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#90656 (Received by flhurricane at: 8:55 AM 10.Jun.2006) TCDAT1 TROPICAL DEPRESSION ONE SPECIAL DISCUSSION NUMBER 1 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL012006 800 AM CDT SAT JUN 10 2006 SURFACE OBSERVATIONS...SATELLITE IMAGERY...AND RADAR DATA FROM WESTERN CUBA INDICATE THAT THE AREA OF LOW PRESSURE OVER THE NORTHWESTERN CARIBBEAN SEA HAS ORGANIZED INTO A TROPICAL DEPRESSION. THE ELONGATED LOW-LEVEL CENTER IS PARTLY EXPOSED TO THE WEST OF A LARGE CONVECTIVE AREA WITH TOPS TO -85C. SATELLITE AND RADAR DATA SHOW AT LEAST TWO SMALL-SCALE VORTICITY CENTERS EMBEDDED WITHIN THE LARGER CIRCULATION...WITH THE ADVISORY POSITION BEING THAT OF THE OVERALL MEAN CENTER. THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 340/10. THE DEPRESSION IS ON THE EAST SIDE OF A MID/UPPER-LEVEL LOW CENTERED OVER THE SOUTHERN GULF OF MEXICO. IN THE SHORT TERM...THIS SYSTEM SHOULD STEER THE DEPRESSION GENERALLY NORTH-NORTHWESTWARD TOWARD A COL AREA BETWEEN THE UPPER LOW...A LARGE MID/UPPER-LEVEL RIDGE OVER THE CENTRAL AND WESTERN UNITED STATES...AND A LARGE MID/UPPER-LEVEL TROUGH OVER THE EASTERN UNITED STATES. LARGE-SCALE GUIDANCE SHOWS SEVERAL POSSIBLE SCENARIOS. THE GFS AND GFDL RECURVE THE CYCLONE NORTHEASTWARD INTO THE TROUGH...WHILE THE CANADIAN AND STALLS THE SYSTEM OVER THE NORTHERN GULF OF MEXICO. THE NOGAPS AND ECMWF MODELS SPLIT THE DEPRESSION INTO MULTIPLE LOWS...WHILE THE UKMET TURNS IT WESTWARD TOWARD TEXAS. THE TRACK FORECAST WILL FOLLOW THE RECURVATURE SCENARIO AND BRING THE CENTER ACROSS THE FLORIDA PENINSULA IN ABOUT 72 HR. HOWEVER...THERE IS A GREATER THAN NORMAL AMOUNT OF UNCERTAINTY IN THIS FORECAST. THE LARGE-SCALE MODELS AGREE THAT THE CYCLONE WILL BECOME EMBEDDED IN MODERATE TO STRONG UPPER-LEVEL WESTERLIES BETWEEN THE U. S. TROUGH AND A LARGE UPPER-LEVEL ANTICYCLONE OVER THE CARIBBEAN. THIS SHOULD PRODUCE PERSISTENT MODERATE TO STRONG VERTICAL WIND SHEAR THAT SHOULD LIMIT INTENSIFICATION. THE INTENSITY FORECAST CALLS FOR THE INTENSITY TO REACH 50 KT BEFORE LANDFALL IN BEST AGREEMENT WITH THE GFDL MODEL. IF THE CYCLONE FOLLOWS THE FORECAST TRACK...INTERACTION WITH THE TROUGH SHOULD CAUSE EXTRATROPICAL TRANSITION OVER THE WESTERN ATLANTIC. FORECASTER BEVEN FORECAST POSITIONS AND MAX WINDS INITIAL 10/1300Z 21.1N 85.3W 30 KT 12HR VT 10/1800Z 22.0N 85.7W 35 KT 24HR VT 11/0600Z 23.9N 86.7W 40 KT 36HR VT 11/1800Z 25.6N 86.9W 45 KT 48HR VT 12/0600Z 27.2N 86.1W 50 KT 72HR VT 13/0600Z 29.5N 82.5W 50 KT...INLAND 96HR VT 14/0600Z 34.0N 77.0W 45 KT...BECOMING EXTRATROPICAL 120HR VT 15/0600Z 42.0N 67.0W 45 KT...EXTRATROPICAL |