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| #54557 (Received by flhurricane at: 5:03 AM 29.Oct.2005) TCDAT1 HURRICANE BETA DISCUSSION NUMBER 10 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 AM EDT SAT OCT 29 2005 CONVENTIONAL AND MICROWAVE SATELLITE IMAGERY INDICATE BETA HAS BECOME MUCH BETTER ORGANIZED DURING THE PAST 6 HOURS AND HAS STRENGTHENED INTO THE 13TH HURRICANE OF THE 2005 ATLANTIC SEASON. A 29/0211Z SSMI OVERPASS THAT WAS NOT AVAILABLE FOR THE PREVIOUS ADVISORY REVEALED A VERY SMALL EYE EMBEDDED WITHIN THE STRONGEST CONVECTION... WHICH MEANS BETA WAS PROBABLY A HURRICANE AT 00Z. THE CURRENT INTENSITY OF 70 KT IS A BLEND OF DVORAK SATELLITE INTENSITY ESTIMATES OF T4.5/77 KT FROM TAFB AND T4.0/65 KT FROM SAB. THE INITIAL MOTION ESTIMATE IS AN UNCERTAIN 320/03. THE CENTER POSITION HAS BEEN DIFFICULT TO LOCATE UNTIL THE PAST HOUR WHEN AN EYE FEATURE/PRONOUNCED WARM SPOT BECAME APPARENT IN INFRARED IMAGERY NORTH OF PROVIDENCIA ISLAND. THE OVERALL MOTION...HOWEVER ...HAS BEEN VERY SLOW AND BETA MAY EVEN BE STATIONARY. THE COMPACT HURRICANE IS CURRENTLY TRAPPED IN A WEAKNESS IN THE SUBTROPICAL RIDGE THAT LIES ACROSS THE GREATER ANTILLES... WESTERN CARIBBEAN SEA... AND CENTRAL AMERICA. MOST OF THE NHC MODELS CONTINUE TO OVERESTIMATE THE STRENGTH OF THE RIDGE OVER CENTRAL AMERICA AND INSIST ON DRIVING BETA WEST-SOUTHWEST OR SOUTHWESTWARD ACROSS SOUTHERN NICARAGUA AND INTO THE EASTERN PACIFIC. HOWEVER... THEY HAVE BEEN ADVERTISING THIS MOTION FOR NEARLY 3 DAYS NOW AND IT HASN'T HAPPENED YET. THE EXCEPTIONS HAVE BEEN THE UKMET... CANADIAN AND SOME OF THE SIMPLER STATISTICAL MODELS... WHICH HAVE BEEN TAKING BETA ACROSS OR JUST NORTH OF EXTREME NORTHEASTERN NICARAGUA AN INTO THE YUCATAN PENINSULA OR THE YUCATAN CHANNEL. THOSE MODELS HAVE HAD A NORTHWARD BIAS AND ALSO A FAST SPEED BIAS. THE SHORTWAVE TROUGH CURRENTLY OVER THE EASTERN GULF OF MEXICO THAT IS INDUCING THE WEAKNESS IN THE SUBTROPICAL RIDGE SHOULD CONTINUE TO MOVE EASTWARD ACROSS FLORIDA AND INTO THE ATLANTIC DURING THE NEXT 24 HOURS. THIS SHOULD ALLOW THE RIDGE TO THE NORTH OF BETA TO GRADUALLY BUILD WESTWARD AND SLOWLY NUDGE THE HURRICANE INTO NICARAGUA. THE OFFICIAL FORECAST TRACK IS CLOSE TO THE PREVIOUS TRACK AND LIES BETWEEN THE TWO EXTREMES IN THE MODEL GUIDANCE MENTIONED EARLIER. THE UPPER-LEVEL OUTFLOW PATTERN REMAINS WELL ESTABLISHED AND THE VERTICAL SHEAR IS FORECAST TO WEAKEN BELOW 10 KT BY 24 HOURS. THE VERY WARM SSTS AND THE UNUSUALLY MOIST MID-LEVELS OF THE ATMOSPHERE ARE CONDUCIVE TO BETA RAPIDLY INTENSIFYING... IF COLD UPWELLING DOES NOT OCCUR BENEATH THE SLOW MOVING CYCLONE. IT IS POSSIBLE THAT BETA COULD BECOME A STRONG CATEGORY 2 OR EVEN A CATEGORY 3 HURRICANE BEFORE IT MAKES LANDFALL ALONG THE COAST OF NICARAGUA. REGARDLESS OF THE INTENSITY OF BETA AT LANDFALL...THIS TROPICAL CYCLONE WILL BRING TORRENTIAL RAINFALL TO PORTIONS OF CENTRAL AMERICA...PRIMARILY NICARAGUA... CAUSING CONSIDERABLE DAMAGE... AND LIFE-THREATENING FLASH FLOODS AND MUD SLIDES. IN ADDITION... SOME OF THE DEEP TROPICAL MOISTURE ASSOCIATED WITH BETA MAY GET DRAWN INTO A DEVELOPING WINTER-TYPE LOW PRESSURE SYSTEM OVER THE GULF OF MEXICO... RESULTING IN STRONG THUNDERSTORMS AND HEAVY RAINFALL ACROSS CUBA... FLORIDA... AND PORTIONS OF THE SOUTHEASTERN U.S. BY THE MIDDLE OF NEXT WEEK. FORECASTER STEWART FORECAST POSITIONS AND MAX WINDS INITIAL 29/0900Z 13.7N 81.5W 70 KT 12HR VT 29/1800Z 14.1N 82.1W 80 KT 24HR VT 30/0600Z 14.3N 83.0W 90 KT 36HR VT 30/1800Z 14.4N 83.9W 50 KT...INLAND NERN NICARAGUA 48HR VT 31/0600Z 14.4N 84.9W 25 KT...DISSIPATING INLAND 72HR VT 01/0600Z 14.4N 86.9W 20 KT...REMNANT LOW INLAND 96HR VT 02/0600Z 14.5N 88.8W 20 KT...REMNANT LOW INLAND 120HR VT 03/0600Z...DISSIPATED INLAND |
