082
FXUS64 KBRO 300543 AAC
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1243 AM CDT Tue Apr 30 2024

...New AVIATION...

.UPDATE...
Issued at 958 PM CDT Mon Apr 29 2024

Pronounced outflow that tracked across the Lower Texas Gulf waters
earlier this evening...and was well defined on
satellite...continued to surge inland across the lower Valley
through Kenedy county between 8 and 9 pm..leaving a period of
gusty east winds up to 35 mph in its wake. A few sprinkles joined
the party as well...but no rain of significance. Updated the wind
forecast to account on land through midnight in these areas.

Similar conditions surged across the nearshore waters and Laguna
Madre where gusts to 30 knots likely kicked up a period of rough
waves in Laguna Madre. Farther offshore, when the boundary passed
Buoy 42002, winds briefly gusted to gale force and waves punched
up to 9 feet before recently subsiding. Small Craft Advisory
conditions are occurring/have occurred for a 2-3 hour period, but
given the convective and relatively short lived nature of the
event, decided to handle with a Marine Weather Statement for the
short fuse and Small Craft Exercise Caution for the updated
Coastal Waters Forecast.

Winds/waves should subside by midnight, with seas taking a little
longer to drop back over the Gulf. Thunderstorms along the Nuevo
Leon/Tamaulipas line, about 125 miles southwest of Brownsville as
of 10 PM...should remain well south of the border region while
dissipating overnight. That leaves the potential for a few light
showers on the residual easterly flow in the Gulf and perhaps into
Cameron/Willacy/Kenedy overnight...with little notable impact.

&&

.SHORT TERM...
(Tonight through Tuesday night)
Issued at 237 PM CDT Mon Apr 29 2024

Key Messages:

- There is a marginal risk for severe thunderstorms this afternoon
  and evening across the Northern Ranchlands.

- A high risk of rip currents along the Lower Texas beaches
  through Tuesday evening.

- Above normal temperatures continue across Deep South Texas.

The short term period will feature low precipitation chances,
partly to mostly cloudy skies, and above normal temperatures
across all of Deep South Texas. Persistent low level southerly to
southeasterly flow across the region has maintained warm and humid
conditions. The 12Z BRO sounding indicated precipitable water
values (PWATs) around 1.5 inches this morning, and GOES-16 Total
Precipitable Water satellite imagery measures PWATs ranging from
1.55 to 1.65 inches across Deep South Texas. Meanwhile, a weak
boundary north of the region will allow for isolated to scattered
showers and thunderstorms to develop late this afternoon and into
tonight.

High res guidance indicates the presence of steep mid-level lapse
rates, modest instability, and sufficient bulk shear values to
support the development of isolated severe thunderstorms with
primarily a hail and damaging wind gust threat, but lack of large
scale forcing will limit this potential. If any severe
thunderstorms were to develop, the best timing would be late this
afternoon and overnight, mainly over the Northern Ranchlands.
However, convective allowing models continue to indicate a mostly
rain/storm-free afternoon and overnight period, with mainly warm
air advection showers developing overnight across portions of Deep
South Texas and the Gulf waters. Isolated to scattered showers
may continue throughout the day on Tuesday, with the development
of isolated thunderstorms possible during the afternoon hours as
instability increases. Isolated thunderstorms may develop off of
the Sierra Madre, but should dissipate before reaching the region
late Tuesday afternoon/evening. Otherwise, a mild and overcast
night is expected tonight and Tuesday night with lows in the 70s.
Highs on Tuesday will range from the upper 70s along the Lower
Texas beaches to mid 90s across the Northern Ranchlands.

&&

.LONG TERM...
(Wednesday through next Monday)
Issued at 237 PM CDT Mon Apr 29 2024

Key Messages:

- Daily low (20-30%) precipitation chances for portions of Deep
  South Texas continue through the end of the week.

- Above normal temperatures persist through the weekend.

Breezy winds will return across Deep South Texas by the start of
the long term period as the pressure gradient tightens in response
to an upper level trough digging into the Rockies. Sustained winds
around 15-20 MPH with gusts up to 30 MPH are likely on Wednesday,
with similar wind speeds expected on Thursday as the trough and
attendant surface features track across the Northern Plains. As
low level southerly to southeasterly flow continues to transport
rich Gulf moisture northward and results in increasing PWATs, weak
disturbances embedded within westerly to southwesterly flow aloft
will result in daily low precipitation chances. The aforementioned
trough will send a cold front southward by the end of the week,
but model guidance continues to struggle with the timing of the
front and the southward extent before stalling.

Unfortunately, this will leave us with above normal temperatures
and humid conditions through the weekend with highs ranging from
the low 80s across the Lower Texas beaches to the mid 90s across
the Northern Ranchlands and lows in the 70s. With the steady
increase of low-level moisture and temperatures, we`ll have to
keep an eye on heat index values mid week. The latest guidance
indicates heat indices will approach 100-106 degrees across most
of the region, including the Mid/Upper Valley and the Northern
Ranchlands, Wednesday through Friday.

&&

.AVIATION...
(06Z TAFS)
Issued at 1233 AM CDT Tue Apr 30 2024

NWS Radar is showing scattered small light showers increasing
along and east-southeast of the lower Texas coast and NE Mexico.
These showers are steadily moving northwest with the general
southeast low level winds. Besides a passing shower overnight and
through Tuesday morning IFR to MVFR ceilings are expected. Models
suggest ceiling to rise to VFR by or shortly after 17-18Z. VFR
persist through the afternoon with the marine layer moving inland
shortly after sunset with ceilings lowering to MVFR and possibly
IFR before midnight. Light to moderate southeast winds persist
through the period with occasional gusts 18-22kts.


&&

.MARINE...
Issued at 237 PM CDT Mon Apr 29 2024

Tonight through Tuesday night...Light to moderate east to
southeast winds and moderate seas will prevail through the period.
Isolated to scattered showers and thunderstorms will be possible
tonight into Tuesday, which may result in higher winds and seas.

Wednesday through Sunday night...A tightening pressure gradient
will result in increased wind speeds on Wednesday, which may
approach Small Craft Exercise Caution to Small Craft Advisory
conditions beginning late Wednesday afternoon into Thursday. Wave
heights will respond and may reach 7-8 feet by Thursday.
Conditions should improve heading into the weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             77  88  77  90 /   0  10   0  10
HARLINGEN               74  91  75  92 /   0  10  10  10
MCALLEN                 77  92  77  93 /   0  10  10  10
RIO GRANDE CITY         75  93  76  95 /   0  10  10  10
SOUTH PADRE ISLAND      76  81  76  82 /  10  10  10   0
BAYVIEW/PORT ISABEL     74  87  75  88 /  10  10  10  10

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...High Rip Current Risk through this evening for TXZ451-454-455.

GM...None.
&&

$$

Update...52-Goldsmith
SHORT TERM...22-Garcia
LONG TERM....22-Garcia
AVIATION...59-GB