Area Forecast Discussion
Issued by NWS Brownsville, TX
FXUS64 KBRO 200927
Area Forecast Discussion
National Weather Service Brownsville TX
427 AM CDT Mon Mar 20 2017
.SHORT TERM (Today through Tuesday): High presssure at the surface and
aloft will maintain warm and dry conditions across Deep South Texas
through the short-term. Light winds and cooler temperatures have
allowed some fog to develop across portions of Brooks and Jim Hogg
counties this morning. The fog will lift and mix out by mid-morning
as winds begin to increase.
Very dry air (especially above 925 mb) will mix down today with
dewpoints away from the coast dropping into the 50s. The interaction
of surface high pressure over the Gulf and lower pressure across
west Texas will support breezy southeast today. High temperatures
today will be in upper 80s to lower 90s (except for the low to mid
80s near the coast) due to combination of abundant sunshine and a
drier airmass in place. Southeast winds will gradually diminish
after sunset this evening. Low temperatures tonight will be in the
60s across most of the area under partly cloudy skies. Patchy fog
will be possible again tonight across portions of the northern
ranchlands. Tuesday will be a repeat of today with plenty of
sunshine and high temperatures in the upper 80s to lower 90s across
much of the area. Breezy southeast winds will develop again on
Tuesday due to the tight pressure gradient.
.LONG TERM (Tuesday Night through Sunday): 500 mb ridging will
prevail over the RGV from Tues Night into Wed Night. A strong 500
mb closed low will then push across the south central Plains
states on Thurs and Fri. This will push a very weak cold front
through the region on Sat with little or now CAA expected Sat. A
SE flow will then quickly return Sat Night into Sun. Another 500
mb closed low will then move quickly in behind the first closed
low pushing over the central Plains states on Sun. Overall
moisture advection ahead of these 500 mb closed lows remain very
marginal through Sun. So will maintain only some slgt chc pops
with the passage of the closed low on Fri.
The PGF will be strongest on Thurs for the RGV ahead of the
surface low developing over the central Plains states. This will
result in breezy/windy conditions later in the week.
There is decent agreement between the GFS and the ECMWF in the
handling of this synoptic situation. The ECMWF is going with a
little warmer solution versus the GFS and prefer the ECMWF
solution for temps as believe that the cooler temps shown by the
GFS are a bit overdone.
.MARINE (Now through Tuesday): Buoy 42020 reported south-southeast
winds around 14 knots with gusts near 16 knots and seas of 3 feet
with a period of 7 seconds at 03 CDT/08 UTC. Small craft should
exercise caution on the Laguna Madre today and Tuesday due to
moderate winds. The pressure gradient will begin to tighten tonight
and Tuesday, which may allow winds to reach SCEC criteria on the
Gulf waters by Tuesday afternoon.
Tuesday Night through Friday Night: With the PGF strengthening due
to the approach of the 500 mb closed low and the associated
surface low the south to southeast low level flow will steadily
increase through the latter half of the week. The best chances for
SCA conditions will range from Thurs through Fri Night mainly for
the lower Texas Gulf waters.
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 84 68 84 69 / 0 0 0 0
BROWNSVILLE 87 67 87 68 / 0 0 0 0
HARLINGEN 90 65 90 68 / 0 0 0 0
MCALLEN 90 66 90 67 / 0 0 0 0
RIO GRANDE CITY 92 64 92 66 / 0 0 0 0
SOUTH PADRE ISLAND 79 70 79 70 / 0 0 0 0
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