366
FXUS64 KBRO 182327 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
627 PM CDT Wed Sep 18 2024

...New AVIATION...

.SHORT TERM...
(Tonight through Thursday night)
Issued at 227 PM CDT Wed Sep 18 2024

Mid-level ridging will hold steady over the area during the short
term. Weak high pressure will also dominate across the Northwest
Gulf leading to light to moderate onshore winds. The Gulf may see
fairly steady isolated showers through the period, with any action
over the CWA focused more on a daily afternoon sea breeze.

Convection overall should not be particularly strong, and the CWA is
not currently in any thunderstorm outlook area, but moisture is
elevated (above 2 inches PWAT at KBRO this morning), and any showers
could be efficient rain makers. We are not currently in an excessive
rainfall outlook category, however.

As well, the enhanced moisture, combining with high temperatures a
few degrees above normal, mainly in the mid 90s, will produce heat
index values of 105 to 110 for the coastal and mid Valley sections
of the CWA. Heat advisory conditions will be very marginal, however,
and an special weather statement (SPS) may be sufficient for the
Thursday aftn heat. Finally, rip current risk is currently moderate
as we work through a full moon phase.

&&

.LONG TERM...
(Friday through next Wednesday)
Issued at 227 PM CDT Wed Sep 18 2024

Midlevel high pressure over Deep South Texas will begin to slide
eastward next week as a low over the four corners lifts into the
upper midwest. At the surface, high pressure over the northern
Gulf into the SE United States lifts into the Mid-Atlantic early
next week, creating a general weakness across the western Gulf.

East to southeasterly flow will continue to keep the atmosphere
somewhat moisture laden. PWATs are forecasted to remain generally
between 1.75 and 2 inches through the period, which is still
above normal. While subsidence should keep most areas rain free
through the longterm, we will continue to see isolated chances of
showers and thunderstorms each day, becoming a bit more active by
midweek, mainly along the sea breeze. Brief periods of heavy
rainfall with this activity will be possible.

Temperatures throughout the period will remain near normal with
highs in the low to mid 90s. Any rain or thunderstorm activity
early in the afternoon, especially as we head into the middle of
next week, could keep temperatures just below normal for affected
areas. Overnight lows will remain generally in the low to mid
70s. While Heat Advisories are not likely Saturday through
Wednesday, Friday afternoon some areas (mainly Hidalgo county)
could see heat indices reach 111 or 112 degrees for an hour or
two. Will continue to monitor for the possibility of a Heat
Advisory being needed, but at this time a Special Weather
Statement may suffice.

The National Hurricane Center is monitoring an area for potential
tropical development in the Northwestern Carribean Sea. Current
projected movement is north or northwest over the northwestern
Carribean or southern Gulf with a 20% chance of tropical development
(low) in the next 7 days. The development (or lack there) of and
movement of this entity will be a factor in the forecast late in
the period and beyond with changes to the forecast possible.

&&

.AVIATION...
(00Z TAFS)
Issued at 619 PM CDT Wed Sep 18 2024

VFR conditions are expected to continue through the TAF period.
Some isolated showers and thunderstorms may develop Thursday
afternoon, which could briefly drop ceilings and visibility to
MVFR levels if any convection moves over an airfield. However,
confidence in any site experiencing impacts is too low to include
in the TAFs at this time.

&&

.MARINE...
Issued at 227 PM CDT Wed Sep 18 2024

Tonight through Thursday night...We are forecasting light southeast
winds and low seas for the short term. Isolated showers and
thunderstorms may pop up from time to time and could result in heavy
rainfall, gusty winds and chaotic seas.

Friday through Tuesday...Light to moderate winds and light seas are
expected the period with seas of 1 to 3 feet. There is a slight
chance of showers and thunderstorms daily, which may result in brief
periods of elevated winds and seas.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             79  92  79  91 /  10  20  10  40
HARLINGEN               77  94  76  93 /   0  30  10  30
MCALLEN                 79  98  80  96 /   0  20  10  30
RIO GRANDE CITY         77  96  78  95 /  10  10  10  20
SOUTH PADRE ISLAND      82  88  82  88 /  10  20  20  30
BAYVIEW/PORT ISABEL     78  91  78  90 /  10  20  10  30

&&

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

$$

SHORT TERM...54
LONG TERM....68
AVIATION...60-BE