069
FXUS64 KBRO 240536 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1236 AM CDT Mon Aug 24 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1233 AM CDT Mon Aug 24 2026

- Very hot, record to near record-breaking temperatures and rain-
  free conditions are expected to persist through this week.

- Widespread Major (Level 3 of 4) with increasing areas of Extreme
  (Level 4 of 4) Heat Risk is expected through this week.

- Worsening drought conditions are expected to continue due to the
  combination of very hot temperatures, antecedent dry conditions,
  and very high evaporation rates.

- The combination of dry fuels, lowering relative humidity
  values, and hot temperatures could lead to elevated fire danger
  risks through this week.

&&

.DISCUSSION...
Issued at 1017 PM CDT Sun Aug 23 2026

An anomalously strong, sprawling 594-598 dam heat dome, that`s
resulting in a dangerous heat wave across the Southwest U.S. and
Southern Plains, will continue to yield hotter than normal, record
to near record-breaking temperatures over Deep South Texas and the
Rio Grande Valley through next weekend and for that matter through
the month of August (see CLIMATE SECTION). To put into context
how persistent the heat has been, Brownsville and Harlingen today
recorded its 6th and 7th consecutive 100F degree day,
respectively amid this strong and vast heat dome.

Widespread triple digit heating including over Harlingen and
Brownsville will continue through the forecast period as the
aforementioned heat dome remains parked over the 4-Corners Region.
Given the fact that climatologically we are in the hottest part
of the year (i.e. average high temperature for McAllen is 100F
degrees) and yet forecasted temperatures are projected to be 4-8F
degrees hotter than the climatological peak temperatures will
result in dangerously hot conditions even for the RGV`s standards
in the days ahead. That said, widespread Major (Level 3 of 4) with
increasing areas of Extreme (Level 4 of 4) Heat Risk is expected
through next weekend.

The combination of very hot temperatures and dry conditions will
continue to result in very strong evaporation rates. This will lead
to a continuation of worsening or expanding drought conditions
across Deep South Texas and Rio Grande Valley during this stretch.
Furthermore, wildfire concerns will also remain on the table through
next weekend as relative humidity (RH) levels drop during the
afternoon hours to near Fire Danger Statement (RFD) criteria on
already dry fuels. Winds and RH value trends will need to be
closely monitored through next weekend for the potential issuance
of a Fire Danger Statement.

&&

.AVIATION...
(06Z TAFS)
Issued at 1233 AM CDT Mon Aug 24 2026

VFR conditions are forecast to continue through the TAF period.
Light and variable winds overnight are forecast to increase out of
the southeast late Monday morning, with gusts increasing through
the afternoon.

&&

.MARINE...
Issued at 1017 PM CDT Sun Aug 23 2026

Favorable marine conditions are expected throughout the week with
low seas (1 to 2 foot wave heights) and light to moderate
southeasterly winds.

&&

.CLIMATE...
Issued at 1017 PM CDT Sun Aug 23 2026

A massive and strong 594-598 dam heat dome situated over the
Southwest U.S. and the Southern Plains will result in record to near
record-breaking temperatures during the workweek. Daytime high
temperature anomalies are expected to run 4-8F degrees above normal
levels during this timeframe.

Below is a list of record highs from August 24-28:

Monday August 24th, 2026

Brownsville: 100F in 1970
Harlingen: 102F in 2010, 1936, & 1952
McAllen: 105F in 2018

Tuesday August 25th, 2026

Brownsville: 100F in 2019
Harlingen: 103F in 1924
McAllen: 105F in 2019

Wednesday August 26th, 2026

Brownsville: 101F in 2019
Harlingen: 103F in 1924 and 1948
McAllen: 104F in 2019 and 2018

Thursday August 27th, 2026

Brownsville: 102F in 2023
Harlingen: 104F in 1948
McAllen: 105F in 2018

Friday August 28th, 2026

Brownsville: 106F in 2023
Harlingen: 106F in 2011
McAllen: 107F in 2023

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             98  80  98  81 /   0   0   0   0
HARLINGEN              102  76 102  77 /   0   0  10   0
MCALLEN                104  80 104  80 /   0   0   0   0
RIO GRANDE CITY        104  78 105  78 /   0   0   0   0
SOUTH PADRE ISLAND      89  81  90  81 /   0   0   0   0
BAYVIEW/PORT ISABEL     97  78  97  79 /   0   0   0   0

&&

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

$$

SHORT TERM...23
LONG TERM....23
AVIATION...60-BE