National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS64 KBRO 281125 AAB
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
625 AM CDT Sun Apr 28 2024

...New AVIATION...

.SHORT TERM...
(Today through Monday)
Issued at 317 AM CDT Sun Apr 28 2024

The start of the short term forecast period will see the influences
of an upper-level trough diminish over Deep South Texas and the Rio
Grande Valley, which will see the southwesterly flow aloft become
more zonal. SPC has Deep South Texas and the Rio Grande Valley in a
General Thunderstorm Outlook for today and Monday. However, part of
Northern Zapata is in a Marginal Risk (level 1 of 5) for severe
weather on Monday. For the showers and thunderstorms on Sunday, a
cold front and dry line upstream could merge north of the region.
While previous runs of CAMs models showed that theses showers and
thunderstorms could move into the Northern Ranchlands, the current
run does not reflect this happening. NBM does try to produce
isolated showers and thunderstorms for Northern Ranchlands still.
Looking into forecast soundings, shows that the environment stays
pretty capped leading an unfavorable environment for showers and
thunderstorms. Thus keeping rain chances at 20 percent for today.

For tomorrow, the situation is a bit different with an mid-level
shortwave potentially aiding in the development of showers and
thunderstorms. The atmosphere becomes marginally unstable with
MUCAPE around 2000 J/kg with model soundings indicating a weakening
of the cap later Monday, which would open a brief opportunity for
showers and thunderstorms to develop. However, a weak mid-level
ridge to the south of the area maintains mid-level dry air which
could hinder the development of the mentioned showers and thunderstorms.
Model and WPC QPF is also pretty limited, thus making the development
of showers and thunderstorms questionable at best for Monday.

As for temperatures, with the southerly to southeasterly flow at the
surface bringing in more humid, warm air, temperatures are expected
to stay pretty warm for the short term forecast period. High
temperatures for today and Monday are expected to be in the 90s for
most of the area, except along the coast and on the island. As for
the low temperatures for tonight, all of Deep South Texas and the
Rio Grande Valley is expected to be in the 70s.

Lastly, for anyone planning on going to the beach, High Risk of Rip
Currents has been extended through Monday on all the beaches as the
wave heights around 6 and swell period remain high around 8
seconds.

&&

.LONG TERM...
(Monday night through Saturday)
Issued at 317 AM CDT Sun Apr 28 2024

For the long term there will be a quasi-zonal midlevel flow
covering much of the CONUS with a few shortwaves riding over the
top of the subtropical ridge centered over Central Mexico. Farther
north low pressure troughs will be traversing the Rockies and
North and Central Plains with the strongest trough possibly
pushing a surface cold front into Central Texas next Friday and
Saturday. Southerly flow persist through the week with a moderate
pressure gradient maintaining a steady flow of low level moisture
(modest dew points in the U60s/M70s) and warm temperatures. Rain
chances continue to look limited with best chances Tuesday and
Wednesday and again Friday and Saturday. There remains uncertainty
on the timing of the shortwaves and areal coverage among latest
model projections with best overall coverage favoring Tuesday with
20-30% for most of the region with northern and Western areas of
Deep South Texas seeing best chances, albeit low Wednesday,
Friday- Saturday. It is May (in a few days) and the atmosphere is
likely to be in a conditional instability state. Forcing from the
above mention shortwaves or outflow from storms further north may
be sufficient to produce a few strong thunderstorms any of the
days mentioned. Some of the storms may be accompanied by gusty
winds, moderate to heavy rainfall and some hail.

Seasonal warm to hot temperatures with the region under the
influence of the northern edge of the subtropical ridge. Maximum
Temperature anomalies range from 2-5 degrees above early May
averages, while Minimums look to be a bit warmer 4-7 degrees above
mainly due to higher dew points as Gulf water temperatures are
already in the mid to upper 70s. Heat indices also, will show an
increase through mid week with maximums ranging 100-106 degrees.

&&

.AVIATION...
(12Z TAFS)
Issued at 617 AM CDT Sun Apr 28 2024

Mostly MVFR conditions are expected through the TAF cycle at all
TAF sites, however during the afternoon seems to be the best time
for ceilings to rise to VFR conditions, before coming back down to
MVFR tonight. Southerly to southeasterly winds are expected to
weaken during the course of the day as the pressure gradient
relaxes, while still being southerly overall.

&&

.MARINE...
Issued at 424 AM CDT Sun Apr 28 2024

Decided to extend the Small Craft Advisory for the Laguna Madre
until 5 PM. Observation decks along the Laguna continue to hover
at or just below 20 kts. Pressure gradient remains sufficiently
strong as well as low level inflow is likely to be enhanced by
ongoing convection over Central and North Texas allowing winds to
reach and exceed 20 knots beyond 7 AM.

&&

.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE             92  77  91  77 /  10   0  20  10
HARLINGEN               94  74  92  74 /  10   0  20  10
MCALLEN                 94  76  94  77 /  10   0  20  10
RIO GRANDE CITY         94  73  94  75 /  10   0  30  10
SOUTH PADRE ISLAND      83  76  81  76 /   0   0  10  20
BAYVIEW/PORT ISABEL     91  75  87  75 /  10   0  20  20

&&

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

GM...Small Craft Advisory until 5 PM CDT this afternoon for GMZ130-
     132-135.

     Small Craft Advisory until 7 AM CDT Monday for GMZ150-155-170-
     175.

&&

$$

SHORT TERM...64-Katz
LONG TERM....59-GB
AVIATION...64-Katz