070 
FXUS64 KBRO 112347 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
547 PM CST Thu Mar 11 2021

.DISCUSSION...Updated for latest aviation discussion below.

&&

.AVIATION...Mostly clear skies and moderate to breezy southeast
winds prevail across deep south Texas this evening. MVFR to IFR
ceilings are expected to develop later this evening into the 
overnight hours as low clouds return. Moderate southeast winds
will persist tonight through Friday morning. Ceilings will 
gradually lift mid to late Friday morning with VFR conditions 
expected in the afternoon. Southeast winds will increase and 
become breezy by mid to late morning on Friday. 

&&

.PREV DISCUSSION... /issued 232 PM CST Thu Mar 11 2021/ 

SHORT TERM (Tonight through Friday Night): The deep South Texas 
wind machine is on, with strong high pressure over the Gulf 
interacting with lower pressure inland and upstream. Extended the
rip current statement through tonight with a high rip current 
risk continuing, including a stronger longshore current which 
could enhance the traditional rip current threat. A persistent 
similar pattern will keep moderate southeast winds going overnight
and into Friday. Big picture has ridging over the Gulf and a 
slowly maturing mid level low edging into the Desert Southwest
through Friday night. Low temps will be mainly in the 60s and 
highs on Friday will be above normal from the mid 80s to lower 
90s. The next approaching cold front is not expected until Sunday.

LONG TERM (Saturday through Thursday): The mid level ridge 
sitting over the Gulf of Mexico will weaken through the remainder
of the weekend as a 500 mb trough works into the Southern Plains 
by Monday and ejects northeast across the Great Lakes late 
Tuesday, leaving generally zonal flow across Texas into late next 
week. At the surface, expect breezy to windy conditions on 
Saturday into Sunday before a cold front arrives. A Wind Advisory
may be needed on Saturday.

Another bout of low pressure will work through the Plains by mid 
next week with another cold front arriving through Deep South 
Texas on Wednesday. The best chance of rain through the long term 
period will reside with each front. A weak coastal low will 
develop behind the front on Sunday combining with several days of 
moderate moist southerly flow to help boost rain chances. MUCAPE 
values for the front on Wednesday are currently above 1700 j/kg 
with bulk shear topping 40 kts and a lapse rate near 8 C/km, 
leading to better convective chances than on Sunday. Have kept 
overall POPs between 20 and 30 percent.

Overall, well above normal temperatures will continue before the 
cold front on Sunday, dipping into more seasonal lows and only 
slightly above normal highs. Temperatures will warm slightly on 
Tuesday into Wednesday before the second front brings back normal 
highs to end the week. Very dry air will arrive behind the front 
on Sunday, with RH values out west dropping below 20 mph. At this 
time, 20 foot winds remain borderline for fire weather concerns. A
Fire Danger Statement may be needed.

MARINE:
Tonight through Friday Night...Extended the SCA for the offshore 
waters into tonight as wave heights at TABS Buoy K remain at 
around 7 ft and will continue to be supported by persistent 
southeast winds. The current forecast calls for 5 to 7 feet wave 
heights offshore through the short term, meaning the SCA may 
continue on Friday and Friday night, with SCEC conditions possible
on the other marine zones.

Saturday through Thursday...High pressure across the Gulf of 
Mexico and low pressure across the Plains will keep moderate 
southerly flow across the coastal waters Saturday into Sunday 
before a cold front brings moderate northerly winds Sunday into 
early Monday. Southerly flow will return briefly into Tuesday as 
the next system works into the Plains, followed by another cold 
front on Wednesday with another round of northerly winds. Seas
will remain elevated into Monday, with improving conditions into 
Wednesday before becoming elevated again late into next week. 
There is a slight chance of showers and thunderstorms with each 
front on Sunday and Wednesday. Small Craft Advisories may be 
needed Saturday into Monday, and again on Thursday. 

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  68  79  66  78 /   0   0   0   0 
BROWNSVILLE          70  82  69  81 /   0   0   0   0 
HARLINGEN            69  85  68  83 /   0   0  10   0 
MCALLEN              69  88  69  86 /   0   0   0   0 
RIO GRANDE CITY      68  91  69  90 /   0   0   0   0 
SOUTH PADRE ISLAND   66  70  66  72 /   0   0   0   0 

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...High Rip Current Risk through late tonight for TXZ256-257-351.

GM...Small Craft Advisory until 6 AM CST Friday for GMZ170-175.

&&

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

63-KC