Tropical Storm JIMENA
ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM TROPICAL STORM JIMENA DISCUSSION NUMBER 3 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2 PM PDT THU AUG 28 2003 THE CONVECTIVE PATTERN OF TROPICAL DEPRESSION TEN-E HAS BECOME BETTER ORGANIZED TODAY...WITH THE FORMATION OF A RAGGED CDO AND OCCASIONAL GLIMPSES OF EYE-LIKE HOLES IN VISIBLE AND AMSU IMAGERY. HOWEVER...LOW CLOUD MOTIONS AND A QUIKSCAT OVERPASS INDICATE THAT THE LOW-LEVEL CIRCULATION REMAINS ELONGATED EAST-WEST...AND THE SYSTEM MAY NOT BE AS STRONG AS IT LOOKS. SATELLITE INTENSITY ESTIMATES ARE 35 KT FROM AFWA AND 45 KT FROM TAFB AND SAB. BASED ON ALL THE ABOVE...THE DEPRESSION IS UPGRADED TO TROPICAL STORM JIMENA WITH 35 KT WINDS. SATELLITE IMAGERY SUGGEST THE CENTER IS A LITTLE SOUTH OF THE PREVIOUS POSITION. THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 285/12...AND IT MAY BE EVEN MORE WESTWARD. JIMENA IS ON THE SOUTH SIDE OF A LARGE SUBTROPICAL RIDGE...WHICH SHOULD PERSIST THROUGH THE FORECAST PERIOD. THE STORM SHOULD THUS MOVE WESTWARD TO WEST-NORTHWESTWARD...WITH THE BIGGEST QUESTION BEING HOW FAR NORTH. THE LARGE-SCALE MODELS AND THE GFDL ARE TIGHTLY CLUSTERED AROUND A WESTWARD TRACK BETWEEN 14N-16.5N...WHILE THE BAM MODELS...CLIPER... AND NHC 91 FORECAST A WEST-NORTHWESTWARD TRACK. THE OFFICIAL FORECAST IS BETWEEN THESE TWO CAMPS...AND IS A LITTLE SOUTH AND FASTER THAN THE PREVIOUS TRACK. IF THE MORE WESTWARD MOTION IS CORRECT...THE FORECAST TRACK MAY HAVE TO BE ADJUSTED SOUTHWEST IN SUBSEQUENT ADVISORIES. JIMENA IS CURRENTLY OVER 28C...AND SHOULD STAY OVER THIS TEMPERATURE FOR 12-24 HR. AFTER ABOUT 48 HR...THE CYCLONE SHOULD BE OVER 26C WATER. UPPER-LEVEL WINDS ARE FORECAST TO REMAIN FAVORBALE BY THE LARGE-SCALE MODELS...SO THE SSTS SHOULD CONTROL THE INTENSITY. THE INTENSITY FORECAST CALLS FOR GRADUAL STRENGTHENING TO MINIMAL HURRICANE STRENGTH...FOLLOWED BY LITTLE CHANGE AS THE CYCLONE REACHES THE MARGINAL SSTS. A TRACK NORTH OF THE CURRENT FORECAST TRACK WOULD LIKELY PRODUCE A WEAKER CYCLONE...WHILE A TRACK SOUTH OF THE CURRENT FORECAST COULD ALLOW JIMENA TO STRENGTHEN FURTHER. FORECASTER BEVEN FORECAST POSITIONS AND MAX WINDS INITIAL 28/2100Z 14.6N 132.4W 35 KT 12HR VT 29/0600Z 15.1N 134.2W 40 KT 24HR VT 29/1800Z 15.7N 136.4W 45 KT 36HR VT 30/0600Z 16.2N 138.6W 55 KT 48HR VT 30/1800Z 16.7N 141.0W 65 KT 72HR VT 31/1800Z 17.5N 146.5W 65 KT 96HR VT 01/1800Z 17.5N 152.0W 65 KT 120HR VT 02/1800Z 17.5N 158.0W 65 KT NNNN