000 WTNT43 KNHC 160859 TCDAT3 TROPICAL STORM KARL DISCUSSION NUMBER 7 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL132010 400 AM CDT THU SEP 16 2010 THE CENTER OF KARL EMERGED INTO THE BAY OF CAMPECHE BETWEEN 0330 AND 0400 UTC AFTER MAINTAINING AN IMPRESSIVE CONVECTIVE STRUCTURE OVER LAND...WITH AN EYE-LIKE FEATURE INTERMITTENTLY SEEN IN INFRARED IMAGERY OVER THE PAST FEW HOURS. DVORAK INTENSITY ESTIMATES WERE 3.5/55 KT FROM TAFB AND SAB. FOR THIS ADVISORY THE INITIAL INTENSITY IS INCREASED TO 45 KT BASED ON THE ASSUMPTION THAT THE WIND FIELD WILL TAKE SOME TIME TO SPIN UP AFTER MOVING OVER WATER. KARL SEEMS POISED TO TAKE ADVANTAGE OF THE FAVORABLE ENVIRONMENT OF VERY WARM WATERS AND LOW SHEAR OVER THE BAY OF CAMPECHE. ALSO... GIVEN THE SLOWER FORWARD SPEED OF THE TRACK GUIDANCE...KARL WILL LIKELY HAVE MORE TIME OVER WATER BEFORE MAKING LANDFALL IN MEXICO. THEREFORE...THE OFFICIAL FORECAST HAS BEEN ADJUSTED UPWARD FROM THE PREVIOUS PACKAGE AND SHOWS A PEAK INTENSITY OF 75 KT AROUND THE TIME OF LANDFALL...IN BEST AGREEMENT WITH THE SHIPS GUIDANCE. THE INITIAL MOTION IS 290/11 KT. KARL WILL REMAIN TO THE SOUTH OF A STRONG MID-LEVEL RIDGE THAT WILL RETROGRADE FROM THE NORTHERN GULF COAST TO THE SOUTH-CENTRAL UNITED STATES OVER THE NEXT COUPLE OF DAYS. THIS WILL STEER KARL WILL TOWARD THE WEST-NORTHWEST OR WEST OVER THE SOUTHERN GULF OF MEXICO FOR THE NEXT COUPLE OF DAYS...AND BRING THE CYCLONE TO THE COAST OF MEXICO WITHIN THE HURRICANE WATCH AREA LATE FRIDAY OR EARLY SATURDAY. WHILE THE MODELS REMAIN IN AGREEMENT ON THIS OVERALL SCENARIO...MUCH OF THE GUIDANCE FOR THIS CYCLE...WITH THE EXCEPTION OF THE UKMET AND THE ECMWF...HAS SLOWED AND SHIFTED SOUTH. THE OFFICIAL FORECAST HAS BEEN ADJUSTED IN THAT DIRECTION AND LIES BETWEEN THE UKMET AND ECMWF MODELS AND THE TVCN MULTI-MODEL CONSENSUS. GIVEN THE SOUTHWARD SHIFT IN THE TRACK... THE HURRICANE WATCH HAS BEEN EXTENDED SOUTHWARD TO PALMA SOLA. FORECAST POSITIONS AND MAX WINDS INITIAL 16/0900Z 19.8N 91.6W 45 KT 12HR VT 16/1800Z 20.3N 93.0W 55 KT 24HR VT 17/0600Z 20.7N 94.7W 60 KT 36HR VT 17/1800Z 21.0N 96.1W 70 KT 48HR VT 18/0600Z 21.1N 97.4W 75 KT...INLAND 72HR VT 19/0600Z 21.0N 100.5W 35 KT...INLAND 96HR VT 20/0600Z 21.0N 103.0W 20 KT...DISSIPATING INLAND 120HR VT 21/0600Z...DISSIPATED $$ FORECASTER BRENNAN