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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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