938
FXUS64 KBRO 171128 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
628 AM CDT Sat May 17 2025

...New AVIATION...

.SHORT TERM...
(Today through Sunday)
Issued at 307 AM CDT Sat May 17 2025

Today through Sunday...The main concern in the short term will
continue to be the oppressive daytime heat. The 500mb subtropical
ridge centered over the Gulf will continue to bring mainly dry and
hot summer-like conditions over Deep South Texas through the
weekend. The combination of the unseasonable hot temperatures and
higher humidity will support heat indices between 105 to 110 degrees
across most of Deep South Texas this afternoon, which is just below
Heat Advisory criteria. The NBM continues to overforecast
temperatures and dewpoints in this current weather pattern.
Therefore, will lend towards a 50/50 or 1/3 CONSShort/NBM blend for
dewpoints and temperatures which is closer the observed observations
from the past few days. In addition, The HREF probability of
apparent temperatures reaching 111 degrees or higher, was less than
10 percent for this afternoon.  A majority of the Deep South Texas
is under a Major Risk (level 3 of 4) of heat-related illness for
today and Sunday. Isolated areas of Extreme (level 4 of 4) Heat Risk
will be possible this afternoon across portions of the northern
ranchlands. An slightly enhance pressure gradient will lead to
moderate to breezy southeast winds through the period.

The latest CAM models indicate some convection may develop across
the Sierra Madre later this afternoon and move towards Rio Grande
Plains this evening. Confidence remains low that the showers and
thunderstorms will hold together, especially in a highly capped
environment. However, decided to bump up pops across the western
portions of the CWA to around 10 percent.

There is a Moderate Risk of rip currents at local beaches today
through Sunday.

&&

.LONG TERM...
(Sunday night through Friday)
Issued at 307 AM CDT Sat May 17 2025

The subtropical ridge holds a dry and hot summer-like pattern
across Deep South Texas into mid-week. Persistent low pressure
across the Plains with a surface ridge anchored across the eastern
Gulf will maintain an enhanced pressure gradient locally and
increase humidity into Tuesday. A cold front drops south on
Wednesday, before stalling potentially near the border. Guidance
has developed a surface low along the border Wednesday afternoon
and evening near the boundary, which has increased POPs along the
border through Wednesday night. Otherwise, expect less heat and
less wind mid to late week.

Heat Advisories will likely be needed Monday and Tuesday. An
Excessive Heat Warning is not completely out of the question for
Tuesday afternoon, although the NBM has been overcooking Heat
Indices a bit through this event. Heat Risk levels are generally
Major (level 3 of 4) across inland portions of Deep South Texas on
Monday and Tuesday. Record highest low temperatures may become
threatened Monday and Tuesday mornings, with McAllen currently
forecast to reach a record high Tuesday afternoon.

&&

.AVIATION...
(12Z TAFS)
Issued at 626 AM CDT Sat May 17 2025

MVFR ceilings and light to moderate southeast winds prevail
across Deep South Texas early this morning. VFR conditions are
expected to return mid to late morning as southeast winds increase
to 15 to 20 knots. Some gusts around 25 knots will be possible
later this morning into the afternoon. Winds will gradually decrease
by late evening as MVFR ceilings return.

&&

.MARINE...
Issued at 307 AM CDT Sat May 17 2025

Today through Sunday...A slightly enhanced pressure gradient will
continue to produce moderate winds and seas through the weekend.
Small Craft Exercise Caution conditions are expected on the Laguna
Madre and the Gulf waters today into Sunday due to elevated winds
and/or seas.

Sunday Night through Friday...Moderate southeasterly winds
generally continue into mid next week, with SCEC to borderline SCA
conditions every afternoon on the bay and nearshore waters. Marine
conditions gradually improve into late week.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             92  78  93  79 /   0   0   0   0
HARLINGEN               95  77  94  78 /   0   0   0   0
MCALLEN                 98  80  97  80 /   0   0   0   0
RIO GRANDE CITY         99  78  99  78 /   0  10   0   0
SOUTH PADRE ISLAND      85  78  84  79 /   0   0   0   0
BAYVIEW/PORT ISABEL     90  77  90  77 /   0   0   0   0

&&

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

$$

SHORT TERM...63-KC
LONG TERM....56-Hallman
AVIATION...63-KC