351
FXUS64 KBRO 311132 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
632 AM CDT Fri May 31 2024

...New AVIATION...

.SHORT TERM...
(Today through Saturday)
Issued at 307 AM CDT Fri May 31 2024

An upper-level ridge centered over Northern Mexico looks to
remain in place through the short term period. A shortwave moving
through the northern periphery of the ridge will likely enhance
forcing over eastern Texas this evening. Most guidance has the
bulk of the forcing staying north of the BRO CWA, however the
ECMWF continues to track the shortwave a bit further south,
clipping the Northwestern portion of the CWA. Good surface
moisture and plenty of CAPE could support the development of
isolated showers and thunderstorms if given sufficient forcing to
overcome the modest CAP. For this reason, PoPs have been left at
15- 20% for portions of Zapata and Jim Hogg Counties this evening.
Additionally, there is a chance for some isolated showers and
thunderstorms tonight over the northern portions of the coastal
Gulf waters. Otherwise, rain chances are expected to remain near
zero through the period.

Heat remains the primary concern through the period, with heat
indices expected to reach 112 degrees for portions of Deep South
Texas this afternoon. A Heat Advisory is in effect today from 1 PM
to 7 PM for Starr, Hidalgo, Brooks, Inland Willacy, and Inland
Kenedy Counties. Heat indices are expected to top out between 105-
110 degrees for the remainder of Deep South Texas.

A similar story looks likely Saturday, with heat indices topping out
around 11-112 degrees again Saturday afternoon. This will likely
require an additional heat advisory for Saturday.

Lastly, moderate to fresh southeasterly winds along the coast are
expected to build higher seas and increase Rip Current Risk through
the period. A High Risk for rip currents are expected tonight and
Saturday for area beaches.

&&

.LONG TERM...
(Saturday Night through Thursday)
Issued at 307 AM CDT Fri May 31 2024

500 mb high pressure initially centered over Mexico will gradually
build north through the period, eventually becoming centered over
west Texas. This will produce dry weather across the BRO CWFA,
with not even the risk for convection off of the higher terrain of
neighboring Mexico.

Meanwhile, a steady increase in daytime high temperatures is also
anticipated. Although the combination of ambient air temperatures
and relative humidity percentages will only support a SPECIAL
WEATHER STATEMENT on Sunday, a HEAT ADVISORY is likely to be
needed for portions or all of Deep South Texas and the Rio Grande
Valley Monday through Thursday, with areal coverage of the HEAT
ADVISORY likely to increase each day.

Finally, the interaction between thermal low pressure over Mexico
and high pressure over the Gulf of Mexico will create a windy
onshore flow through the period. The gradient may be intense
enough such that a WIND ADVISORY may be needed over the immediate
coastal counties (Cameron, Willacy, Kenedy) Sunday and maybe also
on Monday.

&&

.AVIATION...
(12Z TAFS)
Issued at 631 AM CDT Fri May 31 2024

MVFR ceilings and some slight visibility reductions are being
observed at all three TAF sites this morning. Both the visibility
and ceilings are expected to improve after sunrise, with VFR
conditions returning later this morning. MVFR ceilings are
expected to redevlop tonight and continue through the end of the
TAF period.

Gusty southeasterly winds are expected to continue through the
period.

&&

.MARINE...
(Today through Saturday)
Issued at 307 AM CDT Fri May 31 2024

Broad surface high pressure across the Northern Gulf and a
strengthening surface low over Central Mexico will enhance
pressure gradients along the Southern Texas Coast through the
short term period. This will support moderate to fresh
southeasterly winds and moderate seas through the period. A Small
Craft Advisory is in effect until 1 PM this afternoon for the
Laguna Madre and coastal Gulf waters. Small Craft Should Exercise
Caution headlines will likely be needed through the remainder of
the short term period, as winds and seas are expected to remain
just below Small Craft Advisory thresholds.

(Saturday Night through Thursday)
Small Craft Advisory conditions will exist along the Lower Texas
Coast through a majority of the period courtesy of thermal low
pressure over Mexico interacting with high pressure over the Gulf
of Mexico. Marine conditions may improve to Small Craft Exercise
Caution criteria Wednesday night through Thursday as high pressure
builds farther west into the western Gulf of Mexico.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             95  83  96  82 /   0   0   0   0
HARLINGEN               97  79  98  80 /   0  10   0  10
MCALLEN                 99  81 100  81 /   0  10   0  10
RIO GRANDE CITY        100  80 101  80 /  10  10   0  10
SOUTH PADRE ISLAND      88  83  88  83 /   0  10   0  10
BAYVIEW/PORT ISABEL     93  81  93  81 /  10  10   0  10

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Heat Advisory from 1 PM this afternoon to 7 PM CDT this evening
     for TXZ250>254-353.

     High Rip Current Risk from this evening through Saturday evening
     for TXZ451-454-455.

GM...Small Craft Advisory until 1 PM CDT this afternoon for GMZ130-
     132-135-150-155-170-175.

&&

$$

SHORT TERM...60-BE
LONG TERM....66-Tomaselli
AVIATION...60-BE