Tropical Storm Rafael Forecast Discussion Number 23

By | November 9, 2024

000
WTNT43 KNHC 090234
TCDAT3

Tropical Storm Rafael Discussion Number  23
NWS National Hurricane Center Miami FL       AL182024
900 PM CST Fri Nov 08 2024

Rafael has become significantly less organized since the last 
advisory due to the effects of shear and dry air entrainment. An 
Air Force Reserve Hurricane Hunter aircraft that investigated the 
cyclone a few hours ago reported maximum 700-mb flight-level winds 
of 69 kt in the northwest quadrant and that the central pressure had 
risen to the 985-990 mb range.  The aircraft also reported that the 
eyewall structure had disintegrated and that the 700-mb center was 
located northeast of the surface center.  Microwave satellite 
imagery also suggests that the low-level center is now southwest of 
the main convective mass.  Based on these data and the likely 
continued weakening since the aircraft mission, Rafael is 
downgraded to a tropical storm with the initial intensity of 60 kt. 
This value is a little below the latest CIMSS Satellite Consensus 
estimate.

Even though Rafael remains over the warm waters of the Gulf of 
Mexico, increasing westerly vertical wind shear and intrusions of
dry air should cause steady to rapid weakening for at least the 
next couple of days.  While the shear may decrease some after 48 h, 
the airmass is expected to be too dry for the system to make a 
comeback.  The new intensity guidance follows the trend of the 
global models and the regional hurricane models in showing Rafael 
weakening to a depression by 60 h and degenerating to a remnant 
low pressure area soon after that.

The initial motion is now west-northwest or 285/4 kt.  A low- to 
mid-level ridge to the north of the storm should steer it lowly 
west-northwestward for the next 36 h or so.  After that, the track 
guidance has come into better, although not unanimous, agreement 
that the cyclone will make a small loop or hairpin turn and wind 
up moving south-southwestward as a ridge builds to its west.  The 
new forecast follows the general direction of the somewhat-spread 
consensus models and lies a little to the east of the previous 
forecast after 36 h.

Based on the current track and intensity forecasts, Rafael is 
expected to have little direct impact on land areas. However, 
swells generated by the storm should cause high surf along the 
coast of the Gulf of Mexico.


Key Messages:

1. Swells generated by Rafael are likely to cause life-threatening
surf and rip current conditions along the Gulf Coast for the next
few days.

2. Rafael is forecast to move slowly over the central Gulf of
Mexico this weekend and early next week. Interests in the southern
and southwestern Gulf of Mexico should monitor the progress of this
system.


FORECAST POSITIONS AND MAX WINDS

INIT  09/0300Z 24.8N  89.9W   60 KT  70 MPH
 12H  09/1200Z 25.0N  90.7W   50 KT  60 MPH
 24H  10/0000Z 25.3N  91.5W   40 KT  45 MPH
 36H  10/1200Z 25.6N  91.8W   35 KT  40 MPH
 48H  11/0000Z 25.1N  91.8W   35 KT  40 MPH
 60H  11/1200Z 24.4N  91.9W   30 KT  35 MPH
 72H  12/0000Z 23.4N  92.2W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  13/0000Z 22.0N  92.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  14/0000Z 20.5N  94.0W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Beven

Leave a Reply