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
000
FXUS64 KBRO 160853
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
352 AM CDT Sun Jul 16 2017

.SHORT TERM (Now through Monday): Isolated convection is moving
south across the Northeastern Ranchlands and Gulf Waters early this
morning as the approaching inverted trough moves into the region.
This tropical wave will push into the RGV today with with increasing
deep layer moisture expected. In fact, model guidance from the GFS
has significantly increased POPs for today, with the GFS now coming
more in-line with the ECMWF and NAM. There is better agreement now
with forecasted sounding data with these main models all suggesting
PWATS increasing to around 2.0" or even a smidge higher for the
Lower RGV by this afternoon. Indeed, these higher PWATS are expected
to continue into Monday as well. As such, have trended the chances
for scattered showers and thunderstorms upwards through the day as
convective activity becomes more widespread during the heat of the
afternoon and as the atmosphere continues to moisten. The northern
portions of the CWA still look to have the best potential for
rainfall, however, showers/storms can develop across most any
location especially if enhanced by the seabreeze. Rainfall chances
will diminish somewhat overnight, but will ramp up again through the
day Monday. Showers/storms may be even more widespread to numerous
on Monday, given any leftover boundaries that may be present and
that the atmosphere will already be fairly saturated.

There is some possibility of locally heavy rainfall today and on
Monday given that models continue to indicate the deep layer
moisture. Still thinking that this would remain isolated, however,
if training of shower/storms occur or if storms become attached to
slow moving boundaries, nuisance urban or street flooding will be
possible. Isolated rainfall amounts of 1 to 2 inches or even locally
higher cannot be ruled.

Increasing cloud cover and any rainfall will keep temperatures
generally suppressed today, although still expect some triple digit
(100 to 103 degrees) heat along the Upper RGV and portions of the
Western Ranchlands. It will generally be in the lower to upper 90s
along the coast to the Mid Valley. High temps will be slightly
lower, maybe by a couple of degrees, for Monday.

.LONG TERM (Monday Night through Saturday): The forecast begins
with mid-level ridging over the Southwest into the central High
Plains and a weak, inverted 500mb trough over northeast Mexico and
Deep South Texas. The combination of deep moisture (precipitable
water values between 2.0 to 2.2 inches) and the mid-level weakness
overhead will support isolated to scattered convection across the
CWA Monday night. The mid-level weakness moves farther west over
Mexico on Tuesday leaving a daily sea breeze potential across the
area for remainder of the long term. Moisture surges north from
the southwest Gulf of Mexico Tuesday night into Wednesday
providing a better chance of showers and thunderstorms, mainly
along and east of the I-69C corridor on Wednesday. The latest
GFS/ECMWF are in good agreement with the higher pops on Wednesday.
If the trend continues, forecast pops for Wednesday may need to
be increased higher. Temperatures will be near to slightly above
normal through the period. High temperatures each day will range
from the low to mid 90s near the coast to the upper 90s to triple
digits across the west. Overnight low temperatures will remain in
the mid to upper 70s to around 80 along the beaches.

&&

.MARINE (Now through Monday): At 3 A.M., Buoy 42020 was reporting
light south winds of less than 10 knots and seas at 1 foot. The
weather pattern will not change through the remainder of the
weekend and into Monday with broad surface high pressure
maintaining light winds and seas of 2 feet or less. However,
scattered showers/storms will be possible across the coastal
waters through much of the period.

Monday Night through Thursday Night: Generally favorable marine
conditions expected through late week as broad high pressure remains
in control across the Gulf. Light to moderate south to southeast
winds and low to moderate seas will prevail along the lower Texas
coast through the period. Showers and thunderstorms will be possible
at times across the coastal waters Monday night through Thursday
night.

&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  92  77  93  79 /  40  30  40  20
BROWNSVILLE          92  77  92  78 /  40  30  30  20
HARLINGEN            95  76  95  77 /  40  30  40  20
MCALLEN              99  78  98  77 /  30  30  40  20
RIO GRANDE CITY     100  76 100  77 /  30  30  40  30
SOUTH PADRE ISLAND   85  80  86  80 /  40  30  40  20

&&

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

$$

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

Short Term...69
Long Term...63
Graphicast/Upper Air...56



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