Tropical Cyclone Discussion

865
WTPZ42 KNHC 282035
TCDEP2
 
Tropical Storm Lowell Discussion Number   5
NWS National Hurricane Center Miami FL       EP122026
1100 AM HST Fri Aug 28 2026

Lowell continues to be affected by easterly vertical shear. The 
low-level center is currently exposed to the east of the main 
convective mass, and satellite imagery is hinting that the 
mid-level center is west or southwest of the low-level center. A 
recent ASCAT overpass showed no tropical-storm force winds in the 
eastern semicircle, but it did not sample the winds under the 
deep convection.  Satellite intensity estimates range from 30-45 
kt, and the initial intensity is held at 40 kt. 

Lowell is starting its forecast westward turn. The initial motion 
is 305/4 kt, and the cyclone should start a westward motion within 
the next 12 h. A general westward motion should continue for the 
next 2-3 days as a low- to mid-level ridge to the north of Lowell 
becomes the primary steering influence.  The forecast uncertainty 
becomes quite large by 120 h due to the possible effect of the 
larger Tropical Storm Storm Karina on Lowell's steering currents. 
The track guidance has a significant spread in Lowell's forward 
speed between the faster HCCA/UKMET/Google DeepMind Ensemble Mean 
and the slower ECMWF/Canadian/GFS.  The new track forecast leans 
towards the faster models, and it is a little south of the previous 
forecast.

The current shear is expected to decrease in 18-24 hours. After 
that time, conditions appear generally favorable for strengthening, 
with the caveat that water vapor imagery shows mid- to upper-level 
dry air not far north of the cyclone's forecast track. The 
intensity forecast shows only modest strengthening during the next 
24 h due to the shear and Lowell's current poor level of 
organization. After that, a faster rate of development is likely, 
particularly after 60 h. The intensity near the end of the forecast 
period is dependent on how close Lowell is to Karina. The current 
faster track forecast keeps the cyclones farther apart and thus 
Lowell is forecast to continue strengthening. However, if the 
slower track guidance is correct, Lowell could wind up in stronger 
shear and with a lower intensity due to proximity to Karina.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  28/2100Z 12.5N 133.4W   40 KT  45 MPH
 12H  29/0600Z 12.6N 134.0W   40 KT  45 MPH
 24H  29/1800Z 12.8N 135.4W   45 KT  50 MPH
 36H  30/0600Z 13.0N 136.9W   50 KT  60 MPH
 48H  30/1800Z 13.1N 138.6W   55 KT  65 MPH
 60H  31/0600Z 13.4N 140.5W   65 KT  75 MPH
 72H  31/1800Z 13.6N 142.4W   75 KT  85 MPH
 96H  01/1800Z 14.1N 145.6W   90 KT 105 MPH
120H  02/1800Z 14.7N 149.0W   95 KT 110 MPH