National Weather Service National Headquarters

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

000
FXUS64 KBRO 240509
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
1209 AM CDT Thu Aug 24 2017

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

&&

.AVIATION...VFR conditions will prevail tonight through most of
the day Thursday. Winds will become light and variable overnight
before increasing and becoming easterly by midmorning. Convection
along the seabreeze possible Thursday, but coverage is expected
to remain isolated in nature. Shower and thunderstorm chances ramp
up going into Thursday evening as Tropical Storm Harvey moves
closer to the Texas coastline and as such have added in a TSRA
line to the package.

&&

.PREV DISCUSSION... /issued 634 PM CDT Wed Aug 23 2017/

DISCUSSION...Updated for latest aviation discussion below.

AVIATION...Only minor adjustments made to the previous issuance
of TAFs. VFR will prevail this evening and through the overnight
hours as moderate surface winds diminish to light and variable
levels. Tomorrow, convection is expected along the seabreeze
boundary, but is expected to remain too isolated to warrant a
mention in the current TAF issuance.

PREV DISCUSSION... /issued 350 PM CDT Wed Aug 23 2017/

SHORT TERM (Now through Thursday Night): Seabreeze convection is
developing over the eastern and central portions of Deep South
Texas and the Rio Grande Valley right now. This should fade around
sunset, leaving only streamer activity tonight over the Lower
Texas coastal waters and immediate three coastal counties. Another
round of seabreeze convection is likely tomorrow. Tomorrow night,
however, rapidly increasing precipitation chances are forecast as
organizing Tropical Depression Harvey moves closer to the Texas
coastline. A Storm Surge Watch is in effect for Padre Island north
of Port Mansfield. Residents of Deep South Texas and the Rio
Grande Valley are urged to monitor this developing weather
situation through the next few days.

LONG TERM (Friday through Wednesday): The main concern for
start of the long term period remains Harvey. Mid level weakness
over the northwest Gulf of Mexico will continue to allow Harvey to
move northwest to north-northwest towards the middle Texas coast. On
this forecast track, Harvey is expected to pass northeast of Deep
South Texas. The latest National Hurricane Center forecast brings
the closest point of approach with Harvey about 90 miles to the
northeast of Brownsville or around 70 miles northeast of Port
Mansfield Friday morning. The system will only move farther away
toward the middle Texas coast during the day on Friday.

Rain chances across the eastern sections of the CWA will peak on
Friday with two to three of inches of rainfall possible across much
of the area with locally four inches near the coast. Some rain bands
training from north to south may occur, which would appear to be the
biggest threat for potential nuisance flooding. Gulf water runup to
the dunes and minor beach erosion will be possible through Friday
morning. Cloud cover will be plentiful Friday and Saturday, with low
temps in the 70s and slightly depressed high temperatures. High
temperatures on Friday will be in the upper 80s to lower 90s across
eastern sections, a skosh below normal. High temperatures will
gradually increase on Saturday into early next week courtesy of
drier air on the west side of the circulation over East Texas and is
brought south. Upstream ridging will build over the region early
next week, resulting in fewer clouds and warmer temperatures.

MARINE (Now through Thursday Night): Buoy 42020 reported
northeast winds around 10 knots gusting to around 14 knots with
seas slightly over 2.5 feet with a period of 6 seconds at 15
CDT/20 UTC. Favorable marine conditions are expected tonight under
the influence of weak low pressure. Tomorrow and tomorrow night,
however, rapidly deteriorating marine conditions are likely as
organizing Tropical Depression Harvey moves closer to the Texas
coastline. A Tropical Storm Watch and a Hurricane Watch are in
effect for the Lower Texas coastal waters. Mariners are urged to
monitor this developing weather situation through the remainder of
this week.

Friday through Monday night: On going hazardous marine conditions
will continue across the lower Texas Gulf waters on Friday as Harvey
skirts the marine areas. The Laguna Madre will remain relatively
protected from high seas. Strong northwest winds Friday morning will
gradually diminish by late Friday night into Saturday. However,
hazardous seas will continue on the Gulf waters Friday into Saturday
resulting in small craft advisory conditions for high seas. Winds
will shift to south or southwest Friday night and Saturday, as the
circulation center over the Gulf moves north of the area. Improved
marine conditions will prevail through the rest of long term marine
forecast.

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Hurricane Watch for TXZ251.

     Tropical Storm Watch for TXZ256-257.

GM...Hurricane Watch for GMZ135-155-175.

     Tropical Storm Watch for GMZ130-132-150-170.

&&

$$

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

58/54