Sharyland, Texas Weather Forecast Discussion

558
FXUS64 KBRO 090546 AAA
AFDBRO
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1246 AM CDT Tue Sep 9 2025
...New AVIATION...
.DISCUSSION...
Issued at 1030 PM CDT Mon Sep 8 2025
A combination of daily seabreeze boundaries, diurnal instability and
slight divergence aloft is expected to continue to result in daily
chances of showers and thunderstorms across deep south Texas
throughout the rest of this week and into the beginning of next,
maximizing during the afternoon and minimizing overnight. Today,
there is a medium to likely (40% to 70%) chance of rain for the
coastal counties, eastern and southern portions of the northern
ranchlands as well as the mid Rio Grande Valley, with the greatest
chances across the lower Rio Grande Valley along and east of I-69 E,
where lingering surface convergence and elevated PWAT values reside
in association with a weak frontal boundary stalled near the
southern border. Meanwhile, PoP`s across the Rio Grande Plains and
western portions of the northern ranchlands range from less than 15%
to 30%, due to increased subsidence aloft from an expanding area of
mid-level ridging, centered over western Texas. Tomorrow and onward,
probabilities of rain become more widespread across the region as
the frontal boundary mixes out, leaving easterly onshore winds
leading to diurally-driven convection along the seabreeze boundary.
As the mid-level high pressure slowly moves north of the CWA
throughout the remainder of the work week and expands further over
the Mississippi River Valley over the weekend, chances of rain
decrease from a medium to likely (40-70%) tomorrow through Friday to
mostly a low to medium (30% to 40%) chance over the weekend, with
elevated chances again next week as subsidence decreases aloft.
Daily probabilities are highest along and east of US-281/I-69 C
during the afternoon, where lightning, heavy rain and gusty winds
are possible within the deepest and strongest of convection.
Increased cloud coverage each day is likely to keep temperatures
average for this time of year with high temperatures near and along
the coast in the mid 80`s and nearly all of inland deep south Texas
in the 90`s, ranging from the mid/upper 90`s across the Rio Grande
Plains to low/mid 90`s elsewhere. Despite enhanced moisture from
rain, afternoon heat indices of generally 100-107 degF, limited to
the Rio Grande Valley and the coastal counties, is expected to
result in mostly a minor heat risk across the CWA. Portions of the
coastal counties are likely to experience minor to moderate heat
risks due heightened humidity brought inland via light onshore
flow.
&&
.AVIATION...
(06Z TAFS)
Issued at 1241 AM CDT Tue Sep 9 2025
VFR will prevail at the aerodromes through the next 24 hours. A
TEMPO has been included, based on HRRR model guidance, for the
possibility of daytime convection on Tuesday. Light to moderate
winds are also anticipated.
&&
.MARINE...
Issued at 1030 PM CDT Mon Sep 8 2025
Favorable marine conditions continue as mainly gentle to moderate
easterly winds and slight to moderate seas prevail along with medium
to likely chances of showers and thunderstorms.
&&
.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             91  78  92  78 /  70  60  70  60
HARLINGEN               91  73  93  74 /  60  30  60  30
MCALLEN                 94  77  95  77 /  50  20  60  30
RIO GRANDE CITY         95  74  96  74 /  30   0  50  20
SOUTH PADRE ISLAND      87  80  87  81 /  80  60  70  70
BAYVIEW/PORT ISABEL     89  77  90  78 /  70  50  70  50
&&
.BRO WATCHES/WARNINGS/ADVISORIES...None.
&&
$$

NWS BRO Office Area Forecast Discussion