Area Forecast Discussion
Issued by NWS Brownsville, TX

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
501
FXUS64 KBRO 301132 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
632 AM CDT Tue May 30 2017

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

&&

.AVIATION...Light and variable winds with mostly clear skies
prevail across deep south Texas this morning. VFR conditions
expected to prevail for the next 24 hours. Light northeast winds
later this morning will veer to the east then southeast this
afternoon.

&&

.PREV DISCUSSION... /issued 355 AM CDT Tue May 30 2017/

SHORT TERM (Today through Wednesday): A much drier atmosphere
continues across Deep South Texas and the Rio Grande Valley this
morning. The 00Z BRO upper air sounding showed a precipitable
water value of 1.71 inches. Precipitable water values are expected
to fall to around 1.25 inches today with dry westerly flow aloft.
The latest model runs continue to indicate very low pops across
the area for today and tonight. Have lowered pops accordingly and
removed the mention of convection for today and through this
evening. Isolated showers will be possible across the lower Texas
Gulf waters and near the coast late tonight into Wednesday morning
as low level moisture begins to increase. Rain chances will begin
to increase across the area on Wednesday as abundant moisture
combined with a mid to upper level disturbance approaching from
the west and daytime heating. Temperatures are expected to remain
near to slightly above normal through the period.

LONG TERM (Wednesday Night through Monday): For Wed
night/Thu...will keep precip in the chance category area-wide as
abundant moisture and a difluent pattern aloft will still be in
place across deep south TX. High temperatures on Thursday are set
to reach near or somewhat below normal values due to abundant low
level moisture/additional cloud cover/precipitation.

For Fri/Sat...the Rio Grande Valley looks to be under a somewhat
drier quasi-zonal flow aloft with east to southeast onshore flow
at the surface. This pattern will lead to a sea breeze regime with
low chances of mainly afternoon showers/thunderstorms occurring
mostly east of Hwy 281. Due to somewhat less low level
moisture/cloud cover, high temperatures both days will be near or
somewhat above normal values.

For Sun/Mon...the medium range models differ quite a bit on their
solutions. The GFS is indicating that the forecast area will be
greatly affected by dry northwest flow aloft associated with a
strong ridge of high pressure over northwest Mexico while the
ECMWF shows a broad trough of low pressure over much of central TX
during this time that seeks to generate widespread, but low
amounts of precip, across deep south TX. Specifically for Monday,
the latest run of the ECMWF has fallen in line with the GFS
whereby a surface cold front looks to move through the forecast
area sometime Sunday night/Monday. Due to uncertainty between the
two models with regard to precip generation at the end of the long
term, will maintain low chances of showers/thunderstorms area-
wide for the two-day period. High temperatures both days will
reach near or somewhat above normal values.

MARINE (Today through Wednesday): Light to moderate winds and
low to moderate seas will prevail along the lower Texas coast
through the period. Northeast winds this morning will gradually
veer to the east then southeast by tonight. Isolated showers or a
thunderstorm is still possible across the Gulf waters early this
morning with better rain chances tonight and Wednesday.

Wednesday Night through Saturday: Modest winds/seas to predominate
through the period. Exceptions to this will be late Thursday
night/early Friday morning and late Friday night/early Saturday
morning when Small Craft Should Exercise Caution conditions look
to affect the Gulf waters of the lower TX coast.

&&

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

$$

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

63



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.