Brownsville, Texas 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

667
FXUS64 KBRO 160353
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
1053 PM CDT Sun Mar 15 2026

...New KEY MESSAGES, DISCUSSION, MARINE, FIRE WEATHER...

.KEY MESSAGES...
Updated at 1047 PM CDT Sun Mar 15 2026

Key Messages:

* Strong cold front (modified Arctic airmass) arrives tonight;
  temperatures by Monday morning will have plummeted 40-50F degrees
  from Sunday afternoon`s highs.

* Strong to potentially damaging winds develop tonight into Monday;
  northerly winds 25-35 mph are expected to gust as high as 45-55
  mph with local gusts as high as 55-60 mph.

* A Red Flag Warning (RFW) for a critical fire weather risk is in
  effect for all of Deep South Texas, excluding the island till 7 PM
  CDT Monday; Fire Danger ranges between Very High and Extreme.

* Hazardous marine/coastal conditions likely though Monday; A Gale
  Warning is in effect for the Laguna Madre and Gulf Waters till 7
  PM CDT Monday.

&&

.DISCUSSION...
Issued at 1047 PM CDT Sun Mar 15 2026

After today`s heat spike, which resulted in McAllen tying it`s
record high of 103F set back in 2008, courtesy of strong
compressional heating from a nearby dryline and strong southerly
winds, a significant change to the weather pattern is just about
underway for all of Deep South Texas and the Rio Grande Valley.

Driven by an anomalously strong and emerging 591-591 dam Sonoran
heat ridge over the Southwestern U.S. and a mature (neutrally-
tilted) powerhouse mid-latitude cyclone over the Midwest/Great
Lakes Region, that`s producing combination of blizzard conditions
in it`s cold sector and severe weather in it`s warm sector, a very
strong cold front (modified Arctic front) will sweep through all
of Deep South Texas and the Rio Grande Valley tonight.

Accompanying this cold front will be a 40-50F degree drop off in
temperatures from this afternoon to Monday morning along with strong
to damaging northerly winds 25-35 mph gusting as high as 45-55 mph
late tonight into Monday. There could be an isolated case where wind
gusts reach 55-60 mph. Multiple hazards, including fire weather
and coastal/marine are in effect through the day on Monday in
response to the Arctic front and impending weather changes.

Latest radar scans and sfc analysis shows the cold front quickly
advancing southward over Corpus Christi`s county warning area (CWA)
and knocking on the doors of the Northern Ranchlands. Expect for
this cold front to push through Deep South Texas from north to south
between midnight and 4am. Along and behind the cold fropa, an
enhanced pressure and thermal (isollabaric) gradient will result
in strong to at times damaging winds. North-northeast winds 25-35
mph are expected to gusts as high as 45-55 mph with isolated
gusts up to 60 mph. Isolated power outages are possible, so be
prepared. A WIND ADVISORY remains in effect for all of Deep South
Texas till 8 AM CDT and for Brooks, Kenedy, Hidalgo, Willacy, and
Cameron counties till 1 PM CDT Monday.

Through tonight, following the cold fropa, temperatures will plummet
as these winds will usher in a modified Arctic airmass into the
region. By Monday morning, wake up temperatures will be in the upper
40s across parts of the Northern Ranchlands to the mid 50s along the
Rio Grande Valley. Amid additional cool air advection (CAA) and the
modified Arctic airmass still building into the region, Monday will
feature the coolest day of the week with daytime highs struggling to
make it out of the 60s, some 30-40F degrees cooler than the highs on
Sunday, and ~15F degrees cooler than normal. With the cool airmass
fully locked in over the region on top or sufficient radiational
cooling on clearing skies, a cold night looms Monday night with
overnight lows mainly in the 40s with 50s found along/near the
coast.

Low relative humidity (RH) values and windy conditions on top of an
ongoing drought will result in critical fire weather risk with the
potential for fuels becoming combustible upon fire ignition on
Monday across Deep South Texas. A Red Flag Warning (RFW) remains in
effect for all of Deep South Texas, excluding the island from 10 PM
CDT tonight to 7 PM Monday (see FIRE WEATHER SECTION for more
details). These strong winds will also create hazardous marine and
coastal conditions tonight through Monday (SEE MARINE SECTION for
more details).

