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| #150821 (Received by flhurricane at: 4:25 PM 14.Sep.2007) TCDAT3 TROPICAL STORM INGRID DISCUSSION NUMBER 10 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL082007 500 PM EDT FRI SEP 14 2007 THE ANTICIPATED ARRIVAL OF THE UPPER-LEVEL WESTERLIES OVER INGRID HAS MATERIALIZED AND THE CONVECTIVE PATTERN HAS BECOME BASICALLY SHAPELESS WITH NO OUTFLOW. HOWEVER...THE CYCLONE IS MAINTAINING A WELL-DEFINED LOW-LEVEL CIRCULATION WITH TRANSIENT BURSTS OF DEEP CONVECTION NEAR THE CENTER. GIVEN THE CURRENT DETERIORATION OF THE CLOUD PATTERN...THE INITIAL INTENSITY IS LOWERED TO 35 KNOTS WHICH IS CONSISTENT WITH THE DECREASE IN DVORAK T-NUMBERS. MOST OF THE GLOBAL MODELS FORECAST A PLAGUE OF UPPER-LEVEL WESTERLIES OVER INGRID THROUGH 5 DAYS ASSOCIATED WITH A STRONGER THAN NORMAL MID-OCEANIC TROUGH. THIS PERSISTENT PATTERN WILL LIKELY CONTINUE TO SHRED THE CLOUD PATTERN...RESULTING IN ADDITIONAL WEAKENING AS INDICATED IN THE OFFICIAL FORECAST. I AM SURPRISED THAT SOME MODELS MAINTAIN THE CYCLONE OR EVEN FORECAST STRENGTHENING...DESPITE THE HOSTILE ENVIRONMENT. IN FACT...ONLY THE GFS AND THE GFDL BASICALLY WEAKEN INGRID. INGRID IS MOVING ON A SLOW NORTHWESTWARD TRACK OR 305 DEGREES AT 6 KNOTS. THE CYCLONE SHOULD CONTINUE ON THIS GENERAL SLOW TRACK... WHILE EMBEDDED WITHIN LIGHT STEERING CURRENTS WHICH PREVAIL TO THE SOUTH OF A WEAK RIDGE OF HIGH PRESSURE. THE CYCLONE SHOULD TURN MORE TO THE NORTH-NORTHWEST AS A MID-LEVEL TROUGH DIGS IN THE CENTRAL ATLANTIC. THE OFFICIAL FORECAST IS VERY CLOSE TO THE CONSENSUS AND KEEPS THE CYCLONE OVER OPEN WATERS WELL NORTH OF THE LEEWARD ISLANDS. FORECAST POSITIONS AND MAX WINDS INITIAL 14/2100Z 15.6N 50.6W 35 KT 12HR VT 15/0600Z 16.0N 51.5W 35 KT 24HR VT 15/1800Z 17.0N 52.8W 30 KT 36HR VT 16/0600Z 18.0N 54.0W 30 KT 48HR VT 16/1800Z 19.0N 55.3W 30 KT 72HR VT 17/1800Z 20.5N 57.0W 30 KT 96HR VT 18/1800Z 22.0N 58.9W 30 KT 120HR VT 19/1800Z 24.0N 61.0W 30 KT $$ FORECASTER AVILA |
