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| #222228 (Received by flhurricane at: 4:46 AM 15.Oct.2008) TCDAT5 HURRICANE OMAR DISCUSSION NUMBER 8 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL152008 500 AM EDT WED OCT 15 2008 AN AIR FORCE HURRICANE HUNTER AIRCRAFT REPORTS THAT THERE HAS BEEN NO APPRECIABLE STRENGTHENING OF OMAR OVER THE PAST FEW HOURS. AN ELLIPTICAL AND PARTIALLY OPEN EYE WAS OBSERVED BUT THE INNER CORE IS NOT YET WELL-DEFINED. THE CENTRAL PRESSURE HAS NOT FALLEN AND MAXIMUM SFMR-OBSERVED SURFACE WIND SPEEDS HAVE BEEN NEAR 65 KT...WHICH IS USED FOR THE ADVISORY INTENSITY. SATELLITE IMAGES SHOW THAT OMAR CONTINUES TO GENERATE VERY DEEP CONVECTION WITH A LARGE AREA OF CLOUD TOPS COLDER THAN -80 DEG C. UPPER-LEVEL OUTFLOW IS WELL-ESTABLISHED OVER THE EASTERN SEMICIRCLE AND RESTRICTED TO THE WEST...AS WESTERLY SHEAR CONTINUES TO IMPACT THE HURRICANE. HOWEVER...THE SHEAR IS NOT EXPECTED TO BE STRONG ENOUGH TO PREVENT STRENGTHENING. THE OFFICIAL INTENSITY FORECAST IS THE SAME AS THE PREVIOUS ONE AND A LITTLE ABOVE THE MODEL CONSENSUS. BY DAY 5...GLOBAL MODELS DEPICT THE CYCLONE INTERACTING WITH A STRONG BAROCLINIC ZONE OVER THE NORTH ATLANTIC SO THE OFFICIAL FORECAST SHOWS OMAR BECOMING EXTRATROPICAL BY THAT TIME. INITIAL MOTION IS AROUND 050/6. THERE HAS NOT BEEN MUCH CHANGE TO THE OFFICIAL FORECAST TRACK OR REASONING. A MID-LEVEL TROUGH TO THE NORTH OF THE HURRICANE ALONG WITH A RIDGE TO THE EAST IS CREATING A SOUTHWESTERLY STEERING CURRENT AND OMAR IS EXPECTED TO CONTINUE NORTHEASTWARD WITH A GRADUAL INCREASE IN FORWARD SPEED. THE FORWARD MOTION SLOWS A LITTLE AROUND DAY 3 AS THE TROUGH LIFTS OUT AHEAD OF OMAR. THE SYSTEM SHOULD ACCELERATE AGAIN NEAR THE END OF THE PERIOD AS IT ENCOUNTERS THE MAIN BRANCH OF THE MID-LATITUDE WESTERLIES. DYNAMICAL TRACK PREDICTION MODELS ARE TIGHTLY CLUSTERED...ESPECIALLY FOR THE FIRST 24 HOURS AND THE OFFICIAL FORECAST IS CLOSE TO THE MODEL CONSENSUS ALBEIT A LITTLE SLOWER. THIS IS SLIGHTLY FASTER THAN THE PREVIOUS FORECAST...BUT MORE OR LESS ALONG THE SAME TRAJECTORY. ALTHOUGH THE OFFICIAL FORECAST KEEPS THE CENTER EAST OF PUERTO RICO...A DEVIATION TO THE LEFT OF THE CURRENT MOTION COULD REQUIRE CHANGING THE HURRICANE WATCH TO A HURRICANE WARNING FOR THAT ISLAND. FORECAST POSITIONS AND MAX WINDS INITIAL 15/0900Z 14.6N 67.7W 65 KT 12HR VT 15/1800Z 15.8N 66.5W 75 KT 24HR VT 16/0600Z 18.0N 64.5W 85 KT 36HR VT 16/1800Z 20.8N 62.2W 90 KT 48HR VT 17/0600Z 23.8N 60.2W 90 KT 72HR VT 18/0600Z 29.0N 57.0W 80 KT 96HR VT 19/0600Z 35.0N 51.0W 70 KT 120HR VT 20/0600Z 43.0N 37.0W 60 KT...EXTRATROPICAL $$ FORECASTER PASCH |
