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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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