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Tropical Storm Orlene Discussion Number 9
NWS National Hurricane Center Miami FL EP162022
900 PM MDT Fri Sep 30 2022
Orlene had another burst of deep convection in the past few hours.
Earlier microwave imagery from SSMI/S still showed a small inner
core with a curved band to the south. Subjective and objective
satellite Dvorak classifications continue to range between 45 to 65
kt. Therefore, the initial intensity remains at 55 kt to represent
a blend of these estimates.
The storm is embedded in an environment conducive for further
intensification. Global models suggest the vertical wind shear is
low and the surrounding mid-level humidities are relatively moist
and should remain this way for the next day or so. These
conditions, combined with warm sea surface temperatures, create the
potential for steady to rapid intensification. In fact,
statistical guidance indicates there is a higher than average
probability of rapid intensification in the upcoming 24 hours. The
official forecast still shows Orlene steadily strengthening to peak
near 85 kt in 36 hours and little changes have been made since the
previous advisory. Beyond this period, the vertical wind shear is
expected to increase and induce weakening until landfall. It should
be noted that the NHC intensity forecast is on the high end of the
guidance to account for the possibility of rapid intensification.
The cyclone is moving along the periphery of a ridge over central
Mexico. In the next day, Orlene is expected to turn
north-northeastward in the flow between the ridge and an upper-level
trough over northwestern Mexico and the northern Baja California
peninsula and continue this trajectory until landfall. The latest
NHC track prediction is slightly east of the previous track forecast
and a little faster than the consensus model aids. This forecast
favors the GFS track solution over the ECMWF.
Based on the the forecast track and wind radii, the Government of
Mexico has issued a Tropical Storm Warning and a Hurricane Watch for
portions of mainland Mexico. Additional watches and warnings will
likely be required in the coming day.
Key Messages:
1. Hurricane conditions are possible in the Islas Marias on Sunday,
where a hurricane watch has been issued. Tropical storm conditions
are expected within the tropical storm warning area from Playa
Perula to San Blas within the next 36 h. Tropical storm conditions
are possible over other portions of southwestern and west-central
Mexico in the tropical storm watch area.
2. Heavy rainfall from Orlene is expected to lead to flash flooding,
as well as possible landslides in areas of mountainous terrain of
Southwest Mexico into Monday afternoon.
FORECAST POSITIONS AND MAX WINDS
INIT 01/0300Z 17.0N 107.2W 55 KT 65 MPH
12H 01/1200Z 17.6N 107.2W 65 KT 75 MPH
24H 02/0000Z 18.6N 107.1W 75 KT 85 MPH
36H 02/1200Z 19.8N 106.8W 85 KT 100 MPH
48H 03/0000Z 21.1N 106.5W 75 KT 85 MPH
60H 03/1200Z 22.4N 106.3W 65 KT 75 MPH
72H 04/0000Z 23.6N 106.0W 45 KT 50 MPH...INLAND
96H 05/0000Z 25.5N 105.5W 25 KT 30 MPH...INLAND
120H 06/0000Z...DISSIPATED
$$
Forecaster Bucci
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