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Hurricane Genevieve Discussion Number  11
NWS National Hurricane Center Miami FL       EP122020
900 PM MDT Tue Aug 18 2020
While Genevieve continues to have a distinct eye on satellite 
images, the inner-core convection has weakened during the past 
several hours, although there is little evidence of any eyewall 
replacement cycle starting. The majority of the satellite estimates 
range from 100 to 110 kt, and a blend of these values gives an 
initial wind speed of 105 kt.

My strong suspicion is that the hurricane has weakened today due to 
it encountering cooler SSTs from the wake of Hurricane Elida (from 
last week), and these waters will likely help limit any near-term 
chance of strengthening.  While Genevieve should move north of the 
wake tomorrow, its slow movement and fairly large size could help 
to maintain upwelling and cooler waters near the core. In a couple 
of days, quickly falling SSTs should cause rapid weakening, and 
Genevieve is forecast to be a non-convective low in 4 days over 
waters near 23C. The new forecast is lower than the previous one, 
but it is still above the model consensus at most times before 48 
The hurricane has turned to the right tonight, with the latest 
initial motion estimated to be 325/9 kt.  A slightly slower 
northwestward to north-northwestward motion is expected during the 
next day or so due to steering from a distant ridge over central 
Mexico, taking the core of the hurricane near but just west of the 
southern Baja California peninsula during that time.  Similar to the 
previous cycle, the models have shifted closer to the Baja 
California Sur coast but still about 60 n mi offshore, and the NHC 
forecast is adjusted in that direction. Thereafter, a mid-level 
ridge over the southwestern United States should cause Genevieve to 
turn more toward the west-northwest or northwest, away from the Baja 
coast. A small eastward trend is noted at long range as well, and 
the official forecast follows that lead. 
Key Messages:
1. The center of Genevieve is forecast to move just west of the Baja
California peninsula, but it is still expected to cause tropical
storm conditions across portions of southern Baja California Sur.
These conditions are expected to begin Wednesday afternoon and
could spread northwestward through Thursday.
2. Large swells generated by Genevieve are affecting portions of the
coast of southern Mexico and will spread northward along the coast
of Mexico to the Baja California peninsula through Thursday.
INIT  19/0300Z 19.5N 109.0W  105 KT 120 MPH
 12H  19/1200Z 20.5N 109.7W  105 KT 120 MPH
 24H  20/0000Z 21.5N 110.4W  100 KT 115 MPH
 36H  20/1200Z 22.4N 111.3W   90 KT 105 MPH
 48H  21/0000Z 23.1N 112.3W   75 KT  85 MPH
 60H  21/1200Z 24.0N 113.6W   65 KT  75 MPH
 72H  22/0000Z 25.1N 115.2W   55 KT  65 MPH
 96H  23/0000Z 27.5N 118.7W   40 KT  45 MPH...POST-TROPICAL
120H  24/0000Z 29.5N 121.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
Forecaster Blake