Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 201141 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
541 AM CST Mon Feb 20 2017

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

&&

.AVIATION...A line of showers and a few embedded thunderstorms
will are currently moving through KHRL and will be approaching
KBRO with the hour. Although overall thunderstorm activity has
decreased over the last hour or two...do expect at least some
lightning and gusty winds. Cigs and visbys will generally lower
briefly as the line of storms pass. There will be some
improvement behind the line...although any additional area of rain
moving east across the Western Ranchlands will keep the rainfall
and MVFR cigs in the forecast through the morning. Conditions will
rapidly improve this afternoon...as winds shift to the northwest
as drier air returns. There is the potential for some BR formation
at KBRO Monday night and have hinted at some lower visibilities.

&&

.PREV DISCUSSION... /issued 352 AM CST Mon Feb 20 2017/

SHORT TERM (Now through Tuesday): The line of showers and
embedded thunderstorms will continue to push eastward into Hidalgo
and Brooks Counties towards the coast through the early morning
hours. Although the overall threat of severe weather has decreased
overnight...as few isolated storms could still produce marginally
severe hail. The large capping inversion evident on the 00Z
sounding will be difficult to overcome and storms should remain
elevated. The good news is that the storms are brining the first
decent rainfall amount that we have had in sometime...with radar
estimates of at least an inch to inch and a half in some of the
stronger cells.

The storms will push through the Mid and into the Lower RGV and
across the Northeastern Ranchlands by about daybreak. Winds will
become west to northwest as the weak surface low exits to the east
with rainfall clearing form west to east. However...lingering
showers and maybe an isolated thunderstorms will continue across
the coastal counties through much of the day before the 500mb low
deepens and quickly moves eastward along the Northern Texas and
Louisiana Gulf Coast Monday evening.

Once this occurs...a stronger surge of northwest winds will bring
much drier air back in the the region. This dry airmass will
allow for dry and rather warm conditions to return on Tuesday.

LONG TERM (Tuesday Night through Sunday): Weak ridging aloft and
surface high pressure will give way to a fairly zonal mid level
pattern on Wednesday. A plains storm system will send the
trailing edge of a cold front into the area on Fri. However, with
little in the way supporting dynamics, all we`ll see is a brief
wind shift. Winds will shift to northwest by afternoon, but back
door high pressure moving into the northwest Gulf behind the front
will help swing winds back to southeast by Saturday. Decent
return flow on Sunday will pump moisture across the area to feed
into the next plains storm system. The weather will warm through
Thursday, with high temperatures well above normal, from the mid
80s to the lower 90s. A mild moderation will occur on Friday and
into the weekend with the Friday cold front, but overall
temperatures will still remain above normal.

MARINE:
Now through Tuesday: Winds at Buoy 42020 are now South at 14
knots with gusts up to 18 knots. However...seas remain around 7 to
9 feet. There is a line of storms moving across the Ranchlands
and Mid Rio Grade Valley early this morning. This line will move
towards the Laguna Madre and Lower Texas Coastal Water near
sunrise and storms will likely continue over the Gulf waters
through much of the afternoon This storms will produce frequent
lightning and strong winds...possibly near gale force...and
locally higher seas.

Meanwhile...winds are expected to decreases and shift to the
northwest later today as the weak surface low moves across the Rio
Grande Plains. Improved marine conditions will return later this
evening. However...a strengthening pressure gradient will be noted
on Tuesday and northwest winds will become elevated again.

Tuesday night through Friday night: Winds will remain north
through Wednesday as high pressure spreads over the area. Winds
will begin to swing or veer Wednesday night, becoming south on
Thursday with low to moderate seas. Winds will pick up slightly
Thursday night, with a modest increase in seas, with possible
small craft should exercise caution conditions, due to the low
pressure associated with a plains storm system, before turning to
north and northwest with the arrival of a weak front on Friday.

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...Small Craft Advisory until 6 AM CST early this morning for
     GMZ150-155-170-175.

&&

$$

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