Beyond Monday night, a warming trend is expected to take place
through the remainder of the forecast period. By Thursday,
temperatures are expected to return to unseasonable warm levels
(80s/90s) across Deep South Texas and the Rio Grande Valley.

&&

.AVIATION...
(00Z TAFS)
Issued at 622 PM CDT Sun Mar 15 2026

Through 00z Tuesday....The main weather concern to aviation ops for
the terminals through the forecast period will be the strong to
potentially damaging northerly winds developing later tonight into
Monday, which will likely have major impacts/implications particularly
to east to west oriented runways.

VFR conditions, by and large, will prevail through the 00z TAF cycle.
There could be a few MVFR-LIFR clouds at times, particularly tonight.

Ahead of an approaching cold front, winds will continue out of the
south with speeds between 7-15 kts, occasionally gusting as high
as 20 kts through the evening hours before fading. In response to
the cold fropa later this tonight, winds will shift out of the
north and become strong with speeds between 15-25 kts. Winds will
gusts generally between 35-45 kts, however, there could be
isolated gusts as high as 50 kts or so on Monday.

&&

.MARINE...
Issued at 1047 PM CDT Sun Mar 15 2026

A Gale Warning is in effect for the Laguna Madre and Gulf Waters
till 7 PM CDT Monday. North-northeast winds 25-35 knots gusting up
to 40 knots or so is expected. This will drive up high seas with
wave heights ranging between 13-18 feet. Monday night through
Tuesday, marine conditions (seas) will improve in response to the
return of lighter winds. By Wednesday, favorable marine conditions
are expected to return with low to moderate winds and seas.
Favorable marine conditions will prevail through the remainder of
the forecast period.

&&

.FIRE WEATHER...
Issued at 1047 PM CDT Sun Mar 15 2026

A Red Flag Warning (RFW) is in effect for all of Deep South Texas,
excluding the island till 7 PM CDT Monday. The combination of low
relative humidity (RH) values, windy conditions, and an ongoing
drought ranging from D2 Severe to D4 Exceptional, will result in
critical fire weather risk on Monday. Any fires that ignite under
these conditions will have the potential to become combustible and
rather aggressive. We continue to urged everyone to not burn on
Monday and continue to exercise safe fire weather conditions.

The Texas A&M Forest Service has outlooked the region under a
Very High to Extreme Fire Danger for Monday. Energy Release
Component (ERC) values will be high across the region on Monday
ranging between 75- 100%. Finally, fuels will be dry to critically
dry on Monday.

Additional fire weather concerns are possible through next weekend
due to a continuation of at times low relative humidity levels and
breezy conditions, in addition to an ongoing drought.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             59  64  53  72 /  20   0  10  10
HARLINGEN               52  66  47  72 /  10   0   0   0
MCALLEN                 55  68  49  76 /  10   0   0   0
RIO GRANDE CITY         52  68  47  75 /   0   0   0   0
SOUTH PADRE ISLAND      59  62  58  67 /  20  10  10  10
BAYVIEW/PORT ISABEL     56  63  53  70 /  20   0   0  10

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Red Flag Warning until 7 PM CDT Monday for TXZ248>255-351-
     353>355.

     Wind Advisory until 8 AM CDT Monday for TXZ248-249-252.

     Wind Advisory until 1 PM CDT Monday for TXZ250-251-253>255-351-
     353>355-451-454-455.

     High Rip Current Risk from 7 AM CDT Monday through Monday
     evening for TXZ451-454-455.

     High Surf Advisory from 7 AM to 7 PM CDT Monday for TXZ451-454-
     455.

GM...Gale Warning until 7 PM CDT Monday for GMZ130-132-135-150-155-
     170-175.

&&

$$

SHORT TERM...23-Evbuoma
LONG TERM....23-Evbuoma
AVIATION...23-Evbuoma