678
FXUS64 KBRO 091113 AAB
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
613 AM CDT Mon Mar 9 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 611 AM CDT Mon Mar 9 2026

Key Messages:

 - There is a low to medium (30-40%) chance of rain tonight
   along/west of US-281 and the Northern Ranchlands as isolated
   to scattered showers pass through as well as a low (15-20%)
   chance Tuesday night across the Northern Ranchlands and Rio
   Grande Plains.

 - Mainly dry and breezy conditions return Monday, becoming windy
   Tuesday, with a potential for a Wind Advisory as gusts up to
   40+ mph are possible along/east of US-281 by mid-morning
   Tuesday, continuing through the late afternoon hours. A Fire
   Danger Statement (RFD) is also possible on Tuesday.

 - Breezy to gusty conditions and much drier air behind a cold
   front on Wednesday are likely to result in elevated to
   critical fire weather conditions each afternoon, especially on
   Wednesday and Thursday, when Red Flag Warnings are possible.

 - Above average temperatures continue through the day Wednesday,
   briefly falling to near/below normal into the later parts of
   the week before rising back to above average next weekend.

 - A medium risk of rip currents continues through Monday
   afternoon, likely increasing to a High Risk of Rip Currents by
   the middle of the week as winds increase.

&&

.DISCUSSION...
Issued at 1040 PM CDT Sun Mar 8 2026

A stationary boundary remains situated along I-69 E this evening,
with southeasterly winds and warmer temperature to the east and
northeasterly to northwesterly winds and cooler temperatures to the
west. Convergence along this boundary resulted in area of
thunderstorms with heavy rain this afternoon, producing rainfall
amounts up to near 1.0-2.5 inches, extending southward from just
southeast of Raymondville to Harlingen. This frontal boundary is
expected to lift northward overnight as a tightening pressure
gradient enhances lower level south-southeasterly winds. Meanwhile,
southwesterly winds aloft continue over Deep South Texas, downstream
of a mid/upper level low pressure and trough situated over near the
Baja Peninsula. Embedded within this flow is a mid-level impulse
translating northeastward across the region tonight bringing a low
to medium (30-40%) chance of brief light rain showers, mostly
along/west of US-281, though could reach further east across the
Northern Ranchlands. Temperatures minimize in the 60s/70s by Monday
morning.

As the low pressure and trough aloft begin to progress east-
northeastward over northern Mexico, mainly dry and breezy conditions
return Monday, becoming windy on Tuesday as a pressure gradient
tightens; high pressure over the Gulf interacts with both a strong
low pressure system developing over the Central Plains as well as
with lowering heights over the Sierra Madre. The highest wind speeds
are likely to be along/east of US-281, where south-southeasterly
wind gusts up to 30+ mph during the day on Monday afternoon increase
to 40+ mph by mid-morning Tuesday, continuing through the late
afternoon hours. The NBM currently suggests up to a 30-50% chance of
wind gusts exceeding reaching and exceeding 40 mph across the Lower
and Middle RGV, where a Wind Advisory is certainly possible.
Following, there is a low (15-20%) chance of rain Tuesday night
across portions of the Rio Grande Plains and the Northern
Ranchlands, as convection develops ahead of the approaching trough
aloft and its associated surface low`s cold front. Additionally, a
Fire Danger Statement (RFD) is possible for Tuesday afternoon. In the
meantime, temperatures remain above average, maximizing in the
80s/90s, with the warmest day anticipated to be on Wednesday, in
which 90s are likely across all of inland Deep South Texas, even
into the coastal areas while temperatures remain in the 70s along
the immediate coast. Overnight temperatures minimize in the 60s/70s
through Tuesday night.

The next focus of the forecast will be the fire danger threat behind
the cold front, which is currently anticpated to arrive during the
day on Wednesday as the low pressure and trough aloft move over
central Texas. On the backside of the low, an upstream northwesterly
30-40 kt 925 mb LLJ brings downslope-compressed air into our CWA
from the Sierra Madre, crashing relative humidity values Wednesday
afternoon. The combination of breezy conditions and much drier air
advecting into the region from northwesterly winds on Wednesday and
northerly winds on Thursday may to lead to fire products, with RFDs
or Red Flag Warnings possible, dependent on wind speeds. Otherwise,
southeasterly winds return by Friday, becoming breezier over the
weekend, along with fire weather concerns prevailing each afternoon.
Highs in the 70s/80s on Thursday increase back to the 80s/90s over
the weekend with overnight lows warming from the 50s/60s to mainly
60s.

A medium risk of rip currents continues through Monday afternoon,
likely increasing to a High Risk of Rip Currents by the middle of
the week as winds increase.

&&

.AVIATION...
(12Z TAFS)
Issued at 611 AM CDT Mon Mar 9 2026

MVFR conditions are expected to continue at all the TAF sites for
the next couple of hours. Towards the end of the morning, the
southerly winds are expected to become more gusty with some gusts
up to 25 knots. This will allow for some of the lower-level clouds
to mix out and rise. Thus VFR conditions should return for the
rest of the day and through the evening hours. The winds should
weaken by this evening. MVFR ceilings are expected to return for
the overnight hours tonight.

&&

.MARINE...
Issued at 1040 PM CDT Sun Mar 8 2026

Gentle southeasterly winds and moderate (3-4 feet) seas tonight
increase to moderate to fresh south-southbeasterly winds with Small
Craft Exercise Caution (SCEC) conditions by Monday afternoon as a
pressure gradient tightens across the Lower Texas coastal waters.
SCEC and/or a Small Craft Advisory (SCA) are likely Tuesday as fresh
to strong south-southeasterly winds lead to moderate (5-6 feet, or
greater) seas. Winds and seas temporarily improve on Wednesday as a
cold front moves through, possibly during the afternoon and evening
hours, followed strong northerly winds Wednesday into Thursday with
additional SCA headlines likely as seas become rough. Winds and seas
improve Thursday night into Friday, with gentle to moderate
southeasterly winds resuming Friday and into the weekend. There is a
low (15-20%) chance of rain tonight and again Tuesday night into
Wednesday morning.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             87  72  86  72 /   0   0   0   0
HARLINGEN               90  69  90  70 /  10   0   0   0
MCALLEN                 93  73  94  74 /  10   0   0  10
RIO GRANDE CITY         94  70  96  70 /  10  10   0  20
SOUTH PADRE ISLAND      79  72  79  72 /   0   0   0   0
BAYVIEW/PORT ISABEL     87  70  86  70 /   0   0   0   0

&&

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

$$

SHORT TERM...65
LONG TERM....65
AVIATION...64-Katz