Pacific Hurricane and Tropical Cyclone Track Updates

Tropical Storm Estelle Forecast Discussion

WTPZ41 KNHC 160235

Tropical Storm Estelle Discussion Number   3
NWS National Hurricane Center Miami FL       EP062022
1000 PM CDT Fri Jul 15 2022

A series of microwave images since the last advisory show that the 
depression's low-level structure has become better defined, with 
the center nearly surrounded by a cyan ring in the 37-GHz channel.  
In addition, a tight band of deep convection with cloud tops colder 
than -80 degrees Celsius has been persisting near the center.  
Dvorak estimates from TAFB and SAB are a consensus T2.5, so the 
depression is upgraded to Tropical Storm Estelle with 35-kt winds.  
However, this could be a conservative estimate given the improved 
structure, and objective intensity estimates are running slightly 

The initial motion is a little faster toward the northwest, or 
310/9 kt, but satellite location fixes suggest the storm is 
beginning to turn toward the west-northwest as expected.  Mid-level 
ridging is forecast to be entrenched over the southwestern United 
States for the next 5 days, which should steer Estelle on a general 
west-northwestward heading for the entirety of the forecast period. 
There is not much spread among the track guidance, at least 
cross-track wise, but it is notable that the GFS solution is a bit 
slower than the other reliable guidance.  The NHC track forecast is 
just a little slower than the consensus aids to account for that 
slower scenario, and this update is not too different from the 
previous forecast.

Despite Estelle's improved structure, a sharp edge on the eastern 
side of the deep convection in infrared imagery suggests there is 
still some shear affecting the cyclone, and SHIPS is showing 10-15 
kt of deep-layer shear out of the northeast.  The GFS and ECMWF 
versions of SHIPS differ a bit on when that shear will decrease, 
although both versions show Estelle benefiting from high values of 
upper-level divergence for the next 24-48 hours.  Combined with 
high oceanic heat content and the cyclone's well-defined low-level 
structure, rapid intensification (RI) is a realistic possibility, 
and some guidance is showing a 50/50 chance of RI during the next 
24 hours.  The NHC official intensity forecast hedges on the high 
side of the guidance but stops just short of showing explicit RI 
given the uncertainties on how much vertical shear will decrease.  
Continued strengthening could occur through day 3, but colder 
waters are likely to induce weakening on days 4 and 5. 


INIT  16/0300Z 13.2N 102.0W   35 KT  40 MPH
 12H  16/1200Z 13.9N 103.1W   50 KT  60 MPH
 24H  17/0000Z 14.6N 104.7W   60 KT  70 MPH
 36H  17/1200Z 15.2N 106.2W   75 KT  85 MPH
 48H  18/0000Z 16.0N 107.9W   85 KT 100 MPH
 60H  18/1200Z 16.7N 109.9W   85 KT 100 MPH
 72H  19/0000Z 17.2N 112.1W   85 KT 100 MPH
 96H  20/0000Z 18.8N 116.8W   80 KT  90 MPH
120H  21/0000Z 20.8N 121.1W   65 KT  75 MPH

Forecaster Berg

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