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Tropical Storm Dolores Discussion Number 4
NWS National Hurricane Center Miami FL EP042021
1000 PM CDT Fri Jun 18 2021
Deep convection has been trying to consolidate closer to the
estimated center of Dolores over the past several hours, suggesting
that the broad circulation of the cyclone may be starting to
contract. The CIMSS ADT and SATCON indicated some strengthening
since the previous advisory, which justified increasing the storm's
intensity to 45 kt for the 0000 UTC intermediate advisory. The
recent Dvorak intensity estimates from both TAFB and SAB are in
agreement with this value, and therefore 45 kt will be this
advisory's initial intensity.
Dolores is moving to the northwest at 8 kt around the periphery of a
mid-level ridge to its east. A turn to the north-northwest along
with a slight increase in forward speed is expected to occur through
Sunday morning. There is about 120 n mi of spread in the track
guidance at 24 h, and with the cyclone's angle of approach to the
coast of Mexico, a variation in the track produces a large
difference in the coastlines potentially affected by Dolores. The
westernmost guidance has the center of the cyclone clipping the
coast just north of Manzanillo in about 24 h, while the easternmost
solutions make landfall in about 18 h near Punta San Telmo. Overall,
the guidance has shifted little this evening, and therefore the
latest NHC track forecast is very near the previous one, which lies
near the various multi-model track consensus. This track would take
the center of Dolores across the coast between Punta San Telmo and
Manzanillo early Saturday afternoon.
The surrounding environmental conditions are favorable for Dolores
to continue to strengthen, with the main inhibiting factor being the
broad circulation as indicated by an ASCAT overpass earlier this
afternoon. Dolores is currently forecast to peak at an intensity of
55 kt by late Saturday morning before making landfall. How much the
circulation consolidates over the next 12-18 h will likely determine
if the peak intensity of Dolores prior to landfall is higher or
lower than indicated. After landfall, Dolores should rapidly weaken
over the rugged terrain of western Mexico, with the guidance in good
agreement on dissipating the cyclone by Sunday morning. Other than
indicating an earlier dissipation, the new NHC intensity forecast
has changed little from the previous one.
Key Messages:
1. Dolores is expected to continue strengthening tonight and early
on Saturday, and it could be near hurricane strength when it reaches
the coast of west-central Mexico by Saturday afternoon. A tropical
storm warning and a hurricane watch are in effect for portions of
the southwestern and west-central coasts of Mexico.
2. Heavy rains are forecast over coastal sections of the Mexican
states of Oaxaca, Guerrero, Michoacan, Colima, Jalisco, and Nayarit
during the next few days, which could result in life-threatening
flash flooding and mudslides.
FORECAST POSITIONS AND MAX WINDS
INIT 19/0300Z 16.3N 102.8W 45 KT 50 MPH
12H 19/1200Z 17.6N 103.6W 55 KT 65 MPH
24H 20/0000Z 20.0N 104.3W 35 KT 40 MPH...INLAND
36H 20/1200Z 22.6N 104.9W 25 KT 30 MPH...POST-TROP/INLAND
48H 21/0000Z...DISSIPATED
$$
Forecaster Latto
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