Brownsville, Texas 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

964
FXUS64 KBRO 040536 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1236 AM CDT Mon May 4 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1232 AM CDT Mon May 4 2026

Key Messages:

 * Building high pressure increases temperatures from the
   mid/upper 80s on Monday to mid/upper 90s on Wednesday while
   also warming afternoon heat indices, or "real feel
   temperatures," to near 100-105 F on Tuesday and 105-110 F on
   Wednesday.

 * Minor (Level 1 of 4) Heat Risk on Monday escalates to a Moderate
   (Level 2 of 4) risk on Tuesday and a Moderate to Major (Level
   3 of 4) risk on Wednesday.

 * A cold front may pass through or stall late Wednesday night or
   Thursday, gradually increasing chances of rain to a low to
   medium (40-50%) chance Thursday night, followed by a daily low
   (15-25%) chance into this upcoming weekend.

 * A medium risk of rip currents continues through at least Monday
   afternoon.

&&

.DISCUSSION...
Issued at 1026 PM CDT Sun May 3 2026

A mid/upper level trough moves onshore the California coast on
Monday, pushing a high pressure aloft eastward over Mexico and to
the Gulf by midweek, aiding in increasing subsidence aloft and
minimizing cloud coverage over Deep South Texas into Wednesday.
Meanwhile, at the surface, lowering pressure falls over the Southern
Plains and the Sierra Madre lead to increasingly breezier onshore
southeasterly winds along/east of US-281, where gusts of 25-30+ mph
are possible Tuesday and Wednesday afternoons, which will build
relative humidity across the region. All these factors combined
cause temperatures to climb from the mid/upper 80s on Monday to
the mid/upper 90s on Wednesday, while also warming afternoon heat
indices from mainly 100-105 F on Tuesday to mostly 105-110 F on
Wednesday. Thus, Heat Risks deteriorate from a Minor Risk on
Monday to a Moderate Risk on Tuesday and a Moderate to Major risk
on Wednesday. The hottest indices are expected to be along the
southern border, stretching from the Middle to Upper RGV, where
apparent temperatures may briefly exceed these ranges by a few
degrees for an hour or two. Overnight lows warm from the 60s
tonight to the 70s for the remainder of the forecast, generally
ranging around 5-8 degrees above average.

Then, a bit of a pattern change brings *some* relief to end the
week. The trough mentioned above lifts northeastward over the
Southern Plains on Wednesday and surface high pressure and northerly
winds on the backside of the associated surface low push a cold
front into southern Texas, either passing through or stalling near,
or across, our CWA, possibly Wednesday night or Thursday morning
into Friday. Frontal lift and moisture pooling in conjunction with
enhancing forcing and ascension aloft, downstream of a slow-moving
upper level cut-off low to the west, are currently anticipated to
gradually increase chances of rain from late Wednesday night or
Thursday morning to as much as a medium (40-50%) chance Thursday
night as showers and thunderstorms develop. Despite increasing
chances of rain and clouds, Thursday afternoon temperatures and
heat indices could still reach into the lower 90s and lower 100s,
respectively, with a Minor to Moderate Heat Risk. Friday may be
the coolest day of the forecast as overcast skies could keep
temperatures in the 80s. Otherwise, temperatures gradually rise
back to the 90s by Sunday while a low (15-25%) chance of daily
diurnally-driven convection continues, with shower and thunderstorm
activity peaking in the afternoon.

Given that we are several days away from unsettled weather and
confidence is low at this point, we will be keeping a close eye for
any possibility of strong to severe thunderstorms and excessive
rainfall, beginning Wednesday night or Thursday and persisting
into this upcoming weekend, resulting from the front and/or mid-
level disturbances running out ahead of the cut-off low pressure
aloft behind the front.

Alongshore southeasterly winds and 3-4 foot waves with 6-7 sec.
periods result in a medium risk of rip currents through at least
Monday afternoon. Breezy winds throughout the week could continue
to result in a moderate or low risk.

&&

.AVIATION...
(06Z TAFS)
Issued at 1232 AM CDT Mon May 4 2026

A few mid to high level clouds and light southeast winds prevail
across Deep South Texas early this morning. Light southeast winds
overnight will increase and become gusty in the late morning and
afternoon. Some gusts between 20 to 25 knots will be possible in
the afternoon, especially at BRO/HRL. VFR conditions are expected
for the next 24 hours.

&&

.MARINE...
Issued at 1026 PM CDT Sun May 3 2026

Mainly moderate to fresh winds, moderate (3-5 ft) seas and periods
of Small Craft Exercise Caution headlines are likely through
Friday, with winds transitioning from southeasterly to northeasterly
or easterly on Thursday in association with a frontal boundary
passing through or stalling over the Lower Texas coast. Gentle to
moderate southeasterly winds resume over the weekend. Developing
showers and thunderstorms result increase in chances of rain
Thursday to as much as a low to medium (30-40%) chance Thursday
night into Friday. A lingering low (15-20%) chance lingers into
the weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             85  75  90  77 /   0   0   0   0
HARLINGEN               87  71  92  75 /   0   0   0   0
MCALLEN                 88  75  95  78 /   0   0   0   0
RIO GRANDE CITY         88  72  98  75 /   0   0   0   0
SOUTH PADRE ISLAND      80  76  83  77 /   0   0   0   0
BAYVIEW/PORT ISABEL     84  73  89  76 /   0   0   0   0

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&

$$

SHORT TERM...65-Irish
LONG TERM....65-Irish
AVIATION...63-KC