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Hurricane Marie Discussion Number   7
NWS National Hurricane Center Miami FL       EP182020
200 PM PDT Wed Sep 30 2020
 
Marie has continued to become better organized today, with a 
well-defined convective band that wraps more than completely around 
the cloud system center.  This yields a Dvorak intensity estimate of 
at least 65 kt, and subjective and objective T-numbers from SAB and 
UW-CIMSS respectively also correspond to an intensity of 65 kt. 
Therefore, the system is being upgraded to a hurricane, which is the 
first for the month of September in this relatively quiet eastern 
North Pacific hurricane season.  The vertical wind shear has 
decreased and is forecast to remain low for the next few days.  
This, combined with a moist low- to mid-tropospheric air mass and 
warm sea surface temperatures, should lead to an environment that is 
very conducive for strengthening.  In fact, the SHIPS RI Index shows 
a significant probability of rapid intensification over the next 24 
hours.  Therefore, the official forecast calls for Marie to become a 
major hurricane tomorrow with additional strengthening during the 
succeeding day.  This is close to the predictions from the two 
corrected consensus techniques, HCCA and FSSE.  By 72 hours, Marie 
should have begun passing over progressively cooler waters, so a 
steady weakening trend is likely to be underway by that time.

The motion continues just north of due west, or 275/14 kt.  The 
track forecast reasoning hasn't changed much from the previous 
advisories.  Over the next few days, the hurricane should be steered 
on a westward to west-northwestward course on the south side of a 
mid-level subtropical ridge.  Right around the end of the forecast 
period, Marie should begin to turn more to the right in response to 
a weakness in the ridge.  The official track forecast is similar to 
the previous one and lies between the simple and corrected dynamical 
consensus predictions.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  30/2100Z 14.3N 115.1W   65 KT  75 MPH
 12H  01/0600Z 14.4N 117.3W   85 KT 100 MPH
 24H  01/1800Z 14.8N 120.0W  100 KT 115 MPH
 36H  02/0600Z 15.6N 122.5W  115 KT 130 MPH
 48H  02/1800Z 16.6N 124.7W  120 KT 140 MPH
 60H  03/0600Z 17.7N 126.7W  120 KT 140 MPH
 72H  03/1800Z 18.6N 128.4W  100 KT 115 MPH
 96H  04/1800Z 20.3N 131.4W   70 KT  80 MPH
120H  05/1800Z 21.8N 134.0W   50 KT  60 MPH
 
$$
Forecaster Pasch
 
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