| HOME | ARCHIVES | FORECASTS | IMAGERY | ABOUT NHC | RECONNAISSANCE |

---

Hurricane OPHELIA (Text)

ZCZC MIATCDAT1 ALL
TTAA00 KNHC DDHHMM
HURRICANE OPHELIA DISCUSSION NUMBER  38
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 AM EDT THU SEP 15 2005
 
OPHELIA HAS BECOME RAGGED LOOKING IN RADAR IMAGERY... AND WIND DATA
FROM BOTH COASTAL DOPPLER RADARS AND AN AIR FORCE RECONNAISSANCE
AIRCRAFT INDICATE THAT MAXIMUM SUSTAINED WINDS HAVE DECREASED TO 70
KT...WHICH MAY BE A LITTLE GENEROUS. THE CENTRAL PRESSURE HAS ALSO
INCREASED 4 MB...NOW 986 MB...DURING THE PAST 6 HOURS.

THE INITIAL MOTION ESTIMATE IS 065/03. OPHELIA HAS SLOWED DOWN AND
HAS PERHAPS EVEN STALLED AS THE CYCLONE IS...ONCE AGAIN... CAUGHT
BETWEEN TWO RIDGES. THE LARGE-SCALE RIDGE TO THE EAST THAT EXTENDS
NORTHWARD FROM BERMUDA TO NOVA SCOTIA IS FORECAST TO MOVE SLOWLY
EASTWARD... WHILE THE SHORTWAVE RIDGE LOCATED TO THE WEST FROM
GEORGIA NORTHWARD TO OHIO IS EXPECTED TO CONTINUE TO SLOWLY WEAKEN
AND GIVE WAY TO INCREASING WEST-SOUTHWESTERLY MID-LEVEL FLOW AHEAD
OF AN APPROACHING SHORTWAVE TROUGH. THE OVERALL LARGE-SCALE FLOW
PATTERN IS CURRENTLY MORE ZONAL THAN MERIDIONAL AND THIS
PROGRESSIVE PATTERN IS EXPECTED TO PERSIST THROUGHOUT THE FORECAST
PERIOD...WHICH SHOULD KEEP OPHELIA MOVING PARALLEL TO THE U.S. EAST
COAST. THE 06Z NHC MODEL GUIDANCE HAS MADE A LITTLE MORE OF A
WESTWARD SHIFT AFTER 48 HOURS...AND SOME OF THE MODELS LIKE NOGAPS
AND UKMET BRING OPHELIA OVER OR VERY CLOSE THE NEW ENGLAND AREA.
HOWEVER...THE GFDL...GFS...AND CANADIAN MODELS KEEP OPHELIA WELL TO
THE EAST OF THE NORTHEASTERN UNITED STATES...WHICH SEEMS MORE
REASONABLE GIVEN THE LOW AMPLITUDE FLOW PATTERN NOTED IN THE 12Z
UPPER-AIR DATA AND WATER VAPOR IMAGERY. THE OFFICIAL FORECAST TRACK
IS SIMILAR TO THE PREVIOUS FORECAST...ONLY SLOWER DURING THE FIRST
48 HOURS. 
 
EXCEPT FOR THE EXCELLENT UPPER-LEVEL OUTFLOW PATTERN...NOT MUCH ELSE
IS FAVORABLE FOR ANY INTENSIFICATION TO OCCUR. A SIGNIFICANT AMOUNT
OF DRY MID-LEVEL AIR HAS INTRUDED FROM THE WEST...WHICH HAS HELPED
TO ERODE THE CONVECTION ON THE WEST SIDE OF OPHELIA. COOL SHELF
WATER JUST OFFSHORE THE OUTER BANKS IS ALSO HELPING TO STABILIZE
THE ATMOSPHERE ON THE WEST SIDE AND WEAKEN THE CONVECTION. HOWEVER
...OPHELIA IS STILL CLOSE ENOUGH TO THE GULFSTREAM TO TAP INTO THE
WARMER 82-83F WATER THAT EXISTS THERE...SO ONLY SLOW WEAKENING IS
FORECAST UNTIL 48 HOURS WHEN INCREASING VERTICAL SHEAR AND MUCH
COOLER WATER ARE EXPECTED TO ENHANCE THE TRANSITION INTO AN
EXTRATROPICAL LOW PRESSURE SYSTEM.
 
FORECASTER STEWART
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      15/1500Z 34.8N  75.7W    70 KT
 12HR VT     16/0000Z 35.0N  75.0W    65 KT
 24HR VT     16/1200Z 35.7N  74.3W    65 KT
 36HR VT     17/0000Z 37.1N  73.2W    60 KT
 48HR VT     17/1200Z 39.2N  70.9W    55 KT
 72HR VT     18/1200Z 44.2N  63.2W    50 KT...EXTRATROPICAL
 96HR VT     19/1200Z 47.0N  56.0W    45 KT...EXTRATROPICAL
120HR VT     20/1200Z 51.0N  40.0W    45 KT...EXTRATROPICAL
 
$$
NNNN