338
FXUS64 KBRO 180543 AAB
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1243 AM CDT Tue Mar 18 2025

...New AVIATION...

.SHORT TERM...
(Tonight through Tuesday night)
Issued at 225 PM CDT Mon Mar 17 2025

We expect warm and dry weather to continue through the short term
period. Upper-level ridging shifting eastward from the Central US
to the East Coast looks to support a surface high over the
Southeastern US and Central Gulf. A the same time, an upper level
trough crossing the front range of the Rockies looks to support
the development of a surface low over the High Plains Tuesday
morning. The interaction of these pressure systems will tighten
pressure gradients along the Texas Coast extending into the
Midwest. A 30 kt LLJ looks to develop along the Texas Coast
Tuesday morning, with stronger winds mixing down to the surface
through Tuesday evening.

Wind gusts will likely exceed Wind Advisory criteria for Southern
Hidalgo County, Cameron County, and much of Willacy County
Tuesday afternoon. A Wind Advisory has been issued for Southern
Hidalgo, Inland Willacy, and Inland and Coastal Cameron Counties
from noon Tuesday until 7 PM Tuesday evening.

Additionally, the stronger winds combined with low afternoon RH
values and dry fuels will support enhanced fire weather concerns
through the afternoon across Deep South Texas. A Red Flag Warning
for the eastern half of the CWA, except for the immediate coast
and barrier islands, will go into effect at noon Tuesday and
continue through 8 PM. The western half of the CWA will likely see
slightly lower wind speeds, however a Fire Danger Statement will
be needed for those counties Tuesday afternoon. See the Fire
Weather section for more info.

Finally, stronger winds offshore will support building seas
tonight and Tuesday, resulting in a Moderate Risk for Rip Currents
tonight, and a High Risk of Rip Currents Tuesday.

&&

.LONG TERM...
(Wednesday through next Monday)
Issued at 225 PM CDT Mon Mar 17 2025

Key message:

*  There will be an elevated fire weather threat Wednesday in the
   wake of a cold front (see the Fire Weather section below).

Summary: Loaded the NBM without significant adjustment. A dry cold
front will arrive Wednesday morning, prolonging fire weather
concerns but also ushering in a couple of days (Thursday and
Friday) of milder weather with temps nearer normal. Temperatures
will trend higher again this weekend, with the next cold front
slated for next Monday morning.

A Plains storm system will move rapidly east over the Central Plains
Tuesday into Wednesday, with a front reaching the CWA Wednesday
morning. We don`t expect much (if any) rain with the front, but a
few coastal showers could develop as the front moves offshore.
High temps will be in the mid to upper 80s. Dry, desert high
pressure and H5 ridging building in behind the front will do
little to nothing to ease the current drought and elevated fire
weather threat.

However, temperatures will cool for Thursday morning through Friday
while high pressure spreads over the area. Lows will be in the 50s
and 60s. Thursday high temps will be a skosh (2 to 3 degrees) lower
than normal (upper 70s) and Friday high temps will be a skosh above
normal (lower to mid 80s), with normal being around 80. Temps will
trend higher this weekend, with low temps in the 60s and high temps
in the upper 80s to lower 90s.

Breezy onshore winds will develop again on Friday as the pressure
gradient tightens in response to another weather system tracking
through the Plains. A third, somewhat deeper storm system moving
into the Northern Plains with an H5 ridge building over the West
will support a cold front pushing through the Southern High Plains
into Texas on Sunday. This front should reach the Gulf of America
Monday morning, with a few showers showing up over the Lower RGV
Monday morning.

&&

.AVIATION...
(06Z TAFS)
Issued at 1237 AM CDT Tue Mar 18 2025

Mostly clear skies and light to moderate southeast winds prevail
across Deep South Texas early this morning. VFR conditions will
continue for the next 24 hours. Winds will remain moderate to
occasionally gusty overnight. Today will be a very windy with
southeasterly winds increasing after daybreak. Strong winds of 25
to 30 kts are likely by the afternoon, with gusts to or exceeding
35 kts, especially at BRO and HRL.

