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Area forecast discussion
National Weather Service Brownsville Texas
348 PM CDT Thu Mar 30 2017

Short term (tonight through Friday night): the weak cold front that
moved through the area this morning is well off the Lower Texas
coast this afternoon and surface high pressure is settling in over
deep south Texas. Satellite imagery and surface observations show
sunny skies and lightening winds as the pressure gradient relaxes
and strong subsidence filters in behind the mid-level trough axis.
Winds this evening will continue to veer to the east and eventually
southeast tonight as high pressure moves eastward across the
northern Gulf of Mexico. Tonight, there is a small window of
opportunity for patchy fog across the lower Rio Grande Valley due to
subsidence aloft and light winds expected Friday morning, but
confidence is low given the lack of surface moisture.

Friday, south/southeasterly flow will return as the surface high
moves eastward and another area of low pressure develops across West
Texas. Winds will be breezy to windy in the afternoon with gusts
approaching 30 mph at times. Temperatures will heat up again to the
lower 90s for most areas, which is about 10 degrees above normal
highs for the end of March. Dry conditions are expected through the
rest of the period with relative humidity values below 25% above 850mb.

Long term (saturday through thursday): a deep mid level low will be
spinning over The Four Corners Sat, moving slowly east and producing
pressure falls over West Texas and the Texas Panhandle. This will
keep the deep south Texas wind machine on for the day, and will
support warm weather with high temps in the 90s. An eastward moving
boundary associated with the system will move across Texas on Sat,
producing stronger weather over East Texas, but resulting in only a
few showers for the County Warning Area Saturday afternoon.

Depending on the progressiveness of the consolidating mid level
impulses over the Mexican plateau/Texas Big Bend/Rio Grande Valley
Saturday night, a more substantive risk for strong thunderstorm
development could evolve across parts of the lower Rio Grande Valley
through the deep south Texas through Sunday. Better boundary
layer moisture return, increasing vertical shear and forcing for
large scale ascent could all contribute to organizing/upscale
growing convective development with small hail/wind potential
through Sunday. The mid level trough axis will swing past later
on Sunday with drier air and upstream ridging taking over Sunday
night through Monday.

A mid level short wave trough will follow-up by diving out of the
Pacific northwest and into the High Plains Monday night, and
pressure falls over the plains will help local winds swing rather
quickly back to southeast. The main system will remain farther
north, over the Central Plains, with a cold front pushing into
central Texas, ahead of high pressure over The Four Corners Tuesday
night. That front may generate a few showers Wednesday and Wednesday
night, but mainly increased cloud cover. High pressure and drier air
will push into the region on Thursday.

&&

Marine (now through Friday night): winds will diminish across the
Lower Texas coastal waters this afternoon with slowly subsiding seas
as high pressure moves eastward and relaxes the pressure gradient. A
Small Craft Advisory is currently in effect for the Gulf waters
through 7 PM CDT. As low pressure develops across West Texas Friday
morning, winds will strengthen out of the southeast through Friday
afternoon. Another Small Craft Advisory may be needed.

Saturday through tuesday: southeast winds on the Gulf will be
moderate to fresh with elevated seas through Sunday. Winds and
waves may rise above Small Craft Advisory criteria at times. A
front will move into the area on Sunday, shifting winds to
northwest Sunday night, and marginal Small Craft Advisory
conditions may continue on the Gulf into Mon morning. Winds will
be weaker than the Gulf on the Laguna Madre during the period,
though small craft should exercise caution conditions will be
possible at times. Winds will Switch Back to moderate southeast
quickly after Sunday, by Mon evening, though moderate seas will
persist.

&&

Preliminary point temps/pops...
Bayview/Port Isabel 65 90 74 85 / 0 0 10 10
Brownsville 64 92 74 86 / 0 0 10 10
Harlingen 60 93 73 89 / 0 0 10 10
McAllen 60 92 73 92 / 0 0 10 10
Rio Grande City 60 96 71 95 / 0 0 10 10
South Padre Island 71 84 74 82 / 0 0 10 10

&&

Bro watches/warnings/advisories...
Texas...none.
GM...Small Craft Advisory until 7 PM CDT this evening for gmz150-155-
170-175.

&&

$$

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