS SO FAR HAVE BEEN 65
KT 25-30 N MI SOUTHEAST OF THE CENTER.  IT APPEARS THAT A
COMBINATION OF 20 KT SOUTHWESTERLY SHEAR AND DRY AIR INTRUSION HAS
AT LEAST TEMPORARILY DISRUPTED THE CONVECTIVE STRUCTURE.  THE
INITIAL INTENSITY REMAINS 65 KT BASED MAINLY ON THE CENTRAL
PRESSURE AND PERSISTENCE FROM THE PREVIOUS PACKAGE.

THE INITIAL MOTION IS A RATHER UNCERTAIN 055/8...UNCERTAIN BECAUSE
THE THE SHORT TERM MOTION SEEMS TO BE IN EXCESS OF 10 KT.  THE
REASON FOR THE ACCELERATION IS NOT CLEAR...BUT MAY BE RELATED TO
UPPER-LEVEL WESTERLY FLOW.  AS A TROUGH OVER THE WESTERN ATLANTIC
LIFTS OUT AND IS REPLACED BY RIDGING OVER THE EASTERN UNITED
STATES...OPHELIA IS EXPECTED TO SLOW AND LIKELY TURN BACK TOWARD
THE WEST OR WEST-NORTHWEST.  THIS TRACK IS SUPPORTED BY ALL THE
LARGE-SCALE MODELS EXCEPT THE GFS...WHICH CALLS FOR A SLOW
NORTHWARD MOTION AFTER 24 HR.  THE NEW FORECAST TRACK IS SIMILAR TO
THE PREVIOUS PACKAGE...CALLING FOR OPHELIA TO TURN BACK TO THE
WEST-NORTHWEST AND MAKE LANDFALL IN THE SOUTHEASTERN UNITED STATES
IN 72-96 HR.  THE NEW TRACK IS A LITTLE EAST AND NORTH OF THE
PREVIOUS TRACK BASED ON THE INITIAL POSITION.  IT SHOULD BE NOTED
THAT NONE OF THE LARGE-SCALE MODELS HAVE FORECAST THE CURRENT
MOTION...AND IF THE MOTION CONTINUES THE FORECAST TRACK WILL LIKELY
UNDERGO SOME ADJUSTMENTS IN LATER ADVISORIES.

THE INTENSITY FORECAST REMAINS PROBLEMATIC.  THE SHIPS...GFDL...AND
FSU SUPERENSEMBLE ALL FORECAST OPHELIA TO REACH 85 KT BEFORE
LANDFALL...AND THE INTENSITY FORECAST WILL FOLLOW SUIT.  THAT BEING
SAID...THE CURRENT SHEAR...ABUNDANT DRY AIR SEEN IN WATER VAPOR
IMAGERY...AND BROAD STORM STRUCTURE WILL LIKELY SLOW DEVELOPMENT. 
HOW LONG THE SHEAR WILL LAST IS UNCERTAIN...AS THE LARGE-SCALE
MODELS HAVE DIFFERING SOLUTIONS ON HOW THE UPPER-LEVEL WINDS WILL
EVOLVE NEAR OPHELIA.  AN EXTRA COMPLICATION IS THAT OPHELIA IS
FORECAST TO MOVE OVER SEA SURFACE TEMPERATURES OF 27-28C...EXCEPT
WHEN IT PASSES OVER THE GULF STREAM.  THE SLOW MOTION OVER
RELATIVELY SHALLOW WARM WATER MAY ALLOW THE STORM TO UPWELL COOLER
WATER AND INHIBIT INTENSIFICATION.  IT IS POSSIBLE THAT OPHELIA
COULD BECOME A CATEGORY THREE HURRICANE...BUT IT WOULD NOT BE A
SURPRISE IF IT STRENGTHENED LESS THAN CURRENTLY FORECAST.
 

 
FORECASTER BEVEN
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      10/0300Z 30.4N  77.0W    65 KT
 12HR VT     10/1200Z 31.0N  76.8W    65 KT
 24HR VT     11/0000Z 31.2N  76.7W    70 KT
 36HR VT     11/1200Z 31.5N  77.2W    75 KT
 48HR VT     12/0000Z 31.7N  77.9W    80 KT
 72HR VT     13/0000Z 32.5N  79.5W    85 KT
 96HR VT     14/0000Z 33.5N  80.0W    60 KT...INLAND
120HR VT     15/0000Z 35.5N  78.5W    30 KT...INLAND
 
 
$$
NNNN