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#447339 (Received by flhurricane at: 10:46 AM 04.Aug.2011) TCDAT5 TROPICAL STORM EMILY DISCUSSION NUMBER 12 NWS NATIONAL HURRICANE CENTER MIAMI FL AL052011 1100 AM EDT THU AUG 04 2011 SATELLITE IMAGES REVEAL THAT THE CLOUD PATTERN IS A LITTLE BETTER ORGANIZED THAN YESTERDAY WHEN THERE WAS AN EXPOSED LOW LEVEL CENTER. TODAY THE CENTER IS WELL EMBEDDED IN THE CONVECTION WITH CYCLONICALLY CURVED CONVECTIVE BANDS...A POSSIBLE CENTRAL DENSE OVERCAST...AND MORE SIGNIFICANTLY...THE OUTFLOW HAS BECOME ESTABLISHED IN ALL QUADRANTS. HOWEVER...DATA FROM THE RECONNAISSANCE AIRCRAFT EARLIER THIS MORNING SUGGEST THAT THE WINDS REMAIN AT 45 KNOTS AND THE CENTRAL SURFACE PRESSURE IS STEADY. THE INTENSITY FORECAST IS MORE COMPLEX THAN USUAL. THE CYCLONE IS FORECAST TO INTERACT WITH THE HIGH TERRAIN OF HISPANIOLA AND EASTERN CUBA AND THAT IMPLIES WEAKENING. IN ADDITION...GLOBAL MODELS WEAKEN OR DISSIPATE THE CYCLONE...AND OBVIOUSLY THESE MODELS CAN DETECT AN UNFAVORABLE ENVIRONMENT THAT IS NOT APPARENT TO ME. THIS MAKES IT DIFFICULT TO FORECAST INTENSIFICATION WITH SUCH INDICATIONS FROM THE RELIABLE GUIDANCE. ON THE OTHER HAND...SHIPS AND THE GFDL/HWRF MODEL PAIR INTENSIFY THE CYCLONE. GIVEN THIS HIGH DEGREE OF UNCERTAINTY...THE OFFICIAL FORECAST CALLS FOR NO SIGNIFICANT CHANGE IN INTENSITY...OR PERHAPS FOR A SLIGHT WEAKENING AS THE CYCLONE MOVES BY HAITI AND CUBA DURING THE NEXT 24 HOURS. SOME RE-INTENSIFICATION IS POSSIBLE ONCE EMILY REACHES THE AREA OF THE BAHAMAS. SATELLITE AND RECONNAISSANCE PLANE FIXES INDICATE THAT EMILY IS MOVING TOWARD THE WEST-NORTHWEST OR 285 DEGREES AT 4 KNOTS. GLOBAL MODELS CONTINUE TO SHOW A WEAKNESS IN THE SUBTROPICAL RIDGE AND A TROUGH ALONG THE EAST COAST OF THE UNITED STATES. THIS PATTERN FAVORS A TURN TO THE NORTHWEST WITHIN THE NEXT 12 TO 24 HOURS WITH A GRADUAL TURN TO THE NORTH AND NORTHEAST BETWEEN 48 AND 72 HOURS. IT IS UNCERTAIN HOW FAR WEST EMILY WILL REACH BEFORE RECURVATURE... PRIMARILY GIVEN THAT GLOBAL MODELS WEAKEN OR DISSIPATE THE CYCLONE. THE OFFICIAL FORECAST TRACK KEEPS THE CENTER OF EMILY WELL OFF THE EAST COAST OF FLORIDA...AND GIVEN THE SMALL TROPICAL STORM FORCE WIND RADII ON THE WESTERN SIDE OF THE CYCLONE...A TROPICAL STORM WATCH FOR THE FLORIDA SOUTHEAST COAST IS NOT REQUIRED AT THIS TIME. FORECAST POSITIONS AND MAX WINDS INIT 04/1500Z 17.3N 72.3W 45 KT 50 MPH 12H 05/0000Z 18.6N 73.2W 45 KT 50 MPH 24H 05/1200Z 21.0N 75.5W 35 KT 40 MPH 36H 06/0000Z 23.0N 77.0W 45 KT 50 MPH 48H 06/1200Z 25.0N 78.5W 50 KT 60 MPH 72H 07/1200Z 29.0N 77.5W 60 KT 70 MPH 96H 08/1200Z 32.5N 72.0W 65 KT 75 MPH 120H 09/1200Z 36.0N 62.0W 55 KT 65 MPH $$ FORECASTER AVILA |