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513
FXUS64 KBRO 240543 AAB
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1243 AM CDT Fri May 24 2024

...New AVIATION...

.SHORT TERM...
(Tonight through Friday night)
Issued at 303 PM CDT Thu May 23 2024

Heat will continue to be the primary concern during the short term
period.  An upper level ridge over Northern Mexico and South Texas
will support broad subsidence across the region, limiting cloud
cover during the afternoon. South easterly surface winds will
continue to advect warm, humid air into Deep South Texas, which will
support the development of low clouds overnight, as well as increase
temperatures and dewpoints. The combination of these factors will
lead to higher apparent temperatures overnight and during the day
Friday. Apparent temperatures are expected to remain in the upper
80s to low 90s tonight, and exceed 115 for much of the area Friday
afternoon. The heat advisory this afternoon has been extended
through the night, and will be replaced with an Excessive Heat
Warning Friday morning.

Additionally, moderate winds and seas will create a moderate risk of
rip currents through the period at area beaches.

&&

.LONG TERM...
(Saturday through next Thursday)
Issued at 303 PM CDT Thu May 23 2024

Key Messages:

- Dangerous heat will continue through at least Tuesday, including
  Memorial Day Weekend.

- There will be an extreme risk of heat-related impacts,
  especially for those that do not stay hydrated or take frequent
  breaks in the shade/indoors.

- Moderate to high risk of rip currents will exist this holiday
  weekend.

Deep South Texas will remain under the influence of mid/upper
level ridging through early next week. Guidance continues to
indicate 850mb temperatures well above normal, ranging from
27-31C, which will allow for the already oppressive heat we`ve
experienced this week to further intensify. Triple-digit high
temperatures are forecast for most of Deep South Texas Saturday
through Tuesday, with the exception being along the Lower Texas
beaches and the immediate coast. High temperatures will be
greatest over the Rio Grande Plains, with highs reaching anywhere
from 107-110 degrees each afternoon. Despite high temperatures
closer to 100-105 degrees for the Rio Grande Valley and portions
of the Brush Country, the combination of hot temperatures and high
dew points will result in heat indices in the 113 to 120 degree
range. In addition, daily record high temperatures will likely be
tied or broken at Brownsville, McAllen, and Harlingen airports.

If the oppressive daytime heat was not enough, there really won`t
be much relief overnight as low temperatures only fall to around
79 degrees over the Northern Ranchlands and low 80s across the Rio
Grande Valley. In combination with the high dew points, especially
closer to the coast, heat indices at the start of the day will be
in the upper 80s and low 90s. Similar to record high temperatures,
daily record highest low temperatures will also be tied or broken.

This type of extreme heat will be very dangerous for anyone
spending time outside this weekend. Taking the necessary
precautions will be vital to reduce the risk of heat-related
illnesses. It is highly recommended to drink plenty of water,
even if you do not feel thirsty, take frequent breaks in the shade
or indoors, and wear light-colored, loose-fitting clothing.

There may be some relief from the heat by mid week as a weak cold
front approaches from Central Texas. This may bring some very
limited rain chances, and perhaps some increased cloud cover to
portions of Deep South Texas which will allow for slightly lower
afternoon temperatures.

&&

.AVIATION...
-- Changed Discussion --
(06Z TAFS)
Issued at 1227 AM CDT Fri May 24 2024

MVFR covers all of the Rio Grande Valley and the three regional
airports through mid-morning Friday with VFR developing for Friday
afternoon through at least sunset. Gusty periods of south winds
with gusts 18-23 knots overnight become fore frequent and stronger
Friday afternoon with the gusts approaching 30 knots at times.
The temperatures Friday through the holiday weekend will be
increasing with heat index values over 110 degrees each
afternoon. This is likely to lower the Density Altitude.
-- End Changed Discussion --


&&

.MARINE...
Issued at 303 PM CDT Thu May 23 2024

This afternoon through Friday night...High pressure over the
Eastern Gulf and low pressure over Central Mexico will support
higher winds and seas this afternoon. A Small Craft Advisory is in
effect until 7pm this evening. Winds are expected to decrease
slightly tonight, however Small Craft Exercise Caution headlines
will likely be needed through the period.

Saturday through next Thursday...An enhanced pressure gradient
will result in moderate to breezy winds and moderate seas this
weekend. Small Craft Exercise Caution will likely continue through
the weekend, before becoming more favorable early next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
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BROWNSVILLE             81 101  83 100 /   0   0   0   0
HARLINGEN               79 100  80 102 /   0   0   0   0
MCALLEN                 80 102  82 106 /   0   0   0   0
RIO GRANDE CITY         79 106  81 108 /   0   0   0   0
SOUTH PADRE ISLAND      82  91  83  90 /   0   0   0   0
BAYVIEW/PORT ISABEL     79  95  81  96 /   0   0   0   0
-- End Changed Discussion --

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
TX...Heat Advisory until 10 AM CDT this morning for TXZ248>253-353.

     Excessive Heat Warning from 10 AM this morning to 7 PM CDT this
     evening for TXZ248>253-353.

     Heat Advisory until 7 PM CDT this evening for TXZ254-255-351-354-
     355.

GM...None.
-- End Changed Discussion --
&&

$$

SHORT TERM...60
LONG TERM....22
AVIATION...59-GB