[Tropical] Tropical Cyclone Discussion

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WTNT41 KNHC 022043
TCDAT1

HURRICANE OPHELIA DISCUSSION NUMBER  41
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL162011
500 PM AST SUN OCT 02 2011

ALTHOUGH THE CLOUD PATTERN OF OPHELIA HAS GRADUALLY DEGRADED IN
CONVENTIONAL SATELLITE IMAGERY TODAY...A RECENT AMSR-E MICROWAVE
IMAGE SHOWED THAT THE INNER-CORE STRUCTURE REMAINS INTACT. THE EYE
HAS BECOME LARGER...BUT REMAINS CLOSED. THE MICROWAVE DATA CONTINUE
TO SUGGEST THAT THE CIRCULATION IS TILTED...WITH THE SURFACE CENTER
LOCATED TO THE SOUTHWEST OF MID-LEVEL EYE AND ROTATION SEEN IN
VISIBLE SATELLITE PICTURES. DVORAK T-NUMBERS ARE GRADUALLY
DECREASING AND THE INITIAL INTENSITY IS LOWERED TO 85 KT. OPHELIA
IS CURRENTLY TRAVERSING THE NORTH WALL OF THE GULF STREAM AND WILL
BE MOVING OVER MUCH COLDER WATERS DURING THE NEXT DAY OR SO. THE
COLD WATER AND INCREASING SOUTHWESTERLY SHEAR SHOULD CAUSE RAPID
WEAKENING TONIGHT AND MONDAY. OPHELIA WILL ALSO INTERACT WITH A
FRONTAL BOUNDARY AND IS FORECAST TO BECOME AN EXTRATROPICAL CYCLONE
WITHIN 24 HOURS.

THE INITIAL MOTION ESTIMATE IS 015/29 KT. THE TRACK FORECAST
REASONING REMAINS UNCHANGED FROM THE PREVIOUS ADVISORY. THE
HURRICANE IS FORECAST TO TURN NORTHEASTWARD LATER TONIGHT AND PASS
NEAR OR OVER THE AVALON PENINSULA OF NEWFOUNDLAND BY EARLY MONDAY
MORNING. AFTER THAT...THE CYCLONE IS EXPECTED TO TURN NORTH-
NORTHEAST IN THE MID-LATITUDE WESTERLY FLOW OVER THE NORTH ATLANTIC
AND BE ABSORBED BY A COLD FRONT IN 2 TO 3 DAYS. THE TRACK GUIDANCE
IS IN GOOD AGREEMENT ON THIS SCENARIO. THE NEW NHC FORECAST HAS
BEEN SHIFTED SLIGHTLY WEST OF THE PREVIOUS FORECAST AT 12 AND 24
HOURS TO BE CLOSER TO THE GFS AND ECMWF MODELS.

THE TROPICAL STORM FORCE WIND RADII OVER THE EASTERN PORTION OF THE
CIRCULATION HAVE BEEN EXPANDED BASED ON RECENT ASCAT AND SHIP DATA.


FORECAST POSITIONS AND MAX WINDS

INIT  02/2100Z 41.6N  59.9W   85 KT 100 MPH
 12H  03/0600Z 45.2N  56.6W   65 KT  75 MPH
 24H  03/1800Z 48.6N  48.2W   50 KT  60 MPH...POST-TROP/EXTRATROP
 36H  04/0600Z 51.0N  37.5W   40 KT  45 MPH...POST-TROP/EXTRATROP
 48H  04/1800Z 56.0N  25.5W   35 KT  40 MPH...POST-TROP/EXTRATROP
 72H  05/1800Z...ABSORBED BY FRONT

$$
FORECASTER BROWN



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