The National Hurricane Center in Miami upgraded the system to Tropical Storm Bertha at 10:00 PM CDT Monday, July 20, 2026, after reconnaissance flights confirmed the storm had strengthened enough to earn tropical storm status.
Both NOAA and Air Force Hurricane Hunter aircraft measured flight-level winds near 35 knots within the storm’s convection to the southwest and southeast of the center. Forecasters also noted that the central pressure has dropped approximately 6 millibars since earlier in the afternoon. The storm has developed better organization, with an area of deep convection over its southern half and limited curved bands of storms in the northwestern quadrant. Upper-level outflow is well-defined to the south and southwest, though it remains restricted over the northern half of the storm.
As of Monday night, Bertha is moving very little — essentially stationary — based on multiple center fixes from the aircraft showing slow and erratic movement. The storm is caught between two mid-level subtropical high pressure systems in an area of weak steering winds. Forecasters expect the high pressure system to the northwest to become the dominant steering force, eventually pushing Bertha on a west-northwestward or westward track over the next several days. The official track forecast aligns closely with the previous National Hurricane Center prediction and the Google DeepMind ensemble mean.
Bertha is currently battling significant north-northeasterly vertical wind shear, and computer models suggest that shear will increase over the next couple of days. That hostile upper-level environment is expected to limit how much the storm can strengthen before it reaches the coastline. Model simulations also show the storm’s deep convection remaining near or just offshore due to the shear. Unfavorable atmospheric conditions, combined with the effects of land interaction, are expected to prevent further strengthening later in the forecast period. The official intensity forecast sits on the higher end of what the models are suggesting.
Here are the key messages issued by the National Hurricane Center:
Tropical Storm Conditions: Bertha is expected to bring tropical storm conditions to portions of the Gulf Coast from Alabama westward to southeastern Louisiana on Tuesday night and into Wednesday. A Tropical Storm Warning is in effect for that stretch. A Tropical Storm Watch is in effect for portions of the Florida Panhandle, the Metro New Orleans area, and the southern Gulf Coast of Louisiana.
Storm Surge Threat: A Storm Surge Watch is in effect for the coasts of Alabama, Mississippi, and southeastern Louisiana, where a life-threatening storm surge is possible.
Additional Watches Possible: Residents and interests elsewhere in Louisiana and Texas should closely monitor this storm’s progress, as additional watches or warnings may be issued for parts of those areas on Tuesday.
Flash Flooding Risk: Flash flooding is possible through Thursday along the Gulf Coast and nearby inland areas from western Florida — north of Fort Myers — to southern Louisiana. Isolated flash flooding could extend westward into portions of the Texas coast later in the week.
This forecast discussion was prepared by Forecaster Pasch at the National Hurricane Center.
