####018002471####
WTNT45 KNHC 271443

TCDAT5

 

Tropical Storm Tammy Discussion Number  33

NWS National Hurricane Center Miami FL       AL202023

1100 AM AST Fri Oct 27 2023

 

Tammy appears to have become separate from the frontal zone in 

which it was formerly embedded.  Satellite imagery shows that 

moderately deep convection has developed in a fairly symmetrical 

pattern near the center, and there are also convective bands 

surrounding the center.  This change in structure indicates that 

the system has evolved back into a tropical cyclone, so advisories 

are being re-initiated on Tammy.  Extrapolation of earlier 

scatterometer data suggest that the current intensity is around 55 

kt.



Over the next few days, the atmospheric and oceanic environment 

for Tammy should result in gradual weakening.  The cyclone is 

currently over marginal SSTs, and westerly vertical wind shear is 

likely to increase.  Later in the forecast period, Tammy will 

probably move over slightly warmer waters, but dry air and strong 

shear will likely cause continued weakening.  The official 

intensity forecast is on the high side of the model guidance and 

shows the cyclone weakening to a depression in 5 days, although 

given the environment this may occur sooner.



The storm is drifting slowly northwestward, with a motion near 

320/3 kt.  Tammy should turn eastward in 12 to 24 hours under the 

influence of mid-level westerly flow on the north side of a 

subtropical ridge.  Later in the forecast period, the system is 

expected to turn southeastward and southward on the eastern side of 

a subtropical anticyclone and west of a broad trough over the 

eastern Atlantic.  The official forecast is similar to, but 

somewhat slower than, the model consensus prediction and roughly in 

the middle of the track guidance suite.



Gusty winds are expected in Bermuda through tonight, and a gale 

warning is in effect for that island.





FORECAST POSITIONS AND MAX WINDS

 

INIT  27/1500Z 32.2N  61.1W   55 KT  65 MPH

 12H  28/0000Z 32.4N  61.3W   55 KT  65 MPH

 24H  28/1200Z 32.7N  59.9W   50 KT  60 MPH

 36H  29/0000Z 32.5N  57.5W   45 KT  50 MPH

 48H  29/1200Z 32.0N  54.5W   45 KT  50 MPH

 60H  30/0000Z 30.7N  51.4W   40 KT  45 MPH

 72H  30/1200Z 29.0N  50.0W   40 KT  45 MPH

 96H  31/1200Z 27.5N  50.0W   35 KT  40 MPH

120H  01/1200Z 28.0N  51.0W   30 KT  35 MPH

 

$$

Forecaster Pasch