Weslaco, Texas Weather Forecast Discussion

849
FXUS64 KBRO 211719
AFDBRO
Area Forecast Discussion
National Weather Service Brownsville TX
1219 PM CDT Sun Sep 21 2025
...New DISCUSSION, AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1204 PM CDT Sun Sep 21 2025
- Rain and thunderstorm chances continue each day.
- Heat advisories are possible on Tuesday and Wednesday.
&&
.DISCUSSION...
Issued at 1204 PM CDT Sun Sep 21 2025
Unsettled weather continues to prevail across Deep South Texas and
the Rio Grande Valley. A series of weak midlevel disturbances, high
moisture content, and afternoon heating will lead to shower and
thunderstorm chances each day, primarily in the afternoon-
coinciding with peak heating. Highest rain chances for the first
half of the week will be today, with a 30-60% chance of showers
and thunderstorms. Slightly drier air filters in for Monday and
Tuesday, with rain chances generally between 20 and 40%. As we
head into midweek, a cold front moving into central Texas will
once again lead to increasing moisture content and thus an
increase in POPs. Rain chances will generally be 30-50% on
Wednesday, increasing to 50-70% on Thursday then decreasing again
for the end of the week into the weekend. There is still a bit of
uncertainty on if the front will make it through Deep South Texas.
The ECMWF continues to push the front through the region on
Thursday, while the GFS has it stall and wash out just north or
across the CWA on Thursday. The ECMWF also remains a bit drier of
the two solutions, but opted to generally stick with the NBM this
far out. Tweaks will likely be made in the coming days, especially
to rainfall chances and amounts. Any precipitation that falls
throughout the week will have the potential to produce locally
heavy rain that could lead to nuisance flooding, especially on
roadways and low lying areas.
Normal to slightly above normal temperatures are expected for the
first half of the week but as rain chances increase midweek and the
potential of a cold front moving through and increased rain
chances temperatures may be slightly below normal. Heat indices
will be highest on Tuesday and Wednesday between 105 and 110 with
some locations rising to around 112. Heat Advisories may be needed
Tuesday and Wednesday. Heat Risk will be Moderate (level 2 out of
4) to Major (level 3 out of 4) Monday through Wednesday.
A moderate risk of rip currents is expected at area beaches over
through at least Monday afternoon.
&&
.AVIATION...
(18Z TAFS)
Issued at 1204 PM CDT Sun Sep 21 2025
VFR conditions will prevail through the TAF period. Scattered
showers and thunderstorms are expected through this afternoon. As
with previous days, this activity will be hit and miss, so opted
for VCTS in the TAF package. If this activity does impact the
aerodromes, brief lowered visibilities will be possible.
&&
.MARINE...
Issued at 1204 PM CDT Sun Sep 21 2025
Generally favorable conditions with mostly light to moderate winds
and seas of 2 to 3 feet. Rain and thunderstorm chances will continue
on the waters off the lower Texas coast through the period. Any
shower or thunderstorm activity will lead to localized increased
winds and seas.
&&
.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             78  93  79  93 /  20  50  20  40
HARLINGEN               74  95  76  96 /  10  40  10  30
MCALLEN                 78  98  79 100 /  10  30   0  20
RIO GRANDE CITY         74  99  76 101 /   0  10   0  10
SOUTH PADRE ISLAND      82  89  82  89 /  30  50  40  30
BAYVIEW/PORT ISABEL     77  92  78  92 /  20  40  20  30
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
DISCUSSION/MARINE/AVIATION...68

NWS BRO Office Area Forecast Discussion