Area Forecast Discussion
Issued by NWS Brownsville, TX
FXUS64 KBRO 211756
Area Forecast Discussion
National Weather Service BROWNSVILLE TX
1256 PM CDT SAT MAY 21 2016
.DISCUSSION...Updated for latest aviation discussion below.
.AVIATION...Isolated showers will continue to develop along
the coastal counties this afternoon producing brief moderate
rain showers with possible lightning. TEMPO groups have been
included to this afternoon as the storms approach the terminal.
Low ceilings will be possible tonight to MVFR conditions across
the terminals with light se winds. Conditions begin to improve
into Sunday with gradient strengthening increasing SE winds.
.PREV DISCUSSION... /issued 703 AM CDT SAT MAY 21 2016/
DISCUSSION...Updated for latest aviation discussion below.
AVIATION...IR satl imagery shows patchy sc decks advecting from
south to north over the western and central portions of Deep South
TX early this morning. Daytime heating after sunrise will likely
mix any lingering low ceilings back to vfr levels throughout the
daylight hours. Daytime heating may interact with lingering
elevated CAPE values to fire some isold conv later this afternoon
into the early evening hours. However the coverage will not likely
be enough to warrant a mention of this in the current taf
issuance. Low ceilings will be a possibility once again late in
the taf period possibly resulting in another round of mvfr/ifr
PREV DISCUSSION... /issued 419 AM CDT SAT MAY 21 2016/
SHORT TERM (Today through Sunday): At the surface...the old
stationary front is meandering across the northwestern Gulf of
Mexico and across Deep South TX. This old front will likely
dissipate later today or tonight allowing a southeasterly low level
flow to return to the region. Further aloft 500 mb ridging will
build steadily over the area allowing a more subsident airmass to
prevail as the deep layer rh values diminish over the region. The
00z BRO sounding showed a pretty elevated MUCAPE of 4426 j/kg with a
pwat near 2 inches. So expect that it will take some time for these
values to diminish this weekend. KBRO radar echoes this morning
indicates that the CAPE and deep layer moisture levels haven`t
dropped off much today with plenty of light returns evident to our
north and down to the southeast. The latest numerical guidance
from the NAM/GFS and ECMWF all indicate that some mention of at
least some slgt chc pops will be needed both for today and Sunday
as daytime heating effects may fire off a little bit of conv.
As the 500 mb ridge axis builds over the region expect the daytime
to increase a bit for both Sat and Sunday. The latest MET temp
guidance is a bit cooler versus both the MAV and ECMWF numbers. So
will go closer to the warm side of guidance due to the influence of
the 500 mb ridging.
LONG TERM (Sunday Night through Friday): 500mb ridging over
Texas will maintain generally hot and dry conditions across Deep
South Texas through midweek. Rain chances begin to increase by
late week as the ridge moves east and southwest flow aloft
increases. Upper level impulses in the mid level flow combined
with increasing moisture will support isolated daytime or
overnight convection. Above normal daytime high and overnight low
temperatures can be expected through the forecast period.
MARINE: Now through Sunday...Surface ridging will prevail over the
western Gulf of Mex throughout the weekend which will allow
fairly benign marine conditions to continue. No SCA conditions
expected through Sunday with seas ranging from 2 to 3 feet.
Sunday night through Wednesday: Moderate winds and seas will prevail
along the Lower Texas Coast through the period with high pressure
over the western Gulf of Mexico. Periods of Small Craft Exercise
Caution and/or Small Craft Advisory conditions will develop Monday
through Wednesday as the pressure gradient begins to strengthen.
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