140
FXUS64 KBRO 301725
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
1225 PM CDT Sat Aug 30 2025

...New DISCUSSION, AVIATION, MARINE...

.DISCUSSION...
Issued at 1216 PM CDT Sat Aug 30 2025

The main concern for this holiday weekend continues to be the heat.
With a mid-level ridge over Deep South Texas and the Rio Grande
Valley, and low-level southerly to southeasterly flow advecting more
low-level moisture into the region. These factors result in higher
temperatures and higher heat indices as well. With nearly a majority
of the CWA in a major (level 3 of 4) heat risk, and the rest of the
region in a moderate (level 2 of 4). With the range of the heat
indices in the range of 105 to 110 for today through Monday,
additional Special Weather Statements could be issued for elevated
heat indices. For resources on staying safe in the heat, visit
weather.gov/heatsafety.

With the previously mentioned mid-level ridge over the area, the
chances for rain will remain low (less than 20%) for the next couple
of days. However, a frontal boundary is expected to move southward
and stall towards the north of the CWA. With the southerly to
southeasterly low-level moisture flow expected at this time, there
will be an opportunity for moisture to pool ahead of the boundary
and allow for the development of showers and thunderstorms. Add in
some instability from the diurnal heating as well, and the
environment is capable of producing some showers and thunderstorms.
Current rain chances for Monday afternoon remain around medium (40-
60%). WPC has a small portion of the Northern Ranchlands in a
marginal risk (level 1 of 4). While the environmental conditons seem
favorable, the key to the forecast for the rain will be where the
frontal boundary stalls out. Should the frontal boundary stall out
further north, then the chances for rain will decrease for Monday
afternoon. Further updates on this developing situation are expected.

The frontal boundary is expected to finally move through the region
late Tuesday into Wednesday. At this point, the temperatures are not
expected to change much with this frontal passage, but the winds are
expected to shift towards the north after the frontal passage. Most
of next week generally has low rain chances (less than 30%). Most
showers and thunderstorms will be related to any sort of seabreeze
activity. There is some model guidance that suggests that another
front may try to move through the region late next week, however
further forecast shifts will need to continue to monitor the model
trends to see how the forecast continues to evolve.

&&

.AVIATION...
(18Z TAFS)
Issued at 1216 PM CDT Sat Aug 30 2025

VFR conditions are expected to persist through the TAF cycle at
all TAF sites. Southerly to southeasterly winds are expected to
persist with some low-level clouds in the region.

&&

.MARINE...
Issued at 1216 PM CDT Sat Aug 30 2025

Generally favorable conditions with mostly light to moderate
southerly to southeasterly winds and low to moderate seas. Medium
chances (40-60%) of rain are expected for Monday afternoon as a
frontal boundary stalls out towards the north. By late Tuesday into
Wednesday, the front is expected to push through in the Lower Texas
Coast and the winds are expected to turn to towards the north while
remaining light to moderate. The winds should return to the south
fairly quickly.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             80  96  79  96 /   0  10  10  40
HARLINGEN               76  98  75  97 /   0  10  10  40
MCALLEN                 79 102  79 101 /   0  10   0  40
RIO GRANDE CITY         77 104  77 102 /   0   0   0  30
SOUTH PADRE ISLAND      83  90  82  89 /   0   0  10  30
BAYVIEW/PORT ISABEL     79  93  78  93 /   0  10  10  30

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&

$$

SHORT TERM...64-Katz
LONG TERM....64-Katz
AVIATION...64-Katz