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Area forecast discussion...updated 
National Weather Service Brownsville Texas
621 am CDT Friday Jul 31 2015

Discussion...updated for latest aviation discussion below.

Aviation...satellite images and surface observations indicate
mostly high clouds across the County Warning Area this morning. Visibilities were
near 6sm with fog at khrl. Expect MVFR conditions this morning
with patchy fog. Otherwise...VFR conditions will prevail today
even as low to middle level moisture increases across the coastal
sections of deep south Texas as a weak 500mb low/inverted trough
across the north central Gulf of Mexico moves westward this
afternoon. Isolated convection will approach the Lower Texas coast
this afternoon. &&

Previous discussion... /issued 311 am CDT Friday Jul 31 2015/
short term /today through Saturday/...scattered showers and
thunderstorms continue to develop across the north central Gulf of
Mexico this morning associated with a weak 500mb low/inverted
trough. Some of the outflow from the convection may reach the
coastal waters today and reach the coastal sections of the County Warning Area
this afternoon. Low to middle level moisture will increase across the
western Gulf of Mexico today into tonight as the weak upper level
feature across the central Gulf moves westward. This will provide
a slight chance to chance of showers and thunderstorms across
portions of the Rio Grande Valley and northern ranchlands tonight
and a slight chance of showers and thunderstorms Saturday. The
increase in moisture will provide additional clouds across the County Warning Area
this afternoon and this will ameliorate the hot temperatures and
high heat index values today.

Long term /Saturday night through Thursday/...middle level ridge
shifts west into The Four Corners region early in the period
while shortwave trough axis remains embedded within the southeast
periphery of the ridge. Trough continues to support a stationary
front from the northeast coast of Florida SW to western southern Texas
Gulf Coast. Weak low level moisture convergence will generate
showers and storms over the Gulf waters and coastal counties Sat
night to Sunday. Better chances for rain remain over the Gulf
waters but isolated storms could develop in the Lower Valley. By
early next week this boundary weakens and becomes not so well
defined as it lifts moisture north to northwest across the area.
During that period...Monday through Tuesday ... will still be
very limited keeping a very low chance of showers. There is
lingering moisture over the Gulf waters Wednesday into Thursday
but with anticyclone shifting east into the southern region of Texas
suppressing any low level moisture limiting any convection
development. Dry conditions will continue over the area through
Friday of next week. Due to cloud cover and slight chance of
shower activity early in the period...expect high temperatures to reach
the triple digits mainly out west towards McAllen westward and
along Highway 281 through the week. Low temperatures remain near 80
through the week. through Saturday...seas were near 1 foot with
south winds near 8 knots at buoy020 early this morning. Light
and variable winds will prevail across the coastal waters today
as weak high pressure builds across the western Gulf of Mexico
this afternoon in the wake of an outflow boundary from convection
across the northwest Gulf of Mexico this morning. Light southerly
winds will prevail across the western Gulf tonight with broad and
weak low pressure across the northern Gulf. Light and variable
winds will prevail across the Lower Texas coast Saturday as the
pressure gradient remains weak across the western Gulf. Winds and
seas will be higher in and near thunderstorms that develop across
the western Gulf today through Saturday as a weak 500mb low/inverted
trough over the central Gulf moves westward.

Saturday night through Thursday...middle level ridge remains in
control across Gulf waters with northeast flow aloft while a weak
shortwave embedded within the anticyclonic flow moves southwest
into Lower Texas Gulf waters early in the period. This unstable
airmass will support for showers and storms to develop Sat night
through Monday. This boundary/stationary front will not deviated
much remaining over the area through the weekend allowing for this
unsettle weather to prevail until Sun afternoon. It then lifts
north/northwest as a warm front Monday into Tuesday improving weather
conditions over the Gulf and Laguna Madre. Winds will remain light
to moderate with seas around 2 to 3 feet with no significant build
as the winds remain no more than 15 knots across the Gulf. Into
next week...ridge builds across the Gulf with low chance of
showers and temperature gradient strengthening during the day. This will
allow for southeast winds to increase along the Laguna Madre with scec
through the afternoon hours weakening during the day through the
whole week. Further into the Gulf...gradient will not be as tight
not supporting scec conditions.

Bro watches/warnings/advisories...


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