000
FXUS64 KBRO 230925
AFDBRO

Area Forecast Discussion
National Weather Service Brownsville TX
425 AM CDT Sun Jul 23 2017

.SHORT TERM (Now through Monday): A weak mid-level low will
continue to fill as it moves into the upper Texas coast underneath
a broad ridge of high pressure located over the Central US. Most
of the moisture and instability with the disturbance will be well
to our north with mainly only some upper-level cirrus clouds
moving overhead of Deep South Texas this weekend. The main story
will be the hot and breezy conditions as surface high pressure
over the northern Gulf of Mexico maintains strong southeast flow.
Despite some cirrus cloud cover expected, temperatures will still
be able to climb into the upper 90s to above 100F for much of the
area. Daytime mixing should keep us under Heat Advisory criteria,
but Heat Indices will range from 105-110F again for much of the
Rio Grande Valley. Wind gusts of 30 to 35 mph will also be common
as low level jet winds mix down to the surface Sunday afternoon
and continue through just after sunset. Monday, similar conditions
will continue with hot temperatures and breezy winds during the
afternoon. Rain chances are very low through the short term as
model guidance keeps RH values generally from 30 to 50% below
700mb.

.LONG TERM (Monday Night through Saturday): 500mb subtropical
ridge across the south-central United States Monday and Tuesday is
progged to shift slightly westward Wednesday. Low to mid level
moisture is expected to increase slightly across the CWA Tuesday
and this will provide at least a slight chance of showers and
thunderstorms...mainly across the coastal sections...Tuesday and
Wednesday. A 500mb shortwave trough developing across the
southeast U.S. Thursday should amplify the upper level ridge
across the southwest and south-central U.S. and subsidence will
increase across south Texas through the rest of the week. Rain
chances will diminish Thursday into Friday with not much in the
way of rain chances Saturday. Temperatures will remain near normal
to above normal Mon night through Saturday.
&&

.MARINE (Now through Monday): Strong southeast flow will continue
through the day Sunday with a tight pressure gradient resulting from
a surface high over the northern Gulf of Mexico and low pressure
in the Central Plains. Winds may reach or exceed 20 kts over the
Laguna and nearshore Gulf waters, so have issued a Small Craft
Advisory for winds from 18Z to 01Z. Monday, winds should be
slightly lower, but Small Craft Exercise Caution conditions for
winds will be likely.

Monday night through Thursday...Moderate to strong southeast winds
will prevail across the coastal waters Mon night as surface
high pressure across the eastern Gulf of Mexico and surface low
pressure across northern Mexico provides a strong pressure
gradient across the lower Texas coast. The pressure gradient
will weaken slightly across the western Gulf of Mexico on Tuesday.
Moderate southeast winds will prevail across the lower TX coast
on Tuesday. The pressure gradient will remain relatively weak
across the western Gulf of Mexico Wednesday and Thursday. Light to
moderate southeast winds should prevail across the coastal waters
Wednesday and Thursday.
&&

.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL  96  80  96  81 /  10   0  10  10
BROWNSVILLE          94  79  94  80 /  10   0  10  10
HARLINGEN           101  78 100  79 /  10   0  10  10
MCALLEN             103  80 103  80 /  10   0  10  10
RIO GRANDE CITY     104  78 104  79 /   0   0  10  10
SOUTH PADRE ISLAND   91  82  90  82 /  10   0  10  10
&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Advisory for winds from 1 PM this afternoon to 8 PM
     CDT this evening for GMZ130-132-135-150-155.
&&

$$

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

65/61/62