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Displaying AFOS PIL: AFDBRO Received: 2018-08-18 19:39 UTC

FXUS64 KBRO 181939

Area Forecast Discussion
National Weather Service Brownsville TX
239 PM CDT Sat Aug 18 2018

.SHORT TERM (Now through Sunday night): The H5 ridge remains 
centered over Arizona during the short term period, trying to 
extend eastward across southern Texas. This ridge will get pinched
during the day tomorrow by a weak inverted trough across the 
central Gulf and a trough dropping southeastward out of the 
Northern Rockies. This will decrease the strength of the ridging 
across Texas, and will allow slightly deeper Gulf moisture to push
westward up along the Gulf coast. Temperatures will remain in the
upper 90s and lower 100s, but the slight uptick in moisture will 
mean increased heat index readings of 107 to 111 during the 
afternoon Sunday. The trough to the north will also bring a weak 
cold front into north central Texas, which will tighten the 
gradient locally. This will result in a breezy day tomorrow, with 
winds approaching 20kts, with a few gusts of 25 to 30 possible 
during the afternoon hours. Moisture increase will not be enough 
to bring a chance of rain, but cloud cover will be a little more 
evident in the afternoon.

LONG TERM (Monday through Saturday): Overhead mid level ridging will 
retreat west slightly by Monday as a short wave trough moves out of 
the Rockies and into the Plains. A surface front will push south 
into central Texas on Monday, but will weaken enough to stall 
before it gets close to the CWA. As it does so, mid level ridging
will build back over the area. Thus, hot, sunny, and rain free 
weather should continue through Tuesday. While earlier forecasts 
may have picked up on rain signals, don't see much now. Guidance 
does improve rain chances a skosh for Tues and beyond, but even 
so barely matches climo. Thus, rain chances will remain low 
through much to most of the long term, but can't rule out isolated
sea breeze convection each afternoon. Temperatures will remain 
above normal through the period. High temperatures will range from
the lower 90s near the coast to the mid and upper 90s inland, to 
triple digits across the mid to upper valley under mostly sunny 
skies. Overnight low temps will generally be in the upper 70s to 
lower 80s. By Friday and Saturday a weak mid level low will 
detach from the larger scale flow and will set up over the lower 
Mississippi Valley. That weakness may continue south and southwest
toward the lower Texas coast on Sunday and Monday, but other than
a few showers, it's not clear whether there will be much more 


Now through Sunday night: Gulf winds have remained light today,
generally less than 10 knots, but winds across the Laguna Madre
have been steady in the 15 to 20 knot range. Mariners are advised
caution on the Laguna today until sunset when winds will decrease.
Lighter winds will continue for all areas overnight, allowing the
Laguna waters to relax and Gulf waters to remain 2 feet or less. A
breezier day expected for the Laguna Sunday as winds increase due
to a cold front in central Texas. Winds may reach sustained 20
knot level during the day, so mariners should be aware of possible
Small Craft Advisory conditions for the Laguna Madre. Gulf marine
conditions will remain more tranquil, with lighter winds of 10 
knots and swells remaining around 2 feet.

Monday through Thursday night: Light to moderate southeast to south 
winds and low to moderate seas will prevail as broad high pressure 
remains over the Gulf. Occasional isolated showers and thunderstorms 
will occur.


BAYVIEW/PORT ISABEL  80  95  80  93 /   0   0   0  10 
BROWNSVILLE          79  97  80  94 /   0   0   0  10 
HARLINGEN            78 100  79  97 /   0   0   0  10 
MCALLEN              79 102  80  99 /   0   0   0  10 
RIO GRANDE CITY      78 105  79 101 /   0   0   0  10 
SOUTH PADRE ISLAND   81  91  81  90 /  10   0   0  10 




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