|
Show Selection: |
| #540154 (Received by flhurricane at: 4:53 PM 04.Sep.2012) TCDAT3 TROPICAL STORM MICHAEL DISCUSSION NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL AL132012 500 PM AST TUE SEP 04 2012 MICHAEL HAS BECOME BETTER ORGANIZED DURING THE DAY. ALTHOUGH GEOSTATIONARY SATELLITE IMAGES INDICATE SOME WARMING OF THE CLOUD TOPS DURING THE PAST HOUR OR SO...RECENT MICROWAVE DATA INDICATE THAT A CURVED BAND NOW WRAPS ABOUT THREE-QUARTERS OF THE WAY AROUND THE CENTER. THE INITIAL WIND SPEED IS SET AT 45 KT...BASED ON DVORAK CLASSIFICATIONS FROM BOTH TAFB AND SAB AND DATA FROM AN EARLIER PARTIAL ASCAT PASS THAT SHOWED A COUPLE OF 35 TO 40 KT WIND VECTORS JUST NORTHWEST OF THE CENTER. ONLY SLIGHT ADDITIONAL STRENGTHENING IS FORECAST IN THE SHORT TERM AS WESTERLY SHEAR IS EXPECTED TO INCREASE OVER THE SMALL CYCLONE DURING THE NEXT DAY OR TWO. AFTER THAT TIME...HOWEVER...AN UPPER-LEVEL LOW IS EXPECTED TO CUT OFF TO THE SOUTHWEST OF MICHAEL. AS THAT OCCURS...A NARROW RIDGE IS EXPECTED TO BUILD OVER THE CYCLONE...RESULTING IN A REDUCTION OF VERTICAL SHEAR. THE OFFICIAL INTENSITY FORECAST IS INCREASED FROM THE PREVIOUS ADVISORY AND LIES FAIRLY CLOSE TO...BUT A LITTLE LOWER THAN...THE SHIPS AND LGEM GUIDANCE. MICHAEL IS MOVING SLOWLY NORTH-NORTHWESTWARD...BUT IS EXPECTED TO TURN TOWARD THE NORTHEAST IN A DAY OR SO AS A MID-LATITUDE TROUGH MOVES EASTWARD ACROSS THE CENTRAL ATLANTIC. AFTER THIS TOUGH BYPASSES MICHAEL...A RIDGE IS FORECAST TO BUILD OVER THE CENTRAL ATLANTIC TO THE NORTH OF THE CYCLONE. AS THE RIDGE SLIDES EASTWARD IN A FEW DAYS...IT SHOULD CAUSE MICHAEL TO TURN NORTHWESTWARD. THE TRACK GUIDANCE IS IN GENERAL AGREEMENT ON THIS SCENARIO AND THE OFFICIAL FORECAST LIES BETWEEN THE MODEL CONSENSUS AND THE PREVIOUS NHC TRACK. FORECAST POSITIONS AND MAX WINDS INIT 04/2100Z 27.5N 43.7W 45 KT 50 MPH 12H 05/0600Z 28.1N 43.9W 50 KT 60 MPH 24H 05/1800Z 28.8N 43.8W 50 KT 60 MPH 36H 06/0600Z 29.4N 43.3W 50 KT 60 MPH 48H 06/1800Z 29.9N 42.9W 50 KT 60 MPH 72H 07/1800Z 30.9N 43.2W 55 KT 65 MPH 96H 08/1800Z 32.0N 44.0W 60 KT 70 MPH 120H 09/1800Z 33.5N 46.0W 60 KT 70 MPH $$ FORECASTER BROWN |
