Heidelberg, Texas Weather Forecast Discussion

817
FXUS64 KBRO 091735
AFDBRO
Area Forecast Discussion
National Weather Service Brownsville TX
1235 PM CDT Tue Sep 9 2025
...New DISCUSSION, AVIATION, MARINE...
.DISCUSSION...
Issued at 1235 PM CDT Tue Sep 9 2025
Daily low to medium (30-50%) rain chances will continue across
most of Deep South Texas through the end of the week and into the
weekend. The 12Z upper air sounding measure precipitable water
values around 2.14 inches, which is right at the 90th percentile
for this date according to SPCs sounding climatology page. In
combination with diurnal instability and a lingering stationary
boundary, isolated to scattered showers and thunderstorms are
expected to develop from the mid morning hours to early evening
hours each day across the region. Over the Gulf waters and near
the Lower Texas beaches, isolated activity is expected into the
evening and overnight hours. In general, the highest precipitation
chances each day will reside closer to the immediate coast, which
coincides with the highest precipitable water values. Given the
presence of high moisture content, pockets of brief heavy rainfall
cannot be ruled out with any showers or thunderstorms that
develop. This may result in nuisance flooding issues, mainly over
low-lying or flood-prone areas depending on where the activity
sets up. Rain chances look to decrease over the weekend as
subsidence increases aloft. Any activity should be limited to
mostly sea breeze activity during the early afternoon to early
evening hours.
Expect seasonable temperatures to continue through the next week
or so with highs in the low to mid 90s region wide. In combination
with the humidity, heat index values are expected to range from
100 to 105 degrees. Fortunately, increased cloud cover associated
with any showers or thunderstorms may help keep temperatures a few
degrees cooler than forecast. A minor (level 1 of 4) heat risk
will continue through the weekend.
&&
.AVIATION...
(18Z TAFS)
Issued at 1235 PM CDT Tue Sep 9 2025
VFR will prevail through the forecast period at all TAF sites.
However, brief periods of MVFR ceilings/visibility, gusty winds,
lightning and/or brief heavy rainfall cannot be ruled out this
afternoon as isolated to scattered convection develops. Confidence
on the exact location and timing is low, but have opted to include
VCSH through early this evening as conditions are favorable for
showers. Amendments may be needed for any isolated thunderstorms
that develop near the terminals.
&&
.MARINE...
Issued at 1235 PM CDT Tue Sep 9 2025
Generally favorable marine conditions will prevail with light to
moderate easterly winds and low to moderate seas. Medium to high
rain chances continue through the end of the week over the Gulf
waters and Laguna Madre. Locally enhanced winds and seas are
likely within any showers and thunderstorms.
&&
.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             78  92  78  92 /  50  50  40  60
HARLINGEN               74  92  74  93 /  30  50  30  60
MCALLEN                 77  95  77  95 /  30  50  30  60
RIO GRANDE CITY         74  96  74  95 /  10  50  20  50
SOUTH PADRE ISLAND      81  87  81  88 /  60  60  40  60
BAYVIEW/PORT ISABEL     77  90  77  90 /  50  50  40  60
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
SHORT TERM...22-Garcia
LONG TERM....22-Garcia
AVIATION...22-Garcia

NWS BRO Office Area Forecast Discussion