443  
WTNT45 KNHC 290836  
TCDAT5  
 
POST-TROPICAL CYCLONE TAMMY DISCUSSION NUMBER 40  
NWS NATIONAL HURRICANE CENTER MIAMI FL AL202023  
500 AM AST SUN OCT 29 2023  
 
DURING THE PAST 18 TO 24 HOURS, TAMMY HAS ONLY BEEN MAINTAINING A  
SMALL AND DISORGANIZED PATCH OF DEEP CONVECTION WELL TO THE  
NORTHEAST OF THE FULLY EXPOSED CENTER. ACCORDINGLY, THE DVORAK  
CLASSIFICATIONS HAVE BEEN DECREASING, AND THE LATEST ESTIMATE FROM  
TAFB IS A T1.0/2.0. SATELLITE IMAGES ALSO SHOW THAT THE LOW-LEVEL  
CENTER HAS BECOME ELONGATED AND IS LOSING DEFINITION. BASED ON  
THESE CHARACTERISTICS, TAMMY NO LONGER QUALIFIES AS A TROPICAL  
CYCLONE, AND THIS IS THE LAST ADVISORY ON THIS SYSTEM. THE  
INITIAL INTENSITY IS HELD AT 35 KT.  
 
TAMMY IS MOVING EASTWARD AT 16 KT IN THE MID-LATITUDE WESTERLIES. A  
FAIRLY SHARP TURN TO THE SOUTH IS EXPECTED TO OCCUR TONIGHT FOLLOWED  
BY A MOTION TO THE SOUTHWEST ON MONDAY AND TUESDAY AS THE  
POST-TROPICAL CYCLONE MOVES AROUND THE EAST SIDE OF A BUILDING  
SUBTROPICAL RIDGE. TAMMY IS EXPECTED TO SLOWLY WEAKEN DUE TO  
CONTINUED STRONG VERTICAL WIND SHEAR AND DRY AIR ENTRAINMENT, AND IT  
WILL LIKELY DISSIPATE IN A FEW DAYS.  
 
ADDITIONAL AND FUTURE INFORMATION ON THIS SYSTEM CAN BE FOUND IN  
HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE, UNDER  
AWIPS HEADER NFDHSFAT1, WMO HEADER FZNT01 KWBC, AND ONLINE AT  
OCEAN.WEATHER.GOV/SHTML/NFDHSFAT1.PHP  
 
 
FORECAST POSITIONS AND MAX WINDS  
 
INIT 29/0900Z 32.4N 53.3W 35 KT 40 MPH...POST-TROPICAL  
12H 29/1800Z 31.6N 50.4W 30 KT 35 MPH...POST-TROP/REMNT LOW  
24H 30/0600Z 30.1N 47.6W 30 KT 35 MPH...POST-TROP/REMNT LOW  
36H 30/1800Z 28.5N 46.7W 25 KT 30 MPH...POST-TROP/REMNT LOW  
48H 31/0600Z 27.2N 46.6W 20 KT 25 MPH...POST-TROP/REMNT LOW  
60H 31/1800Z 26.1N 48.0W 20 KT 25 MPH...POST-TROP/REMNT LOW  
72H 01/0600Z...DISSIPATED  
 

 
FORECASTER CANGIALOSI  
 
 
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