Pacific Hurricane Feed

Tropical Storm Frank Forecast Discussion

WTPZ42 KNHC 270837

Tropical Storm Frank Discussion Number   5
NWS National Hurricane Center Miami FL       EP072022
400 AM CDT Wed Jul 27 2022

Frank remains a highly sheared tropical cyclone.  Shortwave
infrared satellite imagery indicates that the center is exposed
well to the northeast of the primary convective mass. This is due
to around 25 kt of northeasterly vertical wind shear as indicated
by the SHIPS guidance.  Recent ASCAT overpasses only caught the far
western portion of the circulation and they were not helpful in
estimating Frank's initial intensity.  Therefore, the initial
wind speed remains at 35 kt, which is in agreement with the latest
subjective and objective Dvorak satellite intensity estimates.

The strong northeasterly shear that is plaguing Frank is not
expected to change much today.  The global model guidance, however
suggests the shear will gradually abate beginning tonight with
upper-level conditions becoming more conducive for strengthening
in 24 to 36 hours.  Given the current structure of the tropical
cyclone, it may take some time for the system to take advantage
of the more favorable environment.  Therefore, the NHC wind speed
forecast only calls for gradual strengthening between 24 and 48
hours, with a slightly faster rate of intensification after that
time.  The NHC forecast is once again on the conservative side and
lies between the SHIPS and lower LGEM model guidance.

Frank is moving westward at about 8 kt. A subtropical ridge to the
north of the cyclone should continue to steer Frank westward to
west-northwestward over the next 48 to 72 hours.  After that time,
a west-northwestward to northwestward motion is forecast as the
cyclone reaches the western periphery of the ridge.  The new NHC
track forecast is once again close to the multi-model consensus aids
and the GFS ensemble mean.


INIT  27/0900Z 12.2N 104.9W   35 KT  40 MPH
 12H  27/1800Z 12.4N 106.4W   35 KT  40 MPH
 24H  28/0600Z 12.7N 108.4W   40 KT  45 MPH
 36H  28/1800Z 13.1N 110.4W   45 KT  50 MPH
 48H  29/0600Z 13.6N 112.3W   50 KT  60 MPH
 60H  29/1800Z 14.4N 114.0W   60 KT  70 MPH
 72H  30/0600Z 15.2N 115.8W   70 KT  80 MPH
 96H  31/0600Z 17.5N 119.1W   75 KT  85 MPH
120H  01/0600Z 19.6N 122.3W   65 KT  75 MPH

Forecaster Brown

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