Severe Thunderstorm Warning 91, NWS Brownsville, TX

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
630 PM CDT Sat Nov 1 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 609 PM CDT Sat Nov 1 2025

  - Isolated to scattered showers and thunderstorms are expected
    to develop ahead of the cold front throughout the late evening
    and late night hours tonight, rising probabilities of rain to
    a medium to likely (40-60%) chance across the eastern half of
    Deep South Texas.

 - The Storm Prediction Center (SPC) has outlined a Marginal
   (level 1 of 4) Risk, mainly along and east of US-281/I-69 C,
   and a Slight Risk (level 2 of 4) for the Northeastern parts of
   Kenedy County, for the possibility of isolated severe
   thunderstorms along the leading edge of convection, capable of
   producing large hail and damaging wind.

 - A medium risk for rip currents is likely tonight into Monday
   due to the increase in wind, wave heights and wave periods
   following the front as well as from the building influence of
   astronomical tides.

&&

.DISCUSSION...
Issued at 1215 PM CDT Sat Nov 1 2025

The advance of a surface cold front during the evening and overnight
hours will result in rain chances in the range of low to medium (20%-
60%). SPC does have most of the near and east of US-281/I-69C in a
marginal risk (level 1 of 4) for severe weather tonight. SPC has
recently upgraded parts of eastern Kenedy county into a Slight Risk
(2 of 4) for severe weather. While there still some uncertainty with
the area for the development of showers and thunderstorms overland.
The environmental setup with cold temperatures aloft and strong
northwesterly flow and deep-layer shear will provide some support
for the development of showers and thunderstorms. While the timing
for these showers and thunderstorms is still expected to be
primarily overnight, there is still a chance that the front and the
showers and thunderstorms associated with it could come sooner in
the evening. However, by tomorrow morning the rain chances are
expected to diminish.

After the front moves through Deep South Texas and the Rio Grande
Valley, the temperatures through Wednesday will be in the 80s with
each day the high temperatures furthering to increase. By Wednesday,
the 90s will return to the area, and further spread over the region
by the end of the forecast period.

Finally, while a low risk of rip currents is in present at the local
beaches today. Higher waves and swell is expected behind the front
that will increase the rip current risk to moderate through
Monday.

&&

.AVIATION...
(00Z TAFS)
Issued at 609 PM CDT Sat Nov 1 2025

Isolated to scattered showers with embedded isolated strong to
severe thunderstorms have developed north of the region in
association with an advancing cold front. Over the next few hours,
am anticipating for winds to gradually become light at KBRO and
KHRL along with a slight probability of light showers while KMFE
remains dry with moderate (10-15 knots) gusts. Late tonight, the
front and line of convection are expected to move south and
southeastward, bringing vicinity showers and thunderstorms to all
terminals, generally between 05-10Z, though time may vary by a few
hours. Due to uncertainty in timing and coverage in storms,
PROB30's are included for MVFR conditions as moderate to heavy
showers and thunderstorms are possible, with large hail (greater
than 1 inch) and damaging wind (possibly in excess of 50 knots)
being the primary threats within the strongest of storms. The
higher potential for isolated strong to severe thundrestorms are
at KHRL and KBRO during this timeframe.

As the storms pass by around 10Z, we expect moderate (10-15 knots)
northerly winds at all terminals in wake of the cold front
passage, with gusts up to 20 knots, increasing to as high as 25
knots during the day tomorrow. Prevailing VFR conditions return as
clouds clear early in the morning.

&&

.MARINE...
Issued at 1215 PM CDT Sat Nov 1 2025

A frontal boundary is likely to bring unsettled weather the to the
Lower Texas Coast, that could see some strong to severe
thunderstorms develop over the waters. Some of these storms could
produce large hail. These showers and thunderstorms could also
produce locally elevated winds and seas. Behind the front, Small
Craft Advisory conditions are expected to set in over the waters
with these conditions expected to persist through tomorrow
afternoon. After which, adverse conditions are expected to
diminish and by Sunday night, should start to trend to become more
favorable.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             66  79  60  81 /  70  10   0   0
HARLINGEN               59  80  52  82 /  70  10   0   0
MCALLEN                 61  83  57  85 /  40   0   0   0
RIO GRANDE CITY         58  82  51  85 /  20   0   0   0
SOUTH PADRE ISLAND      70  77  70  78 /  80  10   0   0
BAYVIEW/PORT ISABEL     65  78  61  80 /  80  10   0   0

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Advisory from 1 AM to noon CDT Sunday for GMZ130-132-
     135-150-155-170-175.

&&

SHORT TERM...64-Katz
LONG TERM....64-Katz
AVIATION...65-Irish