&&

.MARINE...
Issued at 225 PM CDT Mon Mar 17 2025

Tonight through Tuesday night...Pressure gradients along the
Lower Texas Coast look to tighten tonight and through Tuesday
night, thanks to the interaction of a strengthening surface high
pressure system over the Central Gulf and a developing surface low
pressure system over the High Plains. Additionally, tightening of
the pressure gradients is possible Tuesday afternoon and evening,
ahead of a cold front associated with the aforementioned surface
low. Wind speeds will increase in response to the pressure
gradient, resulting in building seas through the period. Small
Craft Should Exercise Caution headlines will likely be needed for
the coastal waters tonight, and a Small Craft Advisory will
likely be needed Tuesday and Tuesday night.

Wednesday through Saturday night...

Key message:

*   Enhanced marine winds and seas in the wake of a Wednesday cold
    front will prolong less than optimal marine conditions through
    Thursday.

Fresh to strong north to northeast marine winds will develop on
Wednesday in the wake of a cold front, rebuilding seas. The result
will be low end small craft advisory conditions Wednesday through
Thursday. Thursday night through Saturday night will be a recovery
period with weaker winds and lower seas.|

&&

.FIRE WEATHER...
Issued at 225 PM CDT Mon Mar 17 2025

Tuesday: The Fire Weather Watch Tuesday has been upgraded to a
Red Flag Warning for Hidalgo, Brooks, Inland Kenedy, Inland
Willacy, and Inland Cameron counties from noon Tuesday until 8 PM
Tuesday evening.

Relative humidity values look to recover to around 80% tonight
across the area. Sustained southeasterly winds will continue to
advect some additional moisture to the area. This will keep minimum
relative humidity values slightly higher Tuesday afternoon than they
were today, around 20-30% across Zapata, Jim Hogg and Starr
Counties, and 30-45% across the eastern half of the CWA, excluding
the immediate coast and barrier islands. However, tightening
pressure gradients along the Texas Coast look to support higher wind
speeds Tuesday, with 20 ft winds reaching at least 25 mph across the
eastern half of the CWA. Wind speeds across the western half of the
CWA looks to remain slightly lower, topping out around 20 mph
Tuesday afternoon.

In spite of the higher humidity values Tuesday, these higher wind
speeds will lead to increased fire weather conditions Tuesday,
requiring a Red Flag Warning for Hidalgo, Brooks, Inland Kenedy,
Inland Willacy, and Inland Cameron counties Tuesday afternoon.
Zapata, Jim Hogg, and Star counties are more borderline, with
conditions favoring a Fire Danger Statement Tuesday, however if wind
speeds increase for these counties, the Red Flag Warning may need to
be extended westward.

Key message:

*   We expect an enhanced fire weather threat on Wednesday.

Wednesday: A dry cold front will move through the CWA Wednesday
morning, bringing breezy northwest winds and lower relative
humidity air. Along with critically dry to extremely dry surface
fuels, the situation will support a high potential for wildfire
activity. The fire weather threat will be greatest for the Brush
Country and Upper Valley, essentially everything west of the I-69C
corridor. We have medium to high confidence that conditions will
meet Rangeland Fire Danger (RFD) criteria from late Wednesday
morning through mid- Wednesday afternoon due to dry fuels, low
relative humidity values, and post-frontal 15 to 20 mph 20 ft
winds.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             67  86  58  72 /   0   0   0   0
HARLINGEN               64  89  53  75 /   0   0   0   0
MCALLEN                 66  91  55  80 /   0   0   0   0
RIO GRANDE CITY         62  87  53  78 /   0   0   0   0
SOUTH PADRE ISLAND      66  76  61  67 /   0   0   0   0
BAYVIEW/PORT ISABEL     65  82  58  70 /   0   0   0   0

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Red Flag Warning from noon today to 8 PM CDT this evening for
     TXZ250-251-253>255-353.

     Wind Advisory from noon today to 7 PM CDT this evening for
     TXZ253>255-355.

     High Rip Current Risk from 7 AM CDT this morning through this
     evening for TXZ451-454-455.

GM...Small Craft Advisory from 4 AM early this morning to 7 AM CDT
     Wednesday for GMZ130-132-135-150-155-170-175.

&&

$$

SHORT TERM...60-BE
LONG TERM....54-BHM
AVIATION...63-KC