Drought in Texas, March 27 to 31, 2018

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
1159 PM CDT Mon Mar 26 2018

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

&&

.AVIATION...Low clouds are drifting north along the coast tonight,
producing MVFR ceilings locally. A healthy, low level inversion
seen on the previous evening's sounding appears to remain in
place. Model guidance keeps MVFR ceilings going along the coast,
including BRO and HRL, through the day on Tuesday, with clearing
by mid day farther inland, like at MFE, as moderate to breezy
south southeast winds develop.

&&

.PREV DISCUSSION... /issued 617 PM CDT Mon Mar 26 2018/

DISCUSSION...Updated for latest aviation discussion below.

AVIATION...Breezy to windy conditions are expected through the
next 24 hours with high and low pressure interacting. MVFR cloud
decks are anticipated tonight, otherwise VFR is likely through
the rest of the period.

PREV DISCUSSION... /issued 233 PM CDT Mon Mar 26 2018/

SHORT TERM (Now through Tuesday Night):Strong southwest flow
prevails aloft over deep south Texas in between strong upper level
high pressure over the northern Gulf and upper level low pressure
digging southeastward into the southwest US/northwest Mexico.
This pattern will slowly progress eastward through the period. As
it does, the relatively dry and capped low levels over the RGV
will moisten and destabilize Tuesday afternoon into Tuesday night.
After a precipitation free day with somewhat above normal high
temperatures in the mid 80s coast/mid 90s west on Tuesday, low
chances of showers/thunderstorms will creep into the forecast
area- wide Tuesday night as a weak cold front approaches from the
north. As moisture will not yet be well-pooled over the region
Tuesday night, rainfall amounts are expected to be low.

LONG TERM (Wednesday through Monday):A deep mid level trough/low
will be situated over New Mexico 12Z Wed will be making its way
through Texas during the day slowly filling in Wednesday night
and Thursday as it tracks east of the state. The trough will drag
a cold front front through South Texas Wednesday night and off the
Lower Texas coast Thursday morning bring with it a chance of
thunderstorms and slightly cooler conditions. Mid/upper level
ridge builds in from the west for late in the week and over the
weekend with drier conditions and mild to warm days and cool to
mild nights.

SPC Day 3 Convective Outlook continues to advertise the Northwest
Ranch lands areas of Zapata, western Starr, most of Jim Hogg and
western Brooks counties within a Slgt Risk of Severe T-storms for
Wednesday through early Thursday. While most of the RGV and
eastern portions of the CWA remain under a marginal risk of Severe
T-storms. Convection is likely to be initiated along the pre-
frontal trough or the front itself well north of our area early
Wednesday or Wed afternoon. Then propagate into our area Wednesday
evening and track southeast overnight. Models continue to come
into better agreement with the front reaching the Lower Valley
around sunrise Thursday moving off the coast through the morning
hours. The best chances for thunderstorms impacting DSTX and the
RGV remain overnight Wed with models suggesting a wide band of
instability and large scale lift in advance of the upper trough
where cape values remain rather high between 1800-3000j/kg.
Moisture values will be maximizing between 1.7-1.9 inches with dew
points around 70 degrees if not higher and bulk shear values will
averaging around 50 knots. So any ongoing convection will likely
be sustained especially in the west and central early on in the
event. GFS and EC also continue to show the potential for a squall
line of sorts developing and moving across the Lower RGV Thursday
morning. Confidence remains above average with models in good
agreement and consistency. Fly in the ointment would be for the
late night/early morning arrival of front and trough itself with
no heating to add additional instability and lift to the low
levels and a weak surface inversion remaining intact over the
Lower valley.

The mid/upper trough axis looks to be east of the area by 00Z
Friday with rapid clearing and no lingering low level clouds
anticipated at this time. Mid level ridge builds in from the west
through the weekend with deep layer dry air to dominate much of
south Texas. This will result in Sunny warm days and clear cool to
mild days.

MARINE:(Now through Tuesday Night): A tight pressure gradient
between strong high pressure over the northern Gulf and strong low
pressure over the central plains will continue to support moderate
to strong (15 to 25 knots) southeast winds and building seas tonight
into Tuesday. Small craft advisory currently in place across the
lower Texas Gulf coast waters will likely persist into much of
Tuesday as the waters remain agitated.

Wednesday through Saturday...Cold front will be approaching later
Wednesday and passing through the Gulf waters Thursday morning.
Moderate to strong southerly flow and moderate to high seas will
be ongoing Wednesday with a slow lowering of winds during the
later half of Wednesday as gradient weakens with the approach of
the front. A slow Se movement of the front may delay the
diminishing of the winds until Wednesday evening. A line of
thunderstorms looks to accompany the frontal passage Thursday
resulting in brief stronger north-northeast winds. Weak surface
high pressure builds in behind the front later Thursday and Friday
with a light to moderate northeast flow. surface ridging tracks
east Friday night and Saturday with southeast winds becoming
established.

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Advisory until 7 PM CDT Tuesday for GMZ150-155-170-
     175.

&&

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

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Hazardous Weather Outlook...UPDATED
National Weather Service Brownsville TX
1011 PM CDT Mon Mar 26 2018

TXZ248>257-271100-
Zapata-Jim Hogg-Brooks-Kenedy-Starr-Hidalgo-Inland Willacy-
Inland Cameron-Coastal Willacy-Coastal Cameron-
1011 PM CDT Mon Mar 26 2018

This Hazardous Weather Outlook is for portions of Deep South
Texas.

.DAY ONE...Rest of Tonight

There is a moderate risk of rip currents at the beaches of South
Padre Island and at Boca Chica Beach.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

An elevated risk of rip currents is likely at the local beaches
Tuesday through Saturday.

Strong to severe thunderstorms, producing large hail, damaging
winds, and flash flooding, are possible Wednesday evening and
Wednesday night.

.SPOTTER INFORMATION STATEMENT...

Skywarn spotter activation will not be needed.

GMZ130-132-135-150-155-170-175-271100-
Laguna Madre from the Port of Brownsville to the Arroyo Colorado-
Laguna Madre from the Arroyo Colorado To 5 NM north of Port
Mansfield TX-
Laguna Madre from 5 nm north of Port Mansfield to Baffin Bay TX-
Coastal waters from Port Mansfield to the Rio Grande out 20 nm-
Coastal waters from Baffin Bay to Port Mansfield out 20 nm-
Waters from Port Mansfield to the Rio Grande extending from 20 to
60 nm-
Waters from Baffin Bay to Port Mansfield extending from 20 to
60 nm-
1011 PM CDT Mon Mar 26 2018

This Hazardous Weather Outlook is for portions of The Gulf of
Mexico and The Laguna Madre.

.DAY ONE...Rest of Tonight

A Small Craft Advisory is in effect for the Gulf of Mexico waters
until 7 PM CDT Tuesday.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Additional Small Craft Advisories are likely to be needed along
the Lower Texas Coast Tuesday through Thursday night.

Strong to severe thunderstorms, producing large hail, damaging
winds, and waterspouts, are possible Wednesday night through
Thursday morning.

.SPOTTER INFORMATION STATEMENT...

Skywarn spotter activation will not be needed.