235 
FXUS64 KBRO 080009 AAA
AFDBRO

Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
609 PM CST Thu Mar 7 2019

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

&&

.AVIATION...The low level flow across the RGV has shifted around
from the E-SE today which is increasing the WAA and moisture
advection over the region. Currently the ceilings across the RGV
remain in general MVFR/VFR levels. As the surface flow decreases
later tonight and the nocturnal inversion strengthens up, expect
the ceilings will drop down into IFR levels through sunrise Fri.
The increasing daytime heating and the increasing low level mixing
will then return the ceilings back to MVFR/VFR levels. 

&&

.PREV DISCUSSION... /issued 244 PM CST Thu Mar 7 2019/ 

SHORT TERM (Tonight through Friday Night): Zonal flow through 
the short term, with a 500 mb trough swinging across north Texas 
Friday night into Saturday. Thicknesses will increase through 
Saturday, supporting warming, above average temperatures. Friday 
will be in the 80s. Otherwise, there will be morning low clouds 
turning into a mix of clouds and sun Friday with moderate to 
breezy southeast winds. Patchy coastal marine fog may spread 
inland tonight and Friday night.

LONG TERM (Saturday through Thursday): A series of midlevel
troughs will rotate across the western US, providing progressive
weather systems across the US. The first in the series of troughs
will be ejecting NEWD across the central US on Saturday morning,
only slightly clipping south Texas. While an associated cold front
will stay well to the north Saturday, it will be able to nudge the
dryline toward the western valley.This will help temperatures jump
considerably, with highs reaching into the low to mid 90s, which
would set records for both BRO (90 in 2006) and MFE (91 in 2011).
As the trough departs, weak ridging sets up across the Gulf as a 
larger trough spins just off the west coast. Southeast surface 
flow will return Sunday and Monday, holding back temperatures into
the 80s, but bringing back the humidity. The leading edge of the 
trough sweeps NEWD across Texas late Tuesday into WEdnesday, which
will be far enough south and east to drag a cold front through 
Wednesday morning. Upper level support, along with llvl moisture, 
will help spark some shower and thunderstorm activity Tuesday 
during peak heating, and again late Tuesday night into Wednesday 
near the front. 

MARINE:
Through Friday night: Light to moderate southeast winds tonight
and Friday, with a slight uptick in winds and seas late Friday
night due to a tighter gradient between Gulf high pressure and
Plains storm system lower pressure. Exercise caution to low end
small craft advisory conditions will be possible. Marine fog will
be possible along the coast the next two nights.

Saturday through Tuesday: The weak surface trough/dryline will
move into the central valley Saturday, allowing marine winds to
decrease to 5 to 10 knots through the day. This allows seas to
relax to around 2 feet. Modest southeast flow continue Sunday and
Monday before winds finally increase Tuesday with the approach of
the next front. Breezy conditions may be enough to kick Gulf
swells up to 6 or 7 feet, so some advisories may be needed for the
open Gulf waters during the day.

&&

.BRO WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&

$$

This product is also available on the web at:
HTTP://WEATHER.GOV/RGV

Short Term/Aviation...60
Long Term...65
Graphicast/Upper Air...69