106
FXUS64 KBRO 040519 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1219 AM CDT Sun Oct 4 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1216 AM CDT Sun Oct 4 2026

- Heavy rainfall from showers and thunderstorms will be the
  primary concern this weekend into Tuesday which could lead to
  flash flooding, mainly across the mid to lower RGV and lower
  Texas coast.

- A Coastal Flood Statement is in effect tonight for tidal runup ahead
  of and after high tide at 222 AM. Life-threatening rip currents
  are expected by Sunday.

-A Small Craft Advisory is in effect early Sunday morning into Monday
 afternoon.

-There is a 20% chance of tropical development over the Bay of
 Campeche/Southwestern Gulf over the next 7 days.

&&

.DISCUSSION...
Issued at 1041 PM CDT Sat Oct 3 2026

The frontal boundary and developing coastal trough near the lower
Texas coast will continue to be the main weather driver through the
forecast period. As the the frontal boundary sits along or just
offshore the lower Texas coast, ample moisture will keep the threat
for rainfall in the forecast through early week. The main axis for
heavy rain will continue to be along the coast tonight into
Tuesday. PWATs remain around 2.5 inches which translates to the
potential for very heavy rainfall at times. We have seen rainfall
rates near 4"/hr at times tonight, but fortunately most of that
has remained offshore. However, if these rainfall rates fall over
land it could lead to localized flooding. Areas that see multiple
rounds of heavy rain and/or training precipitation will also be at
a higher risk for flooding. Higher end probabilities continue to
show a low (10%) chance of isolated 5 to 8 inch rainfall totals
across the coastal counties between tonight and Tuesday.

The Weather Prediction Center maintains a Slight Risk (at least 15
percent chance) for flooding rainfall for areas along and east of US-
281/I-69C through tonight, with a Marginal Risk (at least 5 percent
chance) for flooding rainfall for locations west. There remains
additional flooding concerns into early Tuesday, mainly along the
coast, with a Marginal to Slight Risk Sunday into Monday across most
of the Rio Grande Valley and lower Texas coast, and a Marginal Risk
along the coast Monday into Tuesday.

As we head into mid to late week, rain chances will continue as a
coastal trough remains just offshore, but activity will be more
diurnally driven. Given the rainfall over the past few days and what
is expected through early week, this activity could also lead to
isolated areas of flooding.

Temperatures will remain near to above normal through the period but
will not be quite as blisteringly hot as the previous week thanks
to rain and excess cloud cover.

Will continue to monitor beach and marine hazards through the
weekend, with a potential for tidal run-up near high tides
continuing tonight and an elevated risk of life-threatening rip
currents Sunday into next week. A Coastal Flood Statement has been
issued for tonight and may need to be issued Sunday night as well.

Finally, the National Hurricane Center is keeping an eye on the
southwestern Gulf/Bay of Campeche this week. There are some
indications an area of broad low pressure may form and with slow
topical development. Right now chances are at 0% over the next 2
days and 70% over the next 7 days. At this time we do not anticipate
any major impacts to Deep South Texas but will continue to monitor
the situation closely.

&&

.AVIATION...
(06Z TAFS)
Issued at 1216 AM CDT Sun Oct 4 2026

Challenging flying conditions are expected through the next 24
hours, with waves of moderate to heavy showers and low ceilings
with light to moderate winds. Pure VFR will be hard to find
through the next 24 hours.

&&

.MARINE...
Issued at 1041 PM CDT Sat Oct 3 2026

A slow-moving frontal boundary, coastal trough, and surface low
pressure along the lower Texas coast this weekend into next week
will lead to continued showers and thunderstorms through the period.
As the pressure gradient strengthens tonight into Sunday, adverse
marine conditions are expected, primarily across the northern
waters. A Small Craft Advisory has been issued for all northern
waters from 4 AM Sunday morning until 1 PM on Monday. Could see
some elevated winds in seas with any shower or thunderstorm
activity as well.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             88  77  87  76 /  90  80  90  80
HARLINGEN               86  73  86  71 /  90  90  80  60
MCALLEN                 85  74  86  74 /  90  90  80  40
RIO GRANDE CITY         84  73  86  72 /  90  80  70  30
SOUTH PADRE ISLAND      86  80  85  79 /  90  80  90  90
BAYVIEW/PORT ISABEL     88  76  87  75 /  90  90  90  80

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Advisory from 4 AM early this morning to 1 PM CDT
     Monday for GMZ135-155-175.

&&

$$