Area Forecast Discussion
Issued by NWS Brownsville, TX
FXUS64 KBRO 261224 AAA
Area Forecast Discussion...UPDATED
National Weather Service BROWNSVILLE TX
724 AM CDT THU MAY 26 2016
.DISCUSSION...Updated for latest aviation discussion below.
.AVIATION...The BRO radar is pretty quiet this morning after the
conv that moved through the RGV late last night. Since the atms is
pretty worked over at this time do not expect any major conv to
develop until possibly later this afternoon and this evening after
the atms has had a chance to recover. So the MVFR ceilings will
likely steadily improve later this morning as the daytime heating
increases. Later in the current TAF period will include some
potential for conv through the afternoon and evening hours as the
atms destabilizes more. Will also reduce the ceilings back down to
.PREV DISCUSSION... /issued 422 AM CDT THU MAY 26 2016/
SHORT TERM (Today through Friday): The conv that impacted the RGV
earlier has died off. However more conv is firing over the northeast
portions of Mexico. The latest LAPS CAPE values shows that the atms
in place over RGV is currently worked over from the earlier conv.
However expect the atms to destabilize more later this afternoon.
The strong 500 mb closed now in place over desert southwestern
states will move east northeast reaching the the OK/TX Panhandle
area on Fri. 500 mb vortices moving around the base of the 500 mb
closed low will move over northern Mexico and southern Texas
throughout early Fri. The best moisture values look to pool over
Deep South TX through Thurs night with drier and more stable air
moving into the area later in the day Fri. Numerical guidance keeps
the best pops located over the northern half of the BRO cwa with
lower pops located over the southern half of the area which appears
to be located a little further away from the best 500 mb PVA. Will
maintain chc pops over most of the area today and tonight and will
then trend back pops a bit on Fri as the closed low moves further
north decreasing the PVA.
SPC maintains the RGV in the marginal risk area for both today and
Fri due to the impact of the sw closed mid level low. At this time
the overall confidence in the potential for svr wx is not the
greatest. Isold svr storms will be possible over mainly the northern
and western counties. However the exact timing of any svr storms
that form will be hard to pin down at this time.
Will warm up the high temps a bit for Fri as expect that there will
be a bit more sunshine which could edge them up some. Otherwise will
go close to persistence for max and min temps through Fri.
LONG TERM (Friday Night through Wednesday): persistent troughiness
at 500 mb over the western United States will battle with a 500 mb
ridge of high pressure that will try to build north over the Lone
Star State out of Mexico throughout the long term forecast period.
The mid-level flow over Deep South Texas and the Rio Grande Valley
will be from the southwest, and weak shortwaves riding within this
flow will produce isolated showers and thunderstorms across the
BRO CWFA. Since the majority of the convection will likely begin
over the neighboring high terrain of Mexico before advecting into
the official forecast area, sucessive shifts will need to monitor
for the potential of severe weather. Indeed, the Day 3 Convective
Outlook (sunrise Saturday to sunrise Sunday) produced by the Storm
Prediction Center already has a Marginal Risk of severe weather
for the entire BRO CWFA. Daytime high and overnight low temperatures
will prevail at above normal levels throughout the entire forecast
MARINE (Today through Friday): Buoy data off of the lower TX
coastline indicates that conditions have have pushed up close to
SCEC criteria as the PGF tightens up over the region in response to
the surface cyclogenesis occurring over the central plains states.
The winds and seas will likely push into SCA levels later tonight
with elevated winds and seas persisting into Fri.
Friday Night through Wednesday: an enhanced pressure gradient over
the western Gulf of Mexico will produce Small Craft Advisory winds
and/or seas from Friday night through Saturday night. As the center
of surface high pressure moves closer to the northwest Gulf of
Mexico, more moderate winds and seas are anticipated along the
Lower Texas Coast Sunday through Wednesday. Seas may be high enough
to warrant a Small Craft Exercise Caution for a portion of the Gulf
of Mexico waters east of Padre Island Sunday and Sunday night.
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