Eastern Pacific Basin Tropical Cyclones

Tropical Storm Frank Forecast Discussion


000
WTPZ42 KNHC 262043
TCDEP2

Tropical Storm Frank Discussion Number   3
NWS National Hurricane Center Miami FL       EP072022
400 PM CDT Tue Jul 26 2022

Convection near the center of Frank is struggling to organize, as 
several bursts since the prior advisory have been stripped away 
southwest of the center due to continued moderate northeasterly 
vertical wind shear. Cirrus from a more recent convective burst is 
currently covering the center. Today's scatterometer swaths just 
clipped the far eastern edge of Frank's circulation, and while there 
were some greater than 34-kt wind retrievals in ASCAT-B at around 
1700 UTC, these values may have been rain contaminated, especially 
compared to the much lower ASCAT-C values less than an hour prior.  
Dvorak intensity estimates this afternoon were a consensus 
T2.5/35-kt from TAFB, SAB, and ADT. The intensity will remain at 35 
kt for this advisory. 

The shear over Frank is not expected to abate for the next 36-48 
hours, and in fact may increase a bit more as suggested by the 
ECMWF-SHIPS guidance. Both the ECMWF and GFS simulated IR brightness 
temperature also show convection continuing to be focused down-shear 
of the low-level circulation during this time frame, limiting 
intensification. One additional complicating factor is that another 
system located west of Frank could also interact with the tropical 
storm, though Frank should remain the dominant cyclone. Even after 
the shear abates in around 3 days, it is unclear what type of storm 
structure Frank will have at that time, and if it can take full 
advantage of the more favorable environmental conditions. For these 
reasons, the intensity forecast remains on the conservative side, 
showing a pause in strengthening between 12-36 hours, and then 
gradual intensification beginning afterwards. The latest intensity 
forecast remains on the low end of the intensity guidance, and 
remains closest to the LGEM model. 

Frank continues to move just north of due west at 280/10 kt. This 
general motion and heading should not change too much over the next 
2-3 days as the storm remains steered by a large mid-level 
subtropical ridge to its north. A weakness in the ridge thereafter, 
as well as some possible interaction with the system west of Frank, 
may allow the storm to gain more latitude thereafter. The track 
guidance this cycle has shifted a bit north, and the latest track 
forecast follows suit, located roughly between the HCCA and GFEX 
aids.


FORECAST POSITIONS AND MAX WINDS

INIT  26/2100Z 11.8N 103.5W   35 KT  40 MPH
 12H  27/0600Z 12.1N 104.9W   40 KT  45 MPH
 24H  27/1800Z 12.5N 106.7W   40 KT  45 MPH
 36H  28/0600Z 12.9N 108.5W   40 KT  45 MPH
 48H  28/1800Z 13.4N 110.6W   45 KT  50 MPH
 60H  29/0600Z 13.8N 112.6W   50 KT  60 MPH
 72H  29/1800Z 14.3N 114.3W   60 KT  70 MPH
 96H  30/1800Z 15.9N 117.1W   75 KT  85 MPH
120H  31/1800Z 18.4N 120.0W   75 KT  85 MPH

$$
Forecaster Papin



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