710
WTNT42 KNHC 221452
TCDAT2

Tropical Storm Bertha Discussion Number 13
NWS National Hurricane Center Miami FL AL022026
1000 AM CDT Wed Jul 22 2026

Bertha's satellite presentation has continued to degrade this
morning, with all of the associated deep convection having been
pushed well to the southwest of the exposed surface center due to
strong deep-layer shear. That said, dropsonde data from NOAA and
Air Force Reserve Hurricane Hunter aircraft indicate that the
central pressure has changed very little from the previous
advisory. The NOAA aircraft measured a peak 750-mb flight-level
wind of 55 kt several hours ago, which equates to an initial
intensity of 45 kt. More recent aircraft data suggest those winds
may have decreased, but for now we'll continue to hold 45 kt in
anticipation of additional aircraft and scatterometer data over the
next few hours.

Bertha's center has been deviating a bit north of the forecast
track, and the current motion estimate is now 290/5 kt. Track model
guidance insists that Bertha should resume a westward motion today,
but wobbles and deviations like the current one are normal behavior
for such a highly sheared tropical cyclone. Once a westward motion
resumes, Bertha's center is likely to straddle the coast of
Louisiana through Thursday and then reach the upper Texas coast by
Thursday evening or night. The NHC track forecast lies along the
northern edge of the guidance suite, partially to account for the
recent northward jog and partially to closely follow the typically
reliable HCCA and GDMI guidance.

The expected weakening appears to be on the verge of starting, and
the main question for the forecast is how quickly will Bertha lose
intensity. Part of that equation is how much time the center will
spend over land, while the system also continues to contend with
strong northeasterly shear. The NHC intensity forecast maintains
Bertha as a minimal tropical storm through 36 hours (around the
time of a potential Texas landfall), but it's also possible that
the cyclone could weaken to a depression or remnant low by that
time. Like the track forecast, the intensity forecast is largely a
blend of the latest HCCA and GDMI guidance. A remnant low forecast
point is shown over Texas at 48 hours for continuity's sake, but
Bertha could have dissipated by that time.


Key Messages:

1. Tropical storm conditions are expected to continue along portions
of the northern Gulf Coast from the western Florida Panhandle to
southeastern Louisiana, including the Metro New Orleans area,
through tonight. Tropical storm conditions are possible for portions
of the southwestern coast of Louisiana and upper Texas coast
tonight through late Thursday.

2. A Coastal Flood Warning is in effect for the Mississippi and
Louisiana coastlines, where moderate coastal flooding is expected.

3. Isolated areas of flash flooding remain possible through Friday
morning along the central to western Gulf Coast from Northwest
Florida to southern Texas.


FORECAST POSITIONS AND MAX WINDS

INIT 22/1500Z 29.8N 88.6W 45 KT 50 MPH
12H 23/0000Z 29.6N 90.3W 40 KT 45 MPH...INLAND
24H 23/1200Z 29.5N 92.7W 35 KT 40 MPH...OVER WATER
36H 24/0000Z 29.4N 95.5W 35 KT 40 MPH...INLAND
48H 24/1200Z 29.0N 98.7W 25 KT 30 MPH...POST-TROP/REMNT LOW
60H 25/0000Z...DISSIPATED

$$
Forecaster Berg


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