Mc Allen, Texas Weather Forecast Discussion

887
FXUS64 KBRO 271720
AFDBRO
Area Forecast Discussion
National Weather Service Brownsville TX
1220 PM CDT Sat Sep 27 2025
...New DISCUSSION, AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1212 PM CDT Sat Sep 27 2025
- The rest of the weekend should be overall dry, with a small
   chance of a shower or two along the coast.
- Rain chances slightly increase on Monday and Tuesday, with a
   20-30% chance of isolated showers and thunderstorms along the
   sea breeze E of US 281/I-69C.
- Seasonal temperatures with a Minor (level 1 of 4) Heat Risk are
   expected throughout the week.
&&
.DISCUSSION...
Issued at 1212 PM CDT Sat Sep 27 2025
A frontal boundary remains stalled south of the Rio Grande Valley,
continuing overall dry conditions throughout Deep South Texas. This
should continue through the rest of the weekend, with a small chance
(15% or less) of an isolated shower or two along the coast for
Sunday. On Monday and Tuesday, a little more moisture returns to the
region as the frontal boundary exits the area and minor surface
troughing develops to the south. This slightly increased moisture,
along with daily diurnal heating, will result in increased chances
(around 20-30%) of a few isolated afternoon showers and
thunderstorms along the sea breeze boundary for areas east of US
281/I-69C.  Chances drop down again to less than 15% for coastal
areas Wednesday and Thursday, before picking up again to around 30%
for next weekend.
Temperatures for Deep South Texas are expected to be around
seasonable, with daily highs getting up into the low to mid 90s.
Areas in the Western Ranchlands could see highs in the upper 90s,
particularly around the end of next week.  Low temperatures should
go down into the low to mid 70s for the Rio Grande Valley, with
areas in the upper Ranchlands seeing lows in the upper 60s. Because
the front has pushed some of the subtropical humidity out of the
area for the time being, Heat Risk is expected to remain Minor
(level 1 of 4) throughout the weekend into next week.  Overall
mostly sunny to partly cloudy skies are expected throughout the next
week.
&&
.AVIATION...
(18Z TAFS)
Issued at 1212 PM CDT Sat Sep 27 2025
VFR conditions with few clouds expected at all airports and light
to moderate northeasterly winds.
&&
.MARINE...
Issued at 1212 PM CDT Sat Sep 27 2025
Marine conditions are expected to be favorable for the next seven
days. Winds are expected to be light to moderate and remain east-
northeasterly throughout the week.  In addition, low wave heights
between 1-3 feet are expected throughout the forecast period.
&&
.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             73  89  74  89 /  10  20  20  30
HARLINGEN               68  91  69  91 /   0  10  10  30
MCALLEN                 72  94  72  95 /   0  10  10  20
RIO GRANDE CITY         68  94  69  94 /   0   0   0  10
SOUTH PADRE ISLAND      78  86  79  86 /  10  20  20  30
BAYVIEW/PORT ISABEL     73  88  74  87 /  10  10  20  30
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
SHORT TERM...55-MM
LONG TERM....55-MM
AVIATION...55-MM

NWS BRO Office Area Forecast Discussion