976 
FXUS64 KBRO 040255 AAB
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
955 PM CDT Sat Apr 3 2021

.DISCUSSION...

A few showers have developed to the north and west of Zapata and
Jim Hogg counties and are drifting east-southeastward. This
activity is expected to hold together over the next several 
hours, so have adjusted PoPs and added rain chances to most areas 
west of I-69C this evening. Most of this activity will taper off 
by the late morning hours Sunday.

&&

.PREV DISCUSSION... /issued 610 PM CDT Sat Apr 3 2021/ 

DISCUSSION...Updated for latest aviation discussion below.

AVIATION...VFR conditions will prevail through the period.
Ceilings will lower a bit later this evening and overnight, but 
should remain just above MVFR levels. Light to moderate easterly 
and southeasterly winds will also prevail through Sunday 
afternoon.

PREV DISCUSSION... /issued 240 PM CDT Sat Apr 3 2021/ 

SHORT TERM (Now through Sunday Night): Broad surface high pressure 
will persist over the region. A mid-level ridge will be undercut by 
a modest transiting short wave trough. This feature will bring upper 
moisture through the area in the short term. At the surface, modest 
return flow will support ample low clouds as well. There is some 
signal for precip around the periphery of the CWA, but not sold on 
anything too significant, and thus kept chances silent in the 
current forecast. Can't rule out isolated activity over the Sierra 
Madre Oriental overnight, or a few streamer showers. A few cells 
could drift east from interior Mexico toward the river. Temps will 
be near or slightly below normal during the short term. Upper 50s to 
lower 60s will prevail at night with mid 70s to mid 80s on Sunday.

Additionally, the combination of above normal astronomical high 
tides and modest waves approaching the Lower Texas Coast from the 
east-southeast could produce overwash and runup at the beaches of 
South Padre Island and Boca Chica Beach Sunday around high tide at 
1:41 PM.

LONG TERM (Monday through Saturday): A very weak 500 mb shortwave
axis moves over Texas and into the northern Gulf of Mexico on 
Monday. Limited instability and moisture may generate a slight 
chance of showers and isolated thunderstorms on Monday, mainly 
along the coast, as the upper level disturbance pushes eastward.
Otherwise, 500 mb ridging builds over deep south Texas Monday 
night resulting in dry weather through the rest of the week. The 
next upper level storm system quickly moves over the northern or 
central Plains around midweek. At the surface, the pressure 
gradient strengthens as low pressure develops across the Plains.
This will lead to breezy to windy conditions across the CWA Tuesday
and Wednesday afternoon. Very warm to hot conditions will 
prevail across the area each day. High temperatures start out near
normal on Monday then quickly warm through the rest of the week. 
Triple digit heat is expected across Starr and Zapata counties by 
Thursday and Friday. Lows each night will generally be in the mid 
to upper 60s to around 70. 

Relative humidity values and wind speeds are expected to remain 
below fire weather criteria for much of the week. However, any 
moderate breeze can create an elevated fire danger due to the near
explosive fuel state across deep south Texas. Burn bans remain in
effect across most of Deep South Texas, according to TFS.

MARINE (Now through Sunday Night): High pressure remains in 
control over the northwest Gulf. A modest onshore flow will 
persist in the short term. Look for moderate east to southeast 
winds and moderate seas through Sunday night.

Monday through Wednesday Night: High pressure anchored off the 
southeastern US coast will maintain southeasterly to southerly 
flow through the period. The pressure gradient is expected to 
strengthen Tuesday into Wednesday resulting in moderate to strong 
winds and building seas through late in the week. Small craft 
exercise caution to low end small craft advisory conditions will 
be possible by mid to late week. 

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  63  75  63  79 /  10  10  10  20 
BROWNSVILLE          63  78  63  82 /  10  10  10  20 
HARLINGEN            61  79  62  83 /  10  10  10  10 
MCALLEN              63  81  63  84 /  10  10  10  10 
RIO GRANDE CITY      62  84  62  86 /  30  20  10  10 
SOUTH PADRE ISLAND   65  69  65  72 /  10  10  10  20 

&&

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

$$

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HTTP://WEATHER.GOV/RGV

55-Adams