Area Forecast Discussion
Issued by NWS Brownsville, TX

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FXUS64 KBRO 230901

Area Forecast Discussion
National Weather Service BROWNSVILLE TX
401 AM CDT Sun Oct 23 2016

.SHORT TERM (Today through Monday): Models in good agreement with
a weak shortwave trough moving through Texas today into Monday as
mid- ridge continues to move east. Moisture will be increasing
above 500mb as well as below 850mb but the airmass between these
levels remains dry. Both GFS and ECMWF show a lead vorticity axis
moving through the state in conjunction with the trough however
weak diffluent flow and very limit lift is produced by this
disturbance. Little to no precipitation is produced by the 00Z
model output for today or tomorrow. Will continue to show silent
10 pops for today and tonight and have taken out the rain for
Monday with less overall moisture with the upper trough moving
northeast of the CWA. Overall for the sensible weather, we can
expect a mostly cloudy to cloudy day as high clouds thicken and
lower in advance of the trough and an increase in lower clouds as
the Gulf moisture spreads inland. Monday starts out on the cloudy
side with more sunshine later in the day as the disturbance passes
to the east. Can not rule out a possible sprinkle or two falling
out of the thickening cirrus but no accumulating precipiation is

Temperatures have rebounded 5 to 12 degrees from this time
yesterday as gulf moisture increases and thicker high clouds
spread overhead. Highs today will be similar to possibly a few
degrees warmer then yesterday. Model guidance shows warmer
readings in the East over the West as does the current forecast
due to thicker cloud cover limiting insolation. Overnight lows
will be a few degrees warmer as dew points increase with the
return of southeast winds and Monday`s highs climb slightly above
normal as more sunshine peaks through the clouds.

LONG TERM (Monday night through Saturday): At the beginning of the
long term, H5 ridging will be over the High Plains with a weak
embedded trough moving over East Texas. High pressure will extend
over the Gulf Coast states into the North Gulf and East Texas. Light
to moderate east southeast winds will allow for morning coastal
showers and then an afternoon sea breeze with high temperatures in
the mid to upper 80s. Not much change is expected through Wednesday
with overnight low temperatures from the mid 60s to the lower 70s
with a repeat of Tuesday weather during the day.

By Wednesday night into Thursday, mid level ridging will reposition
to the West, over the Rockies, allowing a reestablished high height
center over the Southwest to start building over West Texas. Drier
air will also spill south over the Plains from Canada, but won`t
reach this far south. Meanwhile, the Gulf will experience increased
convective activity in general, with lwr heights overhead. It seems
as though persistent lower pressure over the Southwest Gulf may also
play a role in the wider qpf coverage. Winds will tend to back just
slightly, to east or east northeast at this time. The Gulf waters
and coastal areas will never really escape at least some pop shading
in the forecast through the long term. Even on Friday and Saturday,
with ridging starting to extend farther east over East Tx, coastal
shwrs with poss penetration into the Mid Valley will be possible.

In summary, upstream ridging will block any serious weather threat
from the West, while activity over the Gulf will be more inclined to
show up on the doorstep as Gulf based shower activity or diurnal sea
breeze activity. Without a strong focusing mechanism or even lift,
rainfall amnts, if any, will remain fairly light. Temperatures will
be around five to ten degrees warmer than normal.


Today through Monday...Surface high pressure moves east across
the Southeast states eventually expanding across the Northern Gulf
waters. A weak upper level low pressure trough moves into West
Texas today and cross the state Monday. The two pressure systems
will combine providing a light to moderate southeast to east wind
and a low to moderate sea. A spotty shower can not be ruled out

Monday night through Thursday...A broad ridge axis will extend
vertically over the High Plains, with a weak trough exiting over
East Texas. High pressure over the Gulf Coast states will also
control the North Gulf waters. This will support light to moderate
east to southeast winds and low to moderate seas. The South Gulf
will be somewhat more active weather wise, with showers and even
thunderstorms moving up from the Southwest into the lower Texas
coastal waters on a regular basis. As upstream mid level ridging
builds over Texas, and perhaps with the help of lower pressure
over the Southwest Gulf, winds may back to east or northeast on
Thursday. Wave heights offshore may be enough for exercise caution
conditions Thursday night.


BAYVIEW/PORT ISABEL  85  73  87  72 /  10  10  10  20
BROWNSVILLE          86  72  87  71 /  10  10  10  20
HARLINGEN            87  69  89  68 /  10  10  10  10
MCALLEN              88  70  91  69 /  10  10  10  10
RIO GRANDE CITY      86  68  88  68 /  10  10  10  10
SOUTH PADRE ISLAND   83  78  84  75 /  10  10  10  20




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