360
FXUS64 KBRO 291917
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
217 PM CDT Wed May 29 2024

...New SHORT TERM, LONG TERM, MARINE...

.SHORT TERM...
(This Afternoon through Thursday night)
Issued at 217 PM CDT Wed May 29 2024

A generally pleasant afternoon is shaping up across Deep South
Texas in wake of last night`s showers and thunderstorms. Most
areas are observing temperatures in the upper 80s and low 90s,
with dew points running around 3-10 degrees lower than the past
few days. While still mildly warm with heat indices in the mid
90s to around 100 degrees, it`s not quite the intense heat we`ve
had the last week or so. In addition to the lower temperatures,
last night`s convection also scoured out the haze aloft, allowing
for fair to moderate air quality today.

This will be short lived, however, as winds gradually return to
the southeast and allow for a steady increase in humidity once
again. Low clouds will develop late this evening from east to west
as low level flow transports Gulf moisture overhead. This will
also result in the return of mild low temperatures, ranging from
the mid 70s across the Northern Ranchlands to around or just below
80 degrees closer to the coast. There are low rain chances (20% or
less) mainly across the Northern Ranchlands tonight. Overall, not
expecting much in terms of coverage, but an isolated shower/storm
cannot be ruled out.

Thursday will be another seasonably warm and breezy day as Deep
South Texas remains along the northeastern periphery of the
mid/upper level ridge over Mexico. Highs will range from the mid
to upper 90s for most of the region, with a few areas reaching 100
degrees across the Upper RGV and Rio Grande Plains. Heat indices
will be slightly higher tomorrow afternoon, with a few areas
reaching 111 degrees. A Heat Advisory may be needed, but heat
indices will likely remain just below criteria. South to southeast
winds around 10 to 15 MPH with gusts around 20-25 MPH are expected
by mid morning to early afternoon, with the highest winds/wind
gusts along the immediate coast. Have maintained a rain-free
forecast for Thursday and Thursday night, but we`ll have to keep
an eye on the influence of embedded disturbances within
northwesterly flow aloft which could result in thunderstorms
developing to our north and west. Otherwise, another mild and
cloud night is expected tomorrow night with lows ranging from the
upper 70s to low 80s.

&&

.LONG TERM...
(Friday through next Wednesday)
Issued at 217 PM CDT Wed May 29 2024

Key Messages:

*Above normal high and low temperatures

*Best chance for rain on Saturday

The above normal temperature will continue through the long term
forecast period. The mid-level ridge looks to continue to dominate
the weather patterns for Deep South Texas and the Rio Grande Valley.
As such the high temperatures are going to be in the range of upper
90s along the coast and the barrier island to the triple digits for
the rest of the region. With surface winds staying out of the
southeast for the long term forecast period, this will transport more
humid hot air into the area. As such, the heat indices for the long
term forecast period are expected to be in the range of 105 to 114.
However, the need for Heat Advisories seems to have trended down
just a bit with this latest model analysis. The higher heat indices
do not seem to last long enough to warrant a Heat Advisory for
Friday through Tuesday at this point. However, an SPS for the high
heat indices will still be needed. While the experimental HeatRisk
tool does show plenty of major heat risk for those days, there are
only a smaller region of extreme on those days. However, by Tuesday,
the HeatRisk tool has a large area of extreme. Currently, Wednesday,
seems to have the largest chance for needing a Heat Advisory.
Further forecast shifts will need to continue to monitor this.

Finally, the rain chances still look to be very low for most of the
long term forecast period. As the middle and upper levels of the
atmosphere are still pretty dry. However, by Saturday, the middle
levels of the atmosphere will start to become a bit more moist, and
a shortwave could help some showers and thunderstorms fire up along
the Sierra Madre and move into the region. A tightening pressure is
expected for the weekend and Monday that will enhance the winds in
the region, but seems to be not as strong as before to require a
Wind Advisory.

&&

.AVIATION...
(18Z TAFS)
Issued at 1227 PM CDT Wed May 29 2024

VFR to MVFR conditions across the region with generally light
winds in wake of last night`s convection. Expect light and
variable winds to gradually return to the southeast around 5-10
knots through the afternoon hours and persist through the TAF
period. Stratus clouds will develop after 02-03Z at BRO and HRL,
and closer to 04Z at MFE. VFR should return by 13-15Z Thursday.

&&

.MARINE...
Issued at 217 PM CDT Wed May 29 2024

Tonight through Thursday night...Generally favorable marine
conditions will prevail tonight. Increasing winds in response to
an enhanced pressure gradient will result in Small Craft Exercise
Caution conditions along the Laguna Madre and nearshore Gulf
waters Thursday afternoon and evening. Low rain chances exist
tomorrow.

Friday through next Wednesday...Moderate southeast winds and
moderate seas thanks to a locally enhanced pressure gradient will
generate adverse conditions that will mostly likely require Small
Craft Exercise Caution through next Wednesday. A low-end Small Craft
Advisory cannot be ruled out either.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             81  94  82  95 /  10  10  10   0
HARLINGEN               78  96  80  97 /  10  10  10   0
MCALLEN                 80  99  81  99 /  10   0  10   0
RIO GRANDE CITY         79 100  79 101 /  10  10  10  10
SOUTH PADRE ISLAND      81  86  82  88 /  10  10  10   0
BAYVIEW/PORT ISABEL     80  92  81  93 /  10  10  10   0

&&

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

$$

SHORT TERM...22-Garcia
LONG TERM....64-Katz
AVIATION...22-Garcia