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Hurricane Olaf Discussion Number  11
NWS National Hurricane Center Miami FL       EP152021
300 AM MDT Fri Sep 10 2021
 
Olaf made landfall very near San Jose del Cabo, Baja California 
Sur, around 0300 UTC based on radar images from Los Cabos and 
surface pressure reports from the region.  Since then, the radar 
data showed that the center crossed the peninsula and re-emerged 
just off the southwestern coast a few hours ago with heavy 
rainbands continuing to stream northward across the area between 
Cabo San Lucas and La Paz.  Assuming some weakening over land, the 
initial intensity is set at 75 kt, which matches the latest Dvorak 
Current Intensity estimates from TAFB and SAB.

The hurricane continues to move toward the northwest but has turned 
more to the left, or 315/11 kt.  A strong mid-level high centered 
over the southern Rockies is forecast to build westward over the 
Pacific during the next few days, which should cause Olaf to turn 
westward by 36 hours and then southwestward by 60 hours until the 
end of the forecast period.  On this track, Olaf will move along 
the southwestern coast of Baja California Sur for the next 12-18 
hours but then turn westward away from land by tonight.  This part 
of the forecast is unchanged from the previous advisory.  There is 
some disagreement among the models on how far south Olaf will move 
on days 3 through 5 (as a remnant low), and the new NHC forecast 
has been nudged southward at those times toward the GFS, ECMWF, and 
HCCA model solutions.

Olaf's proximity to the mountainous terrain of the Baja California 
peninsula during the next 12 to 18 hours will likely cause 
additional steady weakening, and the winds are forecast to fall 
below hurricane force by this evening.  The storm will then move 
over waters colder than 26 degrees Celsius when it turns west of 
Cabo San Lazaro tonight, which should spur additional weakening.  
The SHIPS and LGEM models appear to be keeping Olaf's winds too 
high for the next day or so, and as a result the NHC intensity 
forecast is set below the HCCA consensus aid, closer to the GFS 
and ECMWF intensity trends.  In fact, model-simulated satellite 
imagery suggests that the cold water could cause all of Olaf's deep 
convection to dissipate in 36-48 hours, and the cyclone is therefore 
forecast to degenerate to a post-tropical cyclone by Saturday night.

 
Key Messages:
 
1.  Olaf is forecast to move along the southwestern coast of the 
Baja California peninsula today, with hurricane and tropical storm 
conditions continuing over southern portions of Baja California Sur 
through this evening.  These winds should diminish tonight once 
Olaf weakens and turns westward away from land.

2.  Heavy rains associated with Olaf are expected across portions of
southern Baja California Sur today.  This will pose a threat of 
significant and life-threatening flash flooding and mudslides.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  10/0900Z 23.7N 110.7W   75 KT  85 MPH...NEAR THE COAST
 12H  10/1800Z 24.4N 111.9W   65 KT  75 MPH...NEAR THE COAST
 24H  11/0600Z 24.7N 113.3W   55 KT  65 MPH
 36H  11/1800Z 24.5N 114.5W   45 KT  50 MPH
 48H  12/0600Z 23.9N 115.6W   35 KT  40 MPH...POST-TROPICAL
 60H  12/1800Z 23.0N 116.9W   30 KT  35 MPH...POST-TROP/REMNT LOW
 72H  13/0600Z 22.1N 118.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  14/0600Z 21.0N 120.9W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  15/0600Z 20.5N 122.7W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
$$
Forecaster Berg
 
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