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| #64035 (Received by flhurricane at: 4:17 AM 02.Jan.2006) TCDAT5 TROPICAL STORM ZETA DISCUSSION NUMBER 12 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 4 AM EST MON JAN 02 2006 ZETA IS HOLDING ITS OWN IN THE FACE OF MODERATE WESTERLY UPPER-LEVEL SHEAR. A SMALL BURST OF CONVECTION WITH CLOUD TOPS TO -60C HAS REDEVELOPED NEAR AND NORTHEAST OF THE LOW-LEVEL CENTER... AND THE OVERALL CONVECTIVE CLOUD PATTERN HAS CHANGED LITTLE SINCE THE LAST QUIKSCAT AND AMSU INTENSITY ESTIMATES MENTIONED IN THE PREVIOUS DISCUSSION. THEREFORE...THE INITIAL INTENSITY WILL REMAIN AT 45 KT... WHICH IS ALSO SUPPORTED BY A TAFB SHEAR INTENSITY ANALYSIS OF T3.0/45 KT. THE INITIAL MOTION ESTIMATE IS 265/06. NIGHTTIME VISIBLE AND MICROWAVE SATELLITE IMAGERY SUGGEST THAT ZETA MAY HAVE MADE A MORE WESTWARD TURN DURING THE PAST 6 HOURS UNDER THE INFLUENCE OF A STRONG EASTERLY LOW-LEVEL WIND SURGE AS NOTED IN QUIKSCAT AND INFRARED SATELLITE DATA. THE LOW- TO MID-LEVEL RIDGE TO THE NORTH IS EXPECTED TO REMAIN INTACT FOR AT LEAST THE NEXT 72 HOURS... STEERING ZETA WESTWARD OR WEST-SOUTHWESTWARD AS THE CYCLONE WEAKENS AND BECOMES MORE VERTICALLY SHALLOW. THE OFFICIAL FORECAST TRACK IS SIMILAR TO THE PREVIOUS TRACK AND THE GLOBAL MODEL CONSENSUS. UW-CIMSS SHEAR ANALYS1S PRODUCTS INDICATE THE VERTICAL SHEAR MAY RELAX A LITTLE DURING THE NEXT 12 HOURS... WHILE ACCOMPANIED BY A DECREASE IN THE 200 MB TEMPERATURES. THIS WOULD SUGGEST THAT DEEP CONVECTION MAY REMAIN INTACT A LITTLE LONGER THAN THE SHIPS MODEL IS INDICATING. HOWEVER... BY 24-36 HOURS... ALL THE GLOBAL MODELS AGREE THAT THERE WILL BE A SIGNIFICANT INCREASE IN THE STRENGTH OF THE MID- TO UPPER-LEVEL WESTERLY WINDS... WHICH SHOULD ACT TO SHEAR AWAY MOST OF THE ASSOCIATED CONVECTION... AND FINALLY BRING THE 2005 ATLANTIC HURRICANE SEASON TO A MERCIFUL ENDING. EVEN THE LATEST GFDL MODEL RUN HAS BACKED OFF ON MAKING ZETA A HURRICANE. FORECASTER STEWART FORECAST POSITIONS AND MAX WINDS INITIAL 02/0900Z 24.5N 39.7W 45 KT 12HR VT 02/1800Z 24.4N 40.5W 35 KT 24HR VT 03/0600Z 24.3N 41.5W 30 KT 36HR VT 03/1800Z 24.2N 42.8W 25 KT 48HR VT 04/0600Z 24.2N 44.6W 25 KT...REMNANT LOW 72HR VT 05/0600Z...DISSIPATED |
