WTNT44 KNHC 102033 2004254 2033 TCDAT4 HURRICANE IVAN DISCUSSION NUMBER 34 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 PM EDT FRI SEP 10 2004 THERE HAS BEEN NO SIGNIFICANT CHANGES IN THE INTENSITY OR TRACK OF IVAN TODAY. THE HURRICANE HAS A DISTINCT EYE WITHIN A LARGE CENTRAL DENSE OVERCAST AND PLENTY OF BANDING FEATURES. THE OUTFLOW REMAINS WELL ESTABLISHED PRIMARILY TO THE WEST. THE PRESSURE HAS BEEN OSCILLATING DURING THE DAY AND THE LAST READING FROM A RECONNAISSANCE PLANE WAS 937 MB. INITIAL INTENSITY IS ADJUSTED TO 120 KNOTS BASED ON WIND DATA FROM THE RECONNAISSANCE PLANE. SOME FLUCTUATIONS IN INTENSITY ARE LIKELY BEFORE IVAN MOVES NEAR OR OVER JAMAICA WHERE THE EFFECTS OF THE HIGH TERRAIN MAY WEAKEN THE HURRICANE. IT IS POSSIBLE THAT IVAN WILL RE-STRENGTHEN SOME BETWEEN THE CAYMAN ISLANDS AND CUBA WHERE THERE IS A VERY HIGH OCEANIC HEAT CONTENT AND THE SHEAR IS EXPECTED TO REMAIN WEAK. ONCE IN THE GULF OF MEXICO...THE SHEAR IS FORECAST TO INCREASE AND IVAN SHOULD GRADUALLY WEAKEN. HOWEVER...IVAN IS EXPECTED TO REMAIN A DANGEROUS HURRICANE UNTIL IT REACHES THE UNITED STATES. THE HURRICANE IS MOVING TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 11 KNOTS STEERED BY A PERSISTENT SUBTROPICAL RIDGE OVER THE BAHAMAS. AS THE RIDGE WEAKENS...AND A TROUGH DEVELOPS IN THE GULF OF MEXICO...THE HURRICANE WILL LIKELY TURN MORE TO THE NORTHWEST WITH A DECREASE IN FORWARD SPEED. THE FORECAST REMAINS UNCERTAIN AFTER THE HURRICANE CROSSES CUBA. HOWEVER...MODELS ARE BECOMING IN BETTER AGREEMENT ON A TRACK ACROSS THE EASTERN GULF OF MEXICO. ALTHOUGH THE OFFICIAL FORECAST COULD HAVE BEEN SHIFTED A LITTLE WESTWARD DUE TO THE NEW GUIDANCE...IT IS NOT PRUDENT TO MAKE A CHANGE AT THIS TIME. THE OFFICIAL FORECAST IS NOW BASICALLY TO THE RIGHT OF THE GUIDANCE ENVELOPE...AND KEEPS THE HURRICANE ON A NORTHWARD TRACK VERY CLOSE TO THE FLORIDA WEST COAST. FORECASTER AVILA FORECAST POSITIONS AND MAX WINDS INITIAL 10/2100Z 17.0N 76.2W 120 KT 12HR VT 11/0600Z 17.7N 77.5W 115 KT NEAR JAMAICA 24HR VT 11/1800Z 18.8N 78.7W 120 KT 36HR VT 12/0600Z 19.9N 79.8W 125 KT 48HR VT 12/1800Z 21.3N 81.1W 130 KT NEARING CUBA 72HR VT 13/1800Z 24.7N 82.7W 110 KT 96HR VT 14/1800Z 29.0N 83.5W 100 KT 120HR VT 15/1800Z 34.0N 83.5W 30 KT...INLAND $$ wxtlist.k: done