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Tropical Storm Iselle Discussion Number  15
NWS National Hurricane Center Miami FL       EP142020
900 PM MDT Sat Aug 29 2020
 
Most of the deep convection associated with Iselle has been 
displaced to the west of the center due to strong easterly shear 
caused by a large upper-level anticyclone to the northeast.  Based 
on the decreased organization, it is assumed that the cyclone has 
been gradually spinning down this evening, and the current 
intensity estimate is set at 35 kt.  Although the shear may relax a 
bit in a day or so, Iselle will be moving over increasingly cooler 
waters during that time.  Therefore, continued weakening is 
anticipated, and the system will likely degenerate into a remnant 
low in 12 to 24 hours.  The official intensity forecast is at the 
high end of the model guidance.

The cyclone has been moving north-northeastward, at around 020/8 
kt, on the west side of a mid-level high pressure area.  The 
weakening and increasingly shallow system should gradually turn to 
the left under the influence of the lower-level flow.  The official 
track forecast is about in the middle of the guidance envelope.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  30/0300Z 21.8N 114.2W   35 KT  40 MPH
 12H  30/1200Z 22.9N 114.3W   30 KT  35 MPH
 24H  31/0000Z 23.9N 114.6W   30 KT  35 MPH...POST-TROP/REMNT LOW
 36H  31/1200Z 24.5N 114.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  01/0000Z 25.0N 115.3W   20 KT  25 MPH...POST-TROP/REMNT LOW
 60H  01/1200Z 25.5N 115.7W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  02/0000Z...DISSIPATED
 
$$
Forecaster Pasch
 
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