Port Isabel, Texas Weather Forecast Discussion

746
FXUS64 KBRO 200541 AAA
AFDBRO
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1241 AM CDT Sat Sep 20 2025
...New AVIATION...
.DISCUSSION...
Issued at 1045 PM CDT Fri Sep 19 2025
An unsettled weather pattern continues this weekend into next week
as upper level divergence persists and a series of mid-level
disturbances pass over Deep South Texas along the eastern periphery
of a mid-level high pressure centered over northwestern Mexico. The
same pattern over the past several days continues with convection
developing along the seabreeze boundary by mid-day across the
coastal areas, gradually pushing westward throughout the afternoon
and early evening hours before dissipating throughout the evening
and overnight hours, though overnight convection over the Gulf could
spill inland at times. PWAT values of around 1.6-2.0 inches are
likely to persist across the region through this weekend, highest
along the coast. As such, a low to medium (20-50%) chance of showers
and thunderstorms are likely today and tomorrow, mainly across the
eastern half of the northern ranchlands as well as the lower and mid
RGV, with the greatest chances east of I-69 E. Lightning, gusty
winds and heavy rain are possible, especially closer to the coast
where PWAT`s are highest. Additional minor flooding is possible
within the heaviest rain brought by slow-moving thunderstorms, which
have resulted in flood advisories for portions of the lower RGV the
past 2 days. Meanwhile, a less than 20% is anticipated across the
upper RGV and Rio Grande Plains, where PWAT`s are the driest/lowest.
Monday and Tuesday, PoP`s lower slightly, though still remain a low
to medium (20-40%) chance along and east of US-281/I-69C as the mid-
level high shifts eastward into western Texas. However,
probabilities rebound to a medium (40-60%) chance across all of Deep
South Texas on Wednesday as a cold front pushes into, and stalls,
across southern-central Texas before lifting northward and away from
the CWA into the weekend, thus lowering PoP`s to a low (20-30%)
chance. Lightning, gusty winds and brief heavy rain remain
possible.
Near-average high temperatures gradually rise to slightly above
average throughout the remainder of this weekend and into the middle
of next week, with mid/upper 90`s across inland Deep South Texas and
lower 100`s across portions of the upper RGV and Rio Grande Plains
by Monday and Tuesday. As clouds build and chances of rain
increase across the region towards the later part of the week,
temperatures gradually cool by a few degrees, though still
remaining above average further inland. Mostly minor (level 1 of
4) heat risks, with pockets of moderate (level 2 of 4), continue
through tomorrow before becoming a mainly moderate heat risk,
with pockets of major (level 3 of 4), Monday through Wednesday and
minor to moderate Thursday through Saturday.
&&
.AVIATION...
(06Z TAFS)
Issued at 1233 AM CDT Sat Sep 20 2025
Primarily VFR through the TAF cycle outside of any isolated to
scattered convection passing over airfields. A round of showers
in the morning is possible at all sites, more confident in HRL and
BRO, however, there is a possibility these start prior to what`s
indicated in PROB30 (as early as 10Z). Showers and storms along
the sea breeze are expected late this morning through the
afternoon, which carry the risk of gusty winds, lightning, and
heavy rainfall to all sites. Primarily easterly winds, light
overnight, may shift from northerly to southeasterly during the
day as outflow boundaries propagate from storms/showers.
&&
.MARINE...
Issued at 1045 PM CDT Fri Sep 19 2025
Slight to moderate (2-3 ft) seas prevail into next week as a result
of gentle easterly to southeasterly winds, becoming gentle to
moderate southeasterly to southerly winds on Monday. Chances of
showers and thunderstorms continue.
&&
.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             91  77  92  78 /  50  20  60  20
HARLINGEN               92  74  93  74 /  50  20  50  10
MCALLEN                 96  77  97  78 /  40  10  30  10
RIO GRANDE CITY         96  74  97  75 /  30  10  10   0
SOUTH PADRE ISLAND      87  81  88  81 /  40  30  60  30
BAYVIEW/PORT ISABEL     89  77  90  77 /  40  30  60  20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
SHORT TERM...65-Irish
LONG TERM....65-Irish
AVIATION...69-HK

NWS bro Office Area Forecast Discussion