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| #58275 (Received by flhurricane at: 9:34 AM 24.Nov.2005) TCDAT3 TROPICAL STORM DELTA DISCUSSION NUMBER 4 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 10 AM EST THU NOV 24 2005 CONVENTIONAL AND MICROWAVE SATELLITE IMAGERY INDICATE DELTA HAS CONTINUED TO STRENGTHEN. AN EYE FEATURE HAS BECOME BETTER DEFINED DURING THE PAST FEW HOURS AND A 24/0826Z QUIKSCAT OVERPASS INDICATED SEVERAL 60-KT WIND VECTORS TO THE NORTH AND SOUTH OF THE CENTER. THESE WINDS WERE IN AREAS OF NO OR WEAK RAIN REGIONS... SO THEY ARE CONSIDERED TO BE VALID... ESPECIALLY SINCE THOSE VECTORS AND THE ENTIRE EYE WERE SURROUNDED BY A LARGER AREA 50-55 KT WIND VECTORS. DELTA IS CLOSE TO BECOMING A HURRICANE... AND THE ONLY REASON THE INTENSITY WAS HELD DOWN WAS DUE TO THE LACK OF ANY CONVECTION IMMEDIATELY SURROUNDING AROUND THE EYE FEATURE. THE INITIAL MOTION ESTIMATE 090/02 KT. WATER VAPOR IMAGERY AND RECENT SATELLITE POSITION ESTIMATES SUGGEST THAT DELTA MAY HAVE BOTTOMED OUT AT THE BASE OF THE LARGE TROUGH/CYCLONIC GYRE IN WHICH THE CYCLONE IS EMBEDDED. THE MAJORITY OF THE NHC MODEL GUIDANCE CONTINUES TO TAKE DELTA SLOWLY SOUTHWEST AND THEN WESTWARD BEFORE TURNING IT BACK TO THE NORTH... DESPITE THE BROAD COUNTER-CLOCKWISE MOTION THE CYCLONE HAS MAINTAINED FOR THE PAST 48 HOURS. WHILE IT IS POSSIBLE THAT DELTA COULD MAKE SOME SMALL LOOPS OR WOBBLES TO THE SOUTH OR SOUTHWEST... THE OFFICIAL FORECAST CALLS FOR LITTLE MOTION FOR THE NEXT 24 HOURS. THE CYCLONE IS EXPECTED TO TURN BACK TO THE NORTH BY 36 HOURS. THE OFFICIAL TRACK IS A LITTLE TO THE EAST OF THE PREVIOUS ADVISORY FOR THE FIRST 36 HOURS TO ACCOUNT FOR THE MORE EASTWARD INITIAL POSITION... BUT THEN COMES BACK ON TRACK BY 72-120 HOURS. A NORTHWESTWARD TURN BY 120H IS EXPECTED DUE TO SOME BINARY INTERACTION WITH AN EXTRATROPICAL LOW PRESSURE SYSTEM THAT IS FORECAST TO DEVELOP TO THE WEST OF DELTA. DELTA IS CURRENTLY LOCATED BENEATH AN UPPER-LEVEL SHEAR AXIS ALONG 38-39N LATITUDE. THIS HAS ALLOWED FOR THE VERTICAL SHEAR TO DECREASE AND FOR ANTICYCLONIC OUTFLOW TO DEVELOP. THE 300 MB WINDS ARE DEPICTED BY ALL THE GLOBAL MODELS AS BEING AT LEAST 20 KT LESS THAN THEY ARE 200 MB... SO THE SHIPS MODEL VERTICAL SHEAR ANALYSIS OF 42 KT APPEARS TO BE TOO STRONG. THE MODELS MAINTAIN RELATIVELY WEAK 300 MB WINDS OVER DELTA FOR THE NEXT 24-36 HOURS... SO THERE IS SOME OPPORTUNITY FOR THE CYCLONE TO REACH HURRICANE STATUS BEFORE STRONGER UPPER-LEVEL WESTERLY SHEAR KICKS IN BY 48 HOURS. FORECASTER STEWART FORECAST POSITIONS AND MAX WINDS INITIAL 24/1500Z 24.8N 38.8W 60 KT 12HR VT 25/0000Z 24.8N 38.6W 65 KT 24HR VT 25/1200Z 25.3N 38.5W 60 KT 36HR VT 26/0000Z 25.9N 38.6W 60 KT 48HR VT 26/1200Z 26.6N 38.7W 55 KT 72HR VT 27/1200Z 29.0N 39.0W 55 KT 96HR VT 28/1200Z 32.0N 40.0W 50 KT...BECOMING EXTRATROPICAL 120HR VT 29/1200Z 34.0N 41.5W 50 KT...EXTRATROPICAL |
