Brownsville, Texas 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

720
FXUS64 KBRO 282248 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
548 PM CDT Wed May 28 2025

...New AVIATION...

.SHORT TERM...
(Tonight through Thursday night)
Issued at 215 PM CDT Wed May 28 2025

Deep South Texas will be under the influence of mid level ridging,
which will result in generally rain-free to fairly limited rain
chances (less than 20%) and warm temperatures. Mild nights tonight
and Thursday night are expected with lows in the mid 70s and partly
to mostly cloudy skies. Some patchy fog cannot be ruled out. The
combination of high temperatures in the mid 90s and humidity will
result in heat index values ranging from 100 to 109 degrees Thursday
afternoon. While this does not meet Heat Advisory criteria, there
will be a minor to moderate heat risk for most of the region.

&&

.LONG TERM...
(Friday through next Wednesday)
Issued at 215 PM CDT Wed May 28 2025

Key Messages:

*There is a low to medium chance of showers and thunderstorms Friday
into Sunday in association with a frontal boundary.

*The Storm Prediction Center (SPC) has included all of deep south
Texas and the Rio Grande Valley within a Marginal Risk (level 1/5)
for isolated severe thunderstorms during the daytime on Friday ahead
of the front.

*Reduced heat indices and mostly minor heat risks (level 1/4) Friday
through Sunday increase Monday into Wednesday, resulting in heat
indices as high as 105-110 degrees and mostly a moderate heat risk
(level 2/4) into the middle of next week.

Unsettled weather is anticipated for the first half of the long term
as ridging and subsidence aloft remain minimized due to a mid/upper
level trough over the eastern US and a mid/upper level cut-off low
offshore the Baja California peninsula. A cold front, attached to a
departing surface low pressure system over the mid-Atlantic, is
expected to sag southward through southern-central Texas throughout
Friday before stalling over deep south Texas by Saturday morning,
possibly over the northern ranchlands and the Rio Grande Plains, as
a stationary boundary. As the front draws closer, surface
convergence and lift will enhance as winds shift from southeasterly
to easterly by Friday evening. This will increase probabilities of
showers and thunderstorms from a low to medium (20-30%) chance
Friday afternoon to 20-50% Friday night, mostly west of I-69 E, with
the highest probabilities over the Rio Grande Plains. SPC has
included all of deep south Texas and the Rio Grande Valley within a
Marginal Risk (level 1/5) on Friday, noting that "isolated (severe)
thunderstorms may develop along and ahead of a cold front" as low
level lapse rates remain steep, allowing for deep upscale growth as
well as mention that due to weak deep-layer shear, severe potential
should diminish Friday evening as daytime heating subsides. On
Saturday and Sunday, more widespread convection is possible (20-40%
chance) as the stationary boundary lingers across the region.
Southeasterly winds return on Sunday and probabilities of showers
and thunderstorms decrease from 20-30% on Monday to 20% on Tuesday
to less than 15% by Wednesday as ridging and subsidence build aloft.

Near to slightly above average highs on Friday (lower to mid 90s)
dip to slightly cooler than average on Saturday (upper 80s to low
90s) as clouds increase and then gradually trend warmer Sunday
through Wednesday as clouds decrease; lower to mid 90s on Sunday and
Monday warm to as high as upper 90s on Tuesday and to near 100
degrees on Wednesday for portions of the mid and upper RGV as well
as Zapata County. Lows in the 70s are expected for the period, to
possibly as high as lower 80s across lower RGV by Monday night.
Mostly a minor heat risk (Level 1/4) is expected Friday through
Sunday, increasing to a moderate heat risk (level 2/4) Monday
through Wednesday as heat indices rise back to 105-110 degrees.
Temperatures will range from low to high 80s at the beaches.

&&

.AVIATION...
(00Z TAFS)
Issued at 548 PM CDT Wed May 28 2025

Through 00z Friday....Mostly VFR conditions are expected to prevail
through the 00z TAF cycle. There could be a few MVFR to maybe even
IFR clouds around, especially tonight due to the combined effects of
radiational cooling and high low level water vapor content from
recent rains.

Winds will be out of the southeast 5-10 kts through the forecast
period.

&&

.MARINE...
Issued at 215 PM CDT Wed May 28 2025

Tonight through Thursday night...Generally favorable marine
conditions are expected in wake of this morning`s showers and
thunderstorms. Expect low to moderate seas and light to moderate
east to southeast winds through the period. Small Craft Exercise
Caution conditions cannot be ruled out during the afternoon hours
tomorrow across the Laguna Madre and nearshore Gulf waters.

Friday through next Wednesday...Gentle to moderate southeasterly
winds and slight to moderate seas on Friday become mostly gentle
easterly winds with slight seas Friday evening into Saturday night,
becoming southeasterly by Sunday morning. Gentle to moderate winds,
moderate seas and potential Small Craft Exercise Caution conditions
return by Tuesday as a slight pressure gradient develops. There is
at least a 20-30% daily chance of showers and thunderstorms through
the period with the highest chances on Saturday (30-40%) as a
stationary boundary lingers over the Lower Texas coastal waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             78  92  79  93 /  20  10   0  20
HARLINGEN               76  94  77  94 /  10  10   0  20
MCALLEN                 78  97  79  97 /  10  10   0  20
RIO GRANDE CITY         76  95  76  95 /  20   0   0  30
SOUTH PADRE ISLAND      80  86  80  87 /  20  10   0  10
BAYVIEW/PORT ISABEL     78  91  78  91 /  20  10   0  20

&&

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

$$

SHORT TERM...22-Garcia
LONG TERM....65-Irish
AVIATION...23-Evbuoma