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Tropical Storm ISELLE


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Tropical Storm Iselle Discussion Number   2
NWS National Hurricane Center Miami FL       EP142020
200 PM PDT Wed Aug 26 2020
 
A recent ASCAT overpass revealed that the cyclone barely has a
closed center, and is embedded in a northeast-southwest oriented
monsoon gyre feature. However, this same overpass sampled a 
decent sized area of 33-34 kt winds over the southeastern quadrant, 
and therefore the system has been upgraded to 35 kt Tropical Storm 
Iselle. 

Assuming that the storm does not get absorbed into the monsoon gyre 
and open back into a trough, it should maintain its intensity over 
warm waters, while battling 20-30 kt of easterly to northeasterly 
shear over the next few days. After that time, the shear persists 
but Iselle should begin to move over waters with a lower oceanic 
heat content. This should cause the cyclone to weaken and eventually 
degenerate into a remnant low late in the forecast period. The 
latest NHC intensity forecast is near the various intensity 
consensus guidance.
 
The depression is moving northeast at 4 kt. This motion is expected 
to continue for the next day or so as it moves around the cyclonic 
gyre stretching southwestward from Hurricane Laura over central 
Mexico and into the eastern Pacific. Afterward, a gradual turn 
toward the north-northwest and west-northwest is expected as high 
pressure currently over the southwestern U.S. builds westward over 
the Baja California peninsula and adjacent eastern Pacific. The NHC 
forecast track is little changed from the previous one, and lies 
near the HFIP corrected consensus, or HCCA. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  26/2100Z 15.5N 116.8W   35 KT  40 MPH
 12H  27/0600Z 16.0N 116.3W   35 KT  40 MPH
 24H  27/1800Z 16.8N 115.7W   35 KT  40 MPH
 36H  28/0600Z 17.3N 115.1W   35 KT  40 MPH
 48H  28/1800Z 17.9N 114.4W   35 KT  40 MPH
 60H  29/0600Z 18.7N 113.7W   35 KT  40 MPH
 72H  29/1800Z 19.9N 113.7W   30 KT  35 MPH
 96H  30/1800Z 21.4N 114.9W   30 KT  35 MPH...POST-TROP/REMNT LOW
120H  31/1800Z 22.1N 116.1W   25 KT  30 MPH...POST-TROP/REMNT LOW
 
$$
Forecaster Latto
 
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