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Tropical Storm Kevin Discussion Number 4
NWS National Hurricane Center Miami FL EP112021
300 AM MDT Sun Aug 08 2021
Kevin has changed little overnight. Microwave data and infrared
satellite imagery reveal that its convective bands are still
somewhat fragmented with only modest curvature. Recent UW-CIMSS
objective estimates and subjective Dvorak classifications from TAFB
and SAB range from 35 to 45 kt, so the initial intensity is held at
40 kt for this advisory. Unfortunately, no recent scatterometer
passes were available to better assess the cyclone's current
intensity.
The cyclone continues moving westward, or 270 degrees, at around 9
kt. This motion is expected for another 12 to 24 h, before a mid- to
upper-level trough weakens the steering ridge and causes Kevin to
move west-northwestward through midweek. Kevin is forecast to pass
near or just south of Clarion Island on Tuesday. The track guidance
is in good agreement for much of the forecast period, and the latest
official NHC forecast lies near the previous one and generally
follows the multi-model consensus aids.
Kevin appears primed for some strengthening, as the cyclone will
remain in a moist, unstable environment with ample oceanic heat
content for the next couple of days. However, persistent
northeasterly wind shear of 15-20 kt will likely curtail rapid
intensification in an otherwise favorable environment. Despite the
shear, the guidance supports strengthening in the near-term, and the
official NHC forecast shows Kevin becoming a hurricane on Monday.
The cyclone's intensity is forecast to level off by Tuesday, with
weakening thereafter as Kevin moves over cooler waters and continues
to battle moderate shear. The latest NHC intensity forecast is a
little lower than the previous one, but remains near or slightly
above the HFIP corrected consensus approach (HCCA) and IVCN aids.
FORECAST POSITIONS AND MAX WINDS
INIT 08/0900Z 15.8N 108.7W 40 KT 45 MPH
12H 08/1800Z 15.8N 109.6W 50 KT 60 MPH
24H 09/0600Z 16.1N 110.8W 60 KT 70 MPH
36H 09/1800Z 16.7N 112.0W 65 KT 75 MPH
48H 10/0600Z 17.5N 113.3W 70 KT 80 MPH
60H 10/1800Z 18.2N 114.8W 70 KT 80 MPH
72H 11/0600Z 19.1N 116.5W 65 KT 75 MPH
96H 12/0600Z 20.8N 120.0W 55 KT 65 MPH
120H 13/0600Z 22.5N 124.0W 40 KT 45 MPH
$$
Forecaster Reinhart/Pasch
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