000 WTNT42 KNHC 282100 TCDAT2 TROPICAL STORM GUSTAV DISCUSSION NUMBER 16 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072008 500 PM EDT THU AUG 28 2008 THE CENTER OF GUSTAV MADE LANDFALL ALONG THE EASTERN TIP OF JAMAICA AT ABOUT 1800 UTC TODAY...BASED ON FLIGHT-LEVEL WIND DATA FROM AN AIR FORCE RECONNAISSANCE AIRCRAFT THAT WAS ABLE TO FLY THROUGH THE CENTER NEAR THAT TIME. FLIGHT-LEVEL WIND SPEEDS INDICATED THAT GUSTAV WAS RIGHT NEAR THE THRESHOLD BETWEEN TROPICAL STORM AND HURRICANE INTENSITY...BUT THE DATA WERE NOT QUITE CONVINCING ENOUGH TO INCREASE THE INTENSITY WHICH REMAINS 60 KT. THE AIRCRAFT SUBSEQUENTLY DETECTED THE CENTER LOCATED INLAND OVER THE EASTERN PORTION OF THE ISLAND. A LITTLE WEAKENING IS FORECAST IN THE SHORT TERM AS GUSTAV INTERACTS WITH LAND...BUT ONCE IT EMERGES OVER THE OPEN WATERS OF THE NORTHWESTERN CARIBBEAN BY TOMORROW...CONDITIONS APPEAR RATHER FAVORABLE FOR STRENGTHENING. DUE TO THE VERY WARM WATERS SOUTH OF CUBA...COMBINED WITH ANTICYCLONIC FLOW ALOFT...IT IS POSSIBLE THAT GUSTAV COULD RAPIDLY INTENSIFY AT SOME POINT WITHIN THE NEXT COUPLE OF DAYS...ALTHOUGH THAT IS NOT EXPLICITLY SHOWN IN THE OFFICIAL FORECAST. CONDITIONS OVER THE GULF ARE NOT FORECAST TO BE PROHIBITIVE FOR STRENGTHENING EITHER...SO GUSTAV COULD REACH MAJOR HURRICANE STATUS WITHIN A FEW DAYS...AS FORECAST BY ESSENTIALLY ALL AVAILABLE INTENSITY GUIDANCE. GUSTAV IS RESPONDING TO THE MID-LEVEL RIDGE TO ITS NORTH BY CONTINUING WESTWARD AT ABOUT 275/5. A WEAKNESS DEVELOPING IN THAT RIDGE OVER THE EASTERN GULF OF MEXICO DURING THE NEXT DAY OR TWO SHOULD IMPART A GRADUAL RIGHT TURN ACROSS THE NORTHWESTERN CARIBBEAN AND GENERALLY INTO THE CENTRAL GULF. TRACK MODEL GUIDANCE IS MOSTLY IN GOOD AGREEMENT ON A TRACK NEAR OR OVER THE WESTERNMOST PROVINCES OF CUBA IN A COUPLE OF DAYS. THE MODEL SPREAD INCREASES OVER THE GULF...HOWEVER...BOTH IN TERMS OF PATH AND FORWARD SPEED...BOUNDED BY THE FAST GFDL ON THE RIGHT AND A MUCH SLOWER GFS ON THE LEFT. DESPITE SOME CHANGES IN THE INDIVIDUAL MODEL TRACKS...THE CONSENSUS HAS BARELY BUDGED AND THE NEW OFFICIAL TRACK FORECAST IS VERY SIMILAR TO THE PREVIOUS ONE. SINCE TRACK FORECASTS ARE ALWAYS SUBJECT TO LARGE ERRORS AT 3-5 DAYS...AND ESPECIALLY GIVEN THE NOTABLE MODEL SPREAD OVER THE GULF OF MEXICO...IT IS SIMPLY IMPOSSIBLE TO DETERMINE EXACTLY WHERE AND WHEN GUSTAV WILL MAKE FINAL LANDFALL. IN FACT...TAKING INTO ACCOUNT THE UNCERTAINTIES IN TRACK...INTENSITY...AND SIZE FORECASTS...THE CHANCES OF HURRICANE-FORCE WINDS WITHIN THE NEXT FIVE DAYS ARE ESSENTIALLY THE SAME AT EACH INDIVIDUAL LOCATION FROM THE FLORIDA PANHANDLE COAST WESTWARD THROUGH THE ENTIRE COASTLINE OF LOUISIANA. FORECAST POSITIONS AND MAX WINDS INITIAL 28/2100Z 18.1N 76.6W 60 KT 12HR VT 29/0600Z 18.4N 77.8W 55 KT...INLAND OVER JAMAICA 24HR VT 29/1800Z 19.1N 79.7W 70 KT 36HR VT 30/0600Z 20.1N 81.7W 80 KT 48HR VT 30/1800Z 21.5N 83.6W 95 KT 72HR VT 31/1800Z 25.0N 87.0W 100 KT 96HR VT 01/1800Z 28.0N 89.5W 100 KT 120HR VT 02/1800Z 30.0N 91.5W 85 KT...INLAND $$ FORECASTER KNABB