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Hurricane Genevieve Discussion Number 17
NWS National Hurricane Center Miami FL EP122020
900 AM MDT Thu Aug 20 2020
Genevieve's overall satellite appearance continues to slowly
degrade, with a shrinking central dense overcast and dry, stable air
being drawn into the eastern portion of the circulation. The Dvorak
data-T numbers from TAFB, SAB, and the UW-CIMSS ADT have decreased
to 3.5. However, since the CI numbers from these respective analyses
are 4.5, the initial intensity of 65 kt will be based off a blend of
those two values.
Genevieve is forecast to move over gradually cooler waters during
the next 24 h, so a slow weakening trend is expected to continue
through that time. Beyond 24 h, the cyclone will cross the 26C SST
isotherm and reach temperatures below 24C after 48 h. This should
result in a faster rate of weakening, and the cyclone is expected to
degenerate into a remnant low by 60 h. The latest NHC intensity
forecast is essentially an update of the previous one, and is near
the HFIP corrected consensus HCCA.
Genevieve has made its anticipated turn toward the northwest and has
accelerated slightly to 10 kt. This general motion is expected to
continue until the cyclone dissipates later in the forecast
period. On this track, Genevieve will move parallel to the coast of
the southern Baja California peninsula today and then begin to move
away from the peninsula late tonight. The NHC forecast track is
very little changed from the previous one, with the only notable
difference being a slightly faster forward speed. This forecast is
very near the tightly clustered track guidance.
Key Messages:
1. The center of Genevieve is forecast to pass just west of the Baja
California peninsula today. Tropical storm conditions will continue
over southern Baja California Sur through today, and possibly linger
into tonight.
2. Continued heavy rainfall from Genevieve may lead to life-
threatening flash flooding and mudslides across portions of far
southern Baja California Sur through today.
3. Large swells generated by Genevieve will affect portions of
the west-central coast of Mexico and the coast of the southern Baja
California peninsula through Friday.
FORECAST POSITIONS AND MAX WINDS
INIT 20/1500Z 23.3N 111.4W 65 KT 75 MPH
12H 21/0000Z 24.1N 112.5W 60 KT 70 MPH
24H 21/1200Z 25.3N 114.1W 50 KT 60 MPH
36H 22/0000Z 26.6N 115.8W 40 KT 45 MPH
48H 22/1200Z 27.8N 117.8W 30 KT 35 MPH
60H 23/0000Z 28.8N 119.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 23/1200Z 29.7N 121.4W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 24/1200Z 31.1N 122.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 25/1200Z...DISSIPATED
$$
Forecaster Latto
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