Show Selection: |
#42418 (Received by flhurricane at: 10:52 PM 27.Aug.2005) TCDAT2 HURRICANE KATRINA DISCUSSION NUMBER 19 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 PM EDT SAT AUG 27 2005 REPORTS FROM AN AIR FORCE PLANE INDICATE THAT THE INTENSITY REMAINS ABOUT 100 KNOTS...BUT THE WIND FIELD IS EXPANDING. THE MINIMUM CENTRAL PRESSURE REPORTED THIS EVENING HAS BEEN 939 MB. THE SATELLITE PRESENTATION HAS BEEN UP AND DOWN...AND HAS BEEN CHANGING FROM A COIL TO A RING OF VERY DEEP CONVECTION THROUGHOUT THE EVENING. T-NUMBERS CONTINUE AROUND 5.5 ON THE DVORAK SCALE WHICH ALSO SUPPORTS 100 KNOTS. DATA FROM THE NOAA JET CURRENTLY SAMPLING THE ENVIRONMENT...INDICATE THAT THE CYCLONIC CIRCULATION EXTENDS UPWARD TO ABOUT 200 MB AND IT IS SURROUNDED BY A LARGE SCALE UPPER-LEVEL ANTICYLONE. THIS PATTERN...IN COMBINATION WITH THE HIGH OCEANIC HEAT CONTENT...FANCY WORDS FOR A WARM OCEAN...ALONG THE PATH OF KATRINA...CALLS FOR ADDITIONAL STRENGTHENING. THE STRENGTHENING IS ALSO FORECAST BY THE SHIPS AND THE GFDL MODELS WHICH BRING KATRINA TO 130 AND 123 KNOTS...RESPECTIVELY. CHANGES IN THE INNER CORE STRUCTURE BEFORE LANDFALL MAY MODIFY THE INTENSITY OF KATRINA UP OR DOWN...BUT UNFORTUNATELY...THESE CHANGES ARE NOT POSSIBLE TO FORECAST NOWADAYS WITH OUR PRESENT KNOWLEDGE. WE CAN ONLY DESCRIBE THEM AS THEY OCCUR. HOWEVER...DESPITE THESE CHANGES IN THE INNER CORE...THE BOTTOM LINE IS THAT KATRINA IS EXPECTED TO BE AN INTENSE AND DANGEROUS HURRICANE HEADING TOWARD THE NORTH CENTRAL GULF COAST...AND THIS HAS TO BE TAKEN VERY SERIOUSLY. IT APPEARS THAT KATRINA HAS BEGUN TO MOVE TOWARD THE WEST-NORTHWEST OR 290 DEGREES AT 6 KNOTS AS THE HIGH TO THE NORTHWEST OF THE HURRICANE BEGINS TO RETREAT WESTWARD AND LEAVES A WEAKNESS OVER THE CENTRAL GULF OF MEXICO. THE COMBINATION OF BUILDING HIGH PRESSURE OVER THE WESTERN NORTH ATLANTIC...AND A WEAK TROUGH APPROACHING THE GULF OF MEXICO FROM THE NORTHWEST...SHOULD RESULT IN A PATTERN THAT FORCES KATRINA TO TURN NORTHWESTWARD AND NORTHWARD TOWARD THE CENTRAL GULF COAST. THIS IS ALSO THE SOLUTION PROVIDED BY THE GLOBAL MODEL CONSENSUS WHICH THE OFFICIAL FORECAST FOLLOWS VERY CLOSELY. FORECASTER AVILA FORECAST POSITIONS AND MAX WINDS INITIAL 28/0300Z 25.0N 86.2W 100 KT 12HR VT 28/1200Z 25.4N 87.3W 110 KT 24HR VT 29/0000Z 27.0N 89.0W 120 KT 36HR VT 29/1200Z 29.0N 89.8W 125 KT 48HR VT 30/0000Z 31.0N 89.8W 85 KT...INLAND 72HR VT 31/0000Z 36.5N 87.0W 40 KT...INLAND 96HR VT 01/0000Z 41.0N 80.5W 30 KT...BECOMING EXTRATROPICAL 120HR VT 02/0000Z 45.5N 71.4W 25 KT...EXTRATROPICAL |