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Tropical Storm Olaf Discussion Number   6
NWS National Hurricane Center Miami FL       EP152021
900 PM MDT Wed Sep 08 2021
 
Olaf appears to be gradually strengthening.  Deep convection has
been increasing over the center, and banding features are becoming a
little more pronounced.  The latest Dvorak estimates range from 35
to 45 kt. Since the system appears to be better organized from
the time of the ASCAT pass earlier today, the initial intensity is
nudged up and set near the high end of the estimates at 45 kt.
 
Satellite images and recent microwave data suggest that the center
of Olaf is a little to the east of the previous track, and the
latest initial motion estimate is 335/6 kt.  Olaf is expected to
move generally northwestward for another 24 to 36 hours, which
should bring the system just off the coast of southern Baja
California Sur during that time.  There is some spread in the models
on how close the storm will get to the coastline, with the GFS to
the east of the official forecast and the UKMET and ECMWF to the
west and farther offshore.  Beyond 36 hours, Olaf is expected to be
located to the south of a strong mid-level ridge and that will cause
a turn to the west-northwest away from Mexico.  The NHC track
forecast is adjusted again to the east of the previous one in the
short term and then to the south of the previous one at the longer
lead times. The new track forecast lies near the middle of the
guidance envelope, near the various consensus aids.
 
Olaf is located over warm waters, and embedded in a low wind shear
and fairly moist environment.  These conditions should allow for
additional strengthening during the next day or so.  Although not
explicitly forecast, Olaf could become a hurricane when it is just
off the coast of southern Baja California Sur, and a hurricane
watch remains in effect for the possibility of those winds
occurring on land.  By Friday, a combination of cooler waters and a
much drier environment should cause steady weakening, and the
system is likely to become a remnant low over the weekend.  The NHC
intensity forecast lies close to the IVCN and IVDR consensus models.
 
 
Key Messages:
 
1.  Olaf is forecast to strengthen to near hurricane intensity while
it passes offshore of the southern portion of Baja California Sur
Thursday and Friday. Tropical storm conditions are expected and
hurricane conditions are possible across that area beginning late
Thursday. Interests there should continue to monitor the progress of
Olaf.
 
2.  Heavy rains associated with Tropical Storm Olaf are possible
across portions of far southern Baja California Sur Thursday through
Friday.  This will pose a threat of flash flooding and mudslides.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  09/0300Z 20.0N 108.0W   45 KT  50 MPH
 12H  09/1200Z 20.8N 108.7W   55 KT  65 MPH
 24H  10/0000Z 21.9N 109.9W   60 KT  70 MPH
 36H  10/1200Z 22.8N 111.4W   60 KT  70 MPH
 48H  11/0000Z 23.4N 113.0W   55 KT  65 MPH
 60H  11/1200Z 23.5N 114.4W   45 KT  50 MPH
 72H  12/0000Z 23.3N 115.7W   35 KT  40 MPH
 96H  13/0000Z 22.6N 118.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  14/0000Z 21.7N 121.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 
$$
Forecaster Cangialosi
 
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