Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 100900

Area Forecast Discussion
National Weather Service Brownsville TX
400 AM CDT Tue Oct 10 2017

.SHORT TERM (Now through Wednesday): A mostly clear night for the
RGV overnight. Early this morning there have been a few widely
scattered showers across our adjacent offshore waters. These
showers have struggled a bit as they move onshore. Although
conditions are mostly tranquil at this time, things will begin to
gradually change later this morning.

A cold frontal boundary was located from the TX Big Bend region east
and northeast through the eastern Red River Valley. This frontal
boundary will continue to slide southward as the parent waves
continues it`s north and easterly progression into the lower
Missouri River Valley. Along and ahead of this front, showers and
thunderstorms are expected to develop by mid to late morning, first
across the northern Ranchlands, eventually dropping southward into
the lower valley.

Timing of the front and how much cloud cover we can get to develop
this morning will be everything in terms of high temperatures today.
We have gone the warmer route for the lower valley as we have been
sitting in some cases in the lower 80s much of the night with mostly
clear skies. Think some may even hit 90 across the south before
clouds and rain develop. Though, could be a few degrees cooler if
clouds/precip develop sooner.

Finally, behind the front more isentropic upglide type situation
occurs later tonight and into the morning hours. This should keep us
cloudy and damp in the southern Valley where the northern Ranchlands
should begin to dry out. By Wednesday think showers are possible,
especially along the coast and across adjacent GoMex waters.

Rainfall amounts will be heaviest in the southern valley today with
as much as an inch or two expected. Although no serious flooding is
currently anticipated, with PWATs above 2" think that some isolated
nuisance flooding can be expected, especially in poor drainage

.LONG TERM (Wednesday Night through Monday): Rain chances are
expected to linger across deep south Texas Wednesday night into
Thursday due to a weak coastal trough. Above normal temperatures
return Wednesday night and will continue through the rest of the
long term period. Mid level ridging will remain generally in place
into the weekend as high pressure spreads over the area. The ridge
will even build west as a slightly more zonal mid level pattern
develops. The coastal trough weakens and dissipate by Thursday with
winds veering to the east Thursday night and southeast by the
weekend. The return flow will support low end rain chances in the
coastal areas Friday and through the weekend. Both the GFS and ECMWF
suggest another cold front will push through the area on Monday.


.MARINE (Now through Wednesday): Southerly flow will give way to
moderate northeast winds later today as a cold frontal boundary
continues to push southward through the region. In fact, winds
will be around or slightly about 20 kts for much of the marine
areas this afternoon and into the evening. Because of this did go
ahead and hoist a Small Craft Advisory for all marine zones this
afternoon and evening. Showers and perhaps a few thunderstorms
will be likely as the frontal boundary nears.

With the increasing northeast flow, wave heights will increase
offshore to 6` perhaps a tad more as wind really begins to increase
behind the frontal boundary. Winds will remain elevated through much
of Wednesday as pressure gradient remains tight between the coastal
trough to our southeast and the Canadian high pressure across the
Missouri Ozarks. With the continued moderate winds, small craft are
urged to exercise caution in adjacent waters. Off and on showers
(and perhaps a storm?) can be expected through midweek.

Wednesday Night through Saturday night: Elevated winds and seas may
linger into Wednesday night resulting in exercise caution conditions
initially. Marine conditions will quickly improve on Thursday as
northeast winds gradually veer to the east and become light as high
pressure spreads over the area and shifts east. Light southeast
winds will return Friday night into the weekend as high pressure
pushes out over the Gulf. Moderate northeast winds and building
seas develop on Monday with the passage of another cold front.


BAYVIEW/PORT ISABEL  87  70  81  72 /  80  60  50  50
BROWNSVILLE          90  67  80  71 /  80  60  50  50
HARLINGEN            90  67  79  70 /  80  50  40  50
MCALLEN              91  66  78  70 /  70  50  40  20
RIO GRANDE CITY      85  65  78  68 /  70  40  30  10
SOUTH PADRE ISLAND   86  73  81  75 /  80  70  50  50


GM...Small Craft Advisory for winds from 1 PM this afternoon to 7 PM
     CDT this evening for GMZ130-132-135.

     Small Craft Advisory from noon today to 10 PM CDT this evening
     for GMZ150-155-170-175.



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