Tropical Storm Bertha

000
WTNT42 KNHC 211457
TCDAT2
 
Tropical Storm Bertha Discussion Number   9
NWS National Hurricane Center Miami FL       AL022026
1000 AM CDT Tue Jul 21 2026
 
Bertha has become slightly better organized this morning. While the 
low-level center was fully exposed overnight, new deep convection 
has developed this morning and the center has become at least 
partially tucked underneath the cold overcast. The Air Force 
Hurricane Hunters have been investigating the storm, and they 
reported peak 850-mb flight-level winds of 62 kt within the 
convection to the southeast of the center, along with layer-averaged 
dropsonde winds that support raising the initial intensity to 50 kt. 
The central pressure has fallen slightly to 995 mb.

Bertha has deviated north of the forecast track during the past 
several hours, and the initial motion is north-northwestward (345/3 
kt). The near-term track forecast has been adjusted northward to 
account for this development. While Bertha is currently in fairly 
weak steering currents, a mid-level ridge centered near the Rockies 
is expected to move southeastward during the next couple of days. 
This should cause Bertha to turn more west-northwestward and then 
westward while it moves near or along the northern Gulf Coast 
through midweek. While the track models are overall in good 
agreement on this scenario, there are differences in how much land 
interaction with southeastern Louisiana will occur, and whether a 
new center may redevelop off the coast. Little change was made to 
the NHC track forecast beyond 24 h, and once again this forecast 
assumes Bertha is able to maintain a cohesive circulation as it 
passes near or over the northern Gulf Coast.

Bertha remains an asymmetric tropical storm, with most of the 
rainfall and the strongest winds occurring to the south and east of 
the center. Strong northeasterly vertical wind shear over Bertha is 
forecast to persist today and tonight, which should make it 
difficult for Bertha to strengthen much more. Convection is expected 
to continue pulsing to the south of Bertha's center during this 
time, and the NHC forecast overall shows gradual weakening over the 
next few days. The extent of this weakening will depend on how much 
land interaction occurs during the next couple of days, and it 
remains possible that Bertha could degenerate into a trough even 
sooner than forecast due to a disrupted structure within hostile 
environmental conditions.

Some notable watch/warning changes were made with this advisory 
package. The Tropical Storm Warning was extended eastward across 
the Florida Panhandle and westward to the Terrebonne/Lafourche 
Parish Line in Louisiana. In addition, the Storm Surge Watch has 
been replaced with a Coastal Flood Warning issued by the local 
forecast office. Minor to moderate coastal flooding is still 
expected to occur between the Mississippi/Alabama Border and the 
Mouth of the Mississippi River, with peak values up to 4 ft above 
ground level.
 
 
Key Messages:
 
1. Bertha is expected to bring tropical storm conditions to portions 
of the Gulf Coast from the Florida Panhandle westward to 
southeastern Louisiana later today and Wednesday, where a Tropical 
Storm Warning is in effect. Tropical storm conditions are possible 
for Metro New Orleans and the southern Gulf Coast of Louisiana, 
where a Tropical Storm Watch is in effect.
 
2. A Coastal Flood Warning is in effect for the Mississippi and 
Louisiana coastlines, where moderate coastal flooding is expected. 
 
3. Interests elsewhere in Louisiana and Texas 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 Friday 
along the Gulf Coast from western Florida into southern Louisiana 
and the Upper Texas coast.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  21/1500Z 29.3N  86.3W   50 KT  60 MPH
 12H  22/0000Z 29.4N  87.0W   50 KT  60 MPH
 24H  22/1200Z 29.5N  88.0W   45 KT  50 MPH
 36H  23/0000Z 29.4N  89.5W   40 KT  45 MPH...NEAR THE COAST
 48H  23/1200Z 29.3N  91.3W   35 KT  40 MPH...NEAR THE COAST
 60H  24/0000Z 29.4N  93.1W   30 KT  35 MPH...OVER WATER
 72H  24/1200Z 29.9N  94.9W   25 KT  30 MPH...INLAND
 96H  25/1200Z 31.0N  97.5W   20 KT  25 MPH...POST-TROP/INLAND
120H  26/1200Z...DISSIPATED
 
$$
Forecaster Reinhart