Hurricane Imelda Discussion Number  17
NWS National Hurricane Center Miami FL       AL092025
500 PM EDT Tue Sep 30 2025

The hurricane continues to gradually become better organized, with 
curved banding features becoming more prominent over the 
circulation.  Deepest convection is noted over the western 
semicircle of the system with tops to near -70 deg C.  Upper-level 
outflow is fairly well-defined at this time.  The advisory 
intensity is set at 75 kt which is in line with flight-level wind 
observations from the previous Hurricane Hunter mission.  
Subjective and objective Dvorak estimates are a little lower.  
Another Air Force Reserve Unit aircraft is scheduled to investigate 
Imelda soon to check on the intensity and structure of the tropical 
cyclone.

Imelda is moving a little faster toward the east-northeast with a 
motion estimate of 060/10 kt.  A mid-tropospheric trough near the 
U.S. east coast should cause the hurricane to continue to accelerate 
east-northeastward over the next couple of days.  The forecast track 
brings the center of the hurricane near Bermuda in less than 36 
hours, with tropical storm conditions expected to reach Bermuda by 
tomorrow afternoon.   There will likely be some binary interactions 
between Imelda and Humberto since the circulations of the two 
systems are getting very close together.  However, it is difficult 
to specify how significantly this interaction will affect 
Imelda's track. The official forecast is near the southern edge 
of the model guidance suite.  

The hurricane is expected to be within an environment of moderate 
or stronger vertical wind shear, but in a favorable thermodynamic 
environment during the next day or so.  An upper-level trough to 
the northwest of Imelda could contribute to strengthening due to 
baroclinic forcing and upper-level divergence while the system 
nears Bermuda.  This could result in a fairly potent, if not an 
entirely tropical, cyclone passing near the island tomorrow. Later 
in the forecast period, the global models show the system merging 
with a broad baroclinic zone over the north Atlantic, and the 
simulated satellite imagery from these models takes on the 
appearance of an extratropical cyclone in 2-3 days.

KEY MESSAGES:

1. Imelda is expected bring damaging hurricane-force-winds to
Bermuda when it passes near or over that island by Wednesday
afternoon or evening.  A Hurricane Warning is in effect for
Bermuda.

2. Imelda is likely to cause large and damaging waves in Bermuda.

3. Heavy rainfall could cause flash flooding across Bermuda
Wednesday into Thursday.

4. Swells and high surf from both Humberto and Imelda are expected
to produce dangerous marine conditions and rip currents along much
of the East Coast of the United States during the next several days.


FORECAST POSITIONS AND MAX WINDS

INIT  30/2100Z 29.4N  75.5W   75 KT  85 MPH
12H  01/0600Z 30.0N  73.1W   80 KT  90 MPH
24H  01/1800Z 31.2N  68.7W   85 KT 100 MPH
36H  02/0600Z 32.8N  63.4W   85 KT 100 MPH
48H  02/1800Z 34.9N  56.7W   80 KT  90 MPH
60H  03/0600Z 38.0N  51.5W   70 KT  80 MPH...POST-TROP/EXTRATROP
72H  03/1800Z 40.4N  49.1W   60 KT  70 MPH...POST-TROP/EXTRATROP
96H  04/1800Z 45.5N  43.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
120H  05/1800Z 52.5N  32.0W   35 KT  40 MPH...POST-TROP/EXTRATROP

$$
Forecaster Pasch