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Hurricane Linda Discussion Number 29
NWS National Hurricane Center Miami FL EP122021
1100 PM HST Mon Aug 16 2021
Linda has weakened, tonight. The eyewall has warmed during the past
6 hours, particularly in the west semicircle, and the convective
ring has also decreased significantly in coverage, but still
completely surrounds the 38 n mi diameter eye. The various
subjective and objective satellite intensity estimates have all
decreased, and a blend of these data yields an initial intensity of
80 kt for this advisory. It's worth noting that Linda appears to be
losing its annular cloud pattern which now consists of spiral
banding features showing up in all quadrants.
As research has proven in the past, tropical cyclones that are
characterized by an annular cloud pattern usually weaken more slowly
than at a climatological rate in the eastern Pacific. Despite
currently moving over sub-26C waters, the low shear surrounding
environment could still offset the negative contribution of
gradually decreasing sea surface temperatures, at least for the next
12 hours. As I mentioned in the previous discussion, Linda may
still have an outside chance of restrengthening some, or leveling
off again, while the cyclone moves back over marginally warmer
water. Beyond this short term period, Linda is forecast to move
over much colder waters which should induce a faster weakening as
the cyclone crosses into the central Pacific. Global models
generally agree that Linda will lose organized deep convection in 4
days and become a post-tropical gale, and this is indicated in the
official forecast.
The initial motion estimate is 265/9 kt. There is no significant
change to the previous forecast track or reasoning. Linda should
continue moving westward for the next 12 hours or so, followed by a
west-northwestward motion while the hurricane moves around the
southwest periphery of a mid-tropospheric high located over the
northeastern Pacific. The new NHC forecast track is essentially
just an extension of the previous one and is based primarily on the
better performing TVCN and HCCA consensus guidance.
A 0614 UTC METOP-B scatterometer pass indicated that Linda's wind
radii had contracted in all quadrants, and adjustments were made,
accordingly.
FORECAST POSITIONS AND MAX WINDS
INIT 17/0900Z 17.6N 126.4W 80 KT 90 MPH
12H 17/1800Z 17.7N 127.8W 80 KT 90 MPH
24H 18/0600Z 18.1N 129.8W 75 KT 85 MPH
36H 18/1800Z 18.8N 132.2W 70 KT 80 MPH
48H 19/0600Z 19.8N 134.9W 65 KT 75 MPH
60H 19/1800Z 20.7N 137.7W 60 KT 70 MPH
72H 20/0600Z 21.3N 140.5W 50 KT 60 MPH
96H 21/0600Z 22.1N 145.8W 40 KT 45 MPH...POST-TROPICAL
120H 22/0600Z 22.7N 149.9W 35 KT 40 MPH...POST-TROPICAL
$$
Forecaster Roberts
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