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Tropical Storm Elida Discussion Number   7
NWS National Hurricane Center Miami FL       EP092020
900 AM MDT Mon Aug 10 2020
 
Elida is very close to reaching hurricane strength.  A 1218 UTC 
SSMIS microwave pass revealed a nearly enclosed eyewall that was 
somewhat eroded on the west side, possibly due to a bit of 
north-northwesterly shear (as shown by the SHIPS diagnostics).  
Subjective Dvorak estimates from TAFB and SAB are T3.5/55 kt, while 
the objective guidance from UW-CIMSS is about 5-10 kt higher.  
Because of the gradually improving structure in microwave imagery, 
the initial intensity is set at 60 kt, which is a blend of the 
intensity estimates.

Located along the southern periphery of a mid-level ridge which 
extends from the south-central U.S. southwestward into the Pacific, 
Elida is moving west-northwestward at 300/13 kt.  Confidence in the 
track forecast remains high since this ridge will be the main 
driving force for the next 2-3 days, keeping Elida on a 
west-northwestward but gradually slowing trajectory.  In about 3 
days, a weaker Elida will turn westward and slow down even further 
due to lighter low-level steering winds.  The spread in the guidance 
does increase beyond 60 hours, particularly with the GFS showing a 
significant poleward motion, but this unlikely scenario appears to 
be due to the model tracker deviating from the path of the surface 
circulation.  The new NHC track forecast is nudged only slightly 
north of the previous forecast, mainly due to a continuation of 
Elida's recent trajectory.  This new forecast is a blend of the 
previous forecast and the NOAA-HCCA and TVDG consensus approaches.

The SHIPS model suggests that whatever shear is still affecting 
Elida should die down within the next 12 hours, and the storm has 
about 24 hours left over waters warmer than 26 degrees Celsius.  
These conditions should allow for continued strengthening over the 
next day or so, with rapid intensification still a possibility.  
For that reason, the NHC intensity forecast is just above nearly 
all of the guidance at 24 hours.  After 24 hours, gradual weakening 
should commence as Elida moves over cooler waters, and the rate of 
weakening is likely to accelerate by day 3 once southwesterly shear 
increases.  Elida is expected to become a remnant low by day 4 and 
dissipate by day 5, in accordance with the solutions shown by the 
global models.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  10/1500Z 18.9N 109.8W   60 KT  70 MPH
 12H  11/0000Z 19.7N 111.9W   70 KT  80 MPH
 24H  11/1200Z 20.5N 114.5W   80 KT  90 MPH
 36H  12/0000Z 21.3N 117.0W   75 KT  85 MPH
 48H  12/1200Z 22.0N 119.3W   65 KT  75 MPH
 60H  13/0000Z 22.5N 121.3W   50 KT  60 MPH
 72H  13/1200Z 22.7N 122.8W   40 KT  45 MPH
 96H  14/1200Z 22.5N 125.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  15/1200Z...DISSIPATED
 
$$
Forecaster Berg
 
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