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#42206 (Received by flhurricane at: 10:49 PM 26.Aug.2005) TCDAT2 HURRICANE KATRINA DISCUSSION NUMBER 15 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 PM EDT FRI AUG 26 2005 THE SATELLITE PRESENTATION HAS CONTINUED TO IMPROVE AND CONSISTS OF A PERFECT A COMMA-SHAPED CLOUD PATTERN WHICH BEGINS OVER WESTERN CUBA AND WRAPS AROUND A LARGE CLUSTER OF VERY DEEP CONVECTION. THIS BAND IS PROBABLY PRODUCING NEAR TROPICAL STORM FORCE WINDS ALONG THE NORTH COAST OF WESTERN CUBA. ALTHOUGH THE EYE IS NOT CLEARLY VISIBLE ON IR IMAGES...RADAR DATA INDICATE THAT THE EYE IS EMBEDDED WITHIN THIS CIRCULAR AREA OF DEEP CONVECTION. T-NUMBERS FROM SAB AND TAFB HAVE INCREASED TO 5.0 ON THE DVORAK SCALE. THEREFORE... THE INITIAL INTENSITY HAS BEEN ADJUSTED TO 90 KNOTS. AN AIR FORCE RECONNAISSANCE PLANE IS SCHEDULED TO BE IN KATRINA IN THE NEXT FEW HOURS. THE HURRICANE IS EXPECTED TO BE UNDER A TYPICAL 200 MB ANTICYLONE...WITH A CYCLONIC CIRCULATION EXTENDING UPWARD TO THAT LEVEL. THIS IS THE TYPICAL PATTERN OBSERVED IN INTENSE HURRICANES. IN ADDITION...KATRINA IS FORECAST TO MOVE DIRECTLY OVER THE WARM LOOP CURRENT OF THE GULF OF MEXICO...WHICH IS LIKE ADDING HIGH OCTANE FUEL TO THE FIRE. THEREFORE...THE OFFICIAL FORECAST BRINGS KATRINA TO 115 KNOTS...OR A CATEGORY FOUR ON THE SAFFIR-SIMPSON HURRICANE SCALE. THE GFDL IS MORE AGGRESSIVE AND CALLS FOR 124 KNOTS AND 922 MB. THE FSU SUPERENSEMBLE IS EVEN MORE AGGRESSIVE BRINGING KATRINA TO 131 KNOTS. KATRINA CONTINUES TO MOVE STUBBORNLY TOWARD THE WEST-SOUTHWEST OR 250 DEGREES AT 7 KNOTS ALONG THE EASTERN SIDE OF A VERY STRONG DEEP-LAYER MEAN HIGH CENTERED OVER TEXAS. IN FACT...DATA FROM THE NOAA JET JUST RELAYED BY THE METEOROLOGIST ONBOARD INDICATE THAT THE HIGH CONTINUES TO BE VERY STRONG. HOWEVER...THIS FEATURE IS EXPECTED TO MOVE WESTWARD AND LEAVE A WEAKNESS OVER THE CENTRAL GULF OF MEXICO. KATRINA WILL LIKELY TAKE THAT OPPORTUNITY AND BEGIN TO TURN GRADUALLY TOWARD THE WEST-NORTHWEST AND THEN NORTHWARD. THE OFFICIAL FORECAST BRINGS THE CORE OF THE INTENSE HURRICANE OVER THE NORTH CENTRAL GULF OF MEXICO IN 48 HOURS OR SO. IT IS WORTH NOTING THAT THE GUIDANCE SPREAD HAS DECREASED AND MOST OF THE RELIABLE NUMERICAL MODEL TRACKS ARE NOW CLUSTERED BETWEEN THE EASTERN COAST OF LOUISIANA AND THE COAST OF MISSISSIPPI. THIS CLUSTERING INCREASES THE CONFIDENCE IN THE FORECAST. FORECASTER AVILA FORECAST POSITIONS AND MAX WINDS INITIAL 27/0300Z 24.6N 83.6W 90 KT 12HR VT 27/1200Z 24.6N 84.6W 100 KT 24HR VT 28/0000Z 25.0N 86.0W 115 KT 36HR VT 28/1200Z 26.0N 87.5W 115 KT 48HR VT 29/0000Z 27.0N 89.0W 115 KT 72HR VT 30/0000Z 30.5N 89.5W 115 KT 96HR VT 31/0000Z 35.0N 87.5W 35 KT...INLAND 120HR VT 01/0000Z 40.5N 81.0W 25 KT...BECOMING EXTRATROPICAL |