Advisories

000
WTNT42 KNHC 212057
TCDAT2
 
Tropical Storm Bertha Discussion Number  10
NWS National Hurricane Center Miami FL       AL022026
400 PM CDT Tue Jul 21 2026
 
Bertha remains a sheared tropical storm. The low-level center is 
exposed again, with bursts of deep convection displaced to the south 
by strong northerly shear. Scatterometer data from around 1520 UTC 
indicated that the extent of the tropical-storm-force wind field was 
larger than previous estimates, and the initial wind radii have been 
expanded as a result. Surface observations today showed that 
tropical-storm-force winds spread across some coastal portions of 
the Florida Panhandle. The central pressure has leveled off around 
995 mb based on the last aircraft pass through the center, and the 
intensity is held at 50 kt based on earlier aircraft data. This 
could be a bit generous, but an Air Force Reserve Hurricane Hunter 
mission scheduled for tonight will help reassess the intensity.

After moving northward earlier today, Bertha appears to have resumed 
a northwestward motion (305/5 kt). A mid-level ridge over the 
central United States is expected to build eastward on Wednesday to 
the north of Bertha. This should become the dominant steering 
feature and cause Bertha to move generally westward through midweek. 
This track will take the center of the storm near or along the 
northern Gulf Coast and toward southeastern Louisiana on Wednesday. 
From there, it is still unclear whether Bertha will survive its 
interaction with land and/or redevelop under hostile conditions. The 
GFS and UKMET models show the potential for center redevelopment off 
the coast of Louisiana late Wednesday, while the ECMWF and Canadian 
models favor a more inland solution with steady weakening. A notable 
change is that the track guidance this cycle trended faster, and the 
NHC forecast was sped up between 24-60 h to catch up to the simple 
and multi-model consensus aids. Otherwise, there was little 
cross-track change with this forecast update.

Based on its current structure and unrelenting shear, additional 
strengthening seems unlikely. While convection should continue 
pulsing to the south of Bertha's center, the NHC forecast shows 
gradual weakening during the next 2-3 days in agreement with the 
bulk of the intensity guidance. While this forecast shows Bertha 
surviving as a sheared tropical cyclone across the northern Gulf, it 
remains possible that the system degenerates into a trough over 
southern Louisiana sooner than forecast.

Based on the latest forecast updates, Tropical Storm Watches and 
Warnings have been extended westward along the coast of Louisiana.
 
 
Key Messages:
 
1. Tropical storm conditions are expected to spread westward along 
portions of the northern Gulf Coast from the Florida Panhandle 
westward to southeastern Louisiana, including the Metro New Orleans 
area, through Wednesday night. Tropical storm conditions are 
possible for portions of the southwestern coast of Louisiana 
Wednesday night and Thursday.
 
2. A Coastal Flood Warning is in effect for the Mississippi and 
Louisiana coastlines, where moderate coastal flooding is expected. 
 
3. Interests elsewhere in extreme western Louisiana and along the 
Upper Texas Coast should monitor the progress of this system, as 
additional watches or warnings could be required for portions of 
that area.
 
4. Isolated areas of flash flooding will be possible through 
Thursday along the Gulf Coast from the western Florida Panhandle 
into southern Louisiana.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  21/2100Z 29.4N  87.2W   50 KT  60 MPH
 12H  22/0600Z 29.6N  87.9W   45 KT  50 MPH
 24H  22/1800Z 29.5N  89.3W   45 KT  50 MPH
 36H  23/0600Z 29.3N  91.4W   40 KT  45 MPH...NEAR THE COAST
 48H  23/1800Z 29.4N  93.4W   35 KT  40 MPH...OVER WATER
 60H  24/0600Z 29.8N  95.6W   30 KT  35 MPH...INLAND
 72H  24/1800Z 30.3N  97.6W   25 KT  30 MPH...POST-TROP/INLAND
 96H  25/1800Z...DISSIPATED
 
$$
Forecaster Reinhart