|
Show Selection: |
| #45312 (Received by flhurricane at: 10:52 AM 11.Sep.2005) TCDAT1 HURRICANE OPHELIA DISCUSSION NUMBER 21 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 AM EDT SUN SEP 11 2005 AIR FORCE RECONNAISSANCE OBSERVATIONS OVER THE LAST FEW HOURS SHOWED MAXIMUM FLIGHT-LEVEL WINDS OF 74 KT...WITH LITTLE CHANGE IN CENTRAL PRESSURE. THE CURRENT INTENSITY IS REDUCED SLIGHTLY...TO 70 KT. THE SYSTEM APPEARS WELL ORGANIZED AND VERTICAL SHEAR IS NOT EXPECTED TO BECOME PROHIBITIVELY STRONG DURING THE NEXT FEW DAYS. TWO FACTORS MITIGATING AGAINST INTENSIFICATION ARE THE PRESENCE OF DRY AIR...AS EVIDENCED BY SURFACE OBSERVATIONS FROM SOUTH CAROLINA AND NORTH CAROLINA SHOWING DEW POINTS IN THE LOW SIXTIES...AND COOLER WATERS UPWELLED BENEATH THIS SLOW-MOVING HURRICANE. OPHELIA IS LIKELY TO TRAVERSE A SECTION OF THE GULF STREAM OVER THE NEXT FEW DAYS... HOWEVER...WHICH WOULD FAVOR SOME INTENSIFICATION. GIVEN THESE MIXED SIGNALS...THE OFFICIAL FORECAST DOES NOT CALL FOR A SIGNIFICANT CHANGE IN STRENGTH. THIS IS VERY SIMILAR TO THE LATEST SHIPS FORECAST AS WELL. OPHELIA CONTINUES STUCK BETWEEN TWO MID-LEVEL HIGH PRESSURE AREAS...AND UNABLE TO MAKE CONTACT WITH THE WESTERLIES. LITTLE CHANGE IN THIS STEERING...OR LACK OF STEERING...REGIME IS LIKELY FOR THE NEXT DAY OR TWO. BY AROUND 72 HOURS...GLOBAL MODEL GUIDANCE SHOWS A LARGE MID-LATITUDE TROUGH ADVANCING INTO THE CENTRAL UNITED STATES. THIS FEATURE SHOULD BREAK DOWN THE BLOCKING HIGH TO THE NORTHWEST OF THE HURRICANE AND ALLOW OPHELIA TO BEGIN MOVING ON A NORTH-NORTHWESTWARD OR NORTHWARD HEADING. THE LATEST GFS RUN HAS SHIFTED A LITTLE TO THE WEST OF THE PREVIOUS ONE AT DAYS 3-5...BUT THE NEW NOGAPS RUN HAS SHIFTED A LITTLE TO THE EAST. THE OFFICIAL FORECAST TAKES THE TROPICAL CYCLONE OVER/NEAR EASTERN NORTH CAROLINA IN ABOUT 3 DAYS...AND IS VERY SIMILAR TO THE FORECAST FROM THE PREVIOUS ADVISORY. IT SHOULD BE ADDED THAT 3-DAY TRACK FORECASTS CAN EASILY BE IN ERROR BY 200 NAUTICAL MILES. NO ADJUSTMENTS ARE MADE TO THE HURRICANE WATCH AREA AT THIS TIME SINCE THERE HAS BEEN LITTLE MOVEMENT...AND THE FORECAST TRACK THROUGH 72 HOURS HAS NOT CHANGED. FORECASTER PASCH FORECAST POSITIONS AND MAX WINDS INITIAL 11/1500Z 31.6N 75.7W 70 KT 12HR VT 12/0000Z 31.6N 75.7W 70 KT 24HR VT 12/1200Z 31.9N 76.1W 75 KT 36HR VT 13/0000Z 32.2N 76.5W 75 KT 48HR VT 13/1200Z 32.7N 76.7W 75 KT 72HR VT 14/1200Z 34.5N 76.5W 75 KT 96HR VT 15/1200Z 37.5N 74.5W 50 KT 120HR VT 16/1200Z 40.5N 71.0W 40 KT |
