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Tropical Storm Orlene Discussion Number 7
NWS National Hurricane Center Miami FL EP162022
900 AM MDT Fri Sep 30 2022
Orlene has not changed much in organization during the past several
hours, with satellite imagery showing a small central dense
overcast with ragged outer convective banding. Interestingly, a
recent SSMI/S overpass indicates that, despite analyses that the
shear is 5 kt or less, the convection under the overcast is a bit
asymmetric and mainly occurring to the southwest and south of the
center. Satellite intensity estimates are essentially unchanged
since the previous advisory, so the initial intensity remains 50 kt.
Orlene is forecast to be in a moist, low-shear environment and over
warm sea surface temperatures for the next 48 h. These conducive
conditions, combined with the small inner core, should allow steady
to rapid strengthening once the core convection becomes more
symmetric. Based on this, the intensity forecast shows the system
reaching a peak intensity of 85 kt in about 48 h. After that time,
the global models are in excellent agreement that the cyclone should
encounter strong southwesterly shear that is likely to cause quick
weakening. The official forecast calls for a 60-kt intensity just
before landfall, and this is near the upper edge of the intensity
guidance. However, there is still a chance that Orlene could be a
hurricane at landfall if the shear is lighter than expected or the
storm moves faster than currently forecast.
The initial motion is still northwestward or 320/4 kt. Rawinsonde
data shows a mid- to upper-level ridge over central Mexico to the
northeast of Orlene, and a combination of rawinsonde data and water
vapor imagery shows a developing mid- to upper-level trough over
northwestern Mexico and the northern Baja California peninsula.
Orlene should turn northward and north-northeastward between these
features during the next couple of days, with this general motion
continuing for the rest of the forecast period. The new forecast
track, which is similar to the previous forecast, calls for the
system to pass west of Cabo Corrientes and near the Islas Marias in
48-60 h and then make landfall on the mainland coast of Mexico just
after 96 h. This forecast is close to the consensus models, but
slower than the GFS model. It should be noted that some of the
ensemble guidance is forecasting the possibility that Orlene will
get so strongly sheared that the northward motion will slow over
the southern Gulf of California and keep the center offshore
through 120 h.
Watches will likely be required for portions of the western coast
of Mexico and the Islas Marias on the next advisory.
FORECAST POSITIONS AND MAX WINDS
INIT 30/1500Z 16.1N 107.1W 50 KT 60 MPH
12H 01/0000Z 16.7N 107.3W 60 KT 70 MPH
24H 01/1200Z 17.5N 107.3W 70 KT 80 MPH
36H 02/0000Z 18.4N 107.2W 80 KT 90 MPH
48H 02/1200Z 19.7N 107.0W 85 KT 100 MPH
60H 03/0000Z 21.4N 106.6W 75 KT 85 MPH
72H 03/1200Z 22.9N 106.4W 60 KT 70 MPH
96H 04/1200Z 25.1N 106.0W 25 KT 30 MPH...INLAND
120H 05/1200Z...DISSIPATED
$$
Forecaster Beven
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