Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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000
FXUS64 KHGX 180439
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1139 PM CDT Mon Jul 17 2017

.AVIATION...
Cirrus dissipating with some patchy MVFR CIGS dotting the area.
Expect some patchy MVFR fog at the outlying sites and confident
enough at CXO/SGR/LBX to mention. May see a few showers develop
near the coast and as far inland as the Interstate 10 corridor
after 3 am and will need to monitor this for updates.

Profiles remain moist and unstable during the afternoon and
confidence remains high that scattered storms will develop across
the area mainly during the late morning and afternoon hours
tapering off by mid evening over the north.
45

&&

.PREV DISCUSSION... /ISSUED 934 PM CDT Mon Jul 17 2017/

DISCUSSION...
Radar has quieted down across SE TX this evening...even over the
coastal waters. However will be expecting development to begin a-
new overnight (as it has been the trend of late). Forecast looks
on track so no changes planned with this update. 41

PREV DISCUSSION...  /ISSUED 356 PM CDT Mon Jul 17 2017/

Showers and thunderstorms moving in from the east and then dying
out as they cross over the region. A cluster of thunderstorm
activity moving out of Hardin and Jefferson counties may hold
together and make it into southeastern Liberty County. Much of the
early day storm activity was focused south of the I-10
corridor... quickly becoming outflow dominant and blowing out
within 30 minutes or so. A partially cloudy day with many maximum
temperature readings reaching the lower 90s. Anticipating a quiet
overnight...partially cloudy with central and southern county
20-30% rain chances for pockets of late afternoon into early
evening isolated cell behavior. Rural open expanse near sunrise
light shallow fog with temperatures in the interior middle
70s...coastal upper 70s to around 80 F at the shoreline.

The synoptic pattern remains one of Central U.S. upper ridging
that will slowly expand down into the eastern Texas past mid-week.
No change in the recent thermo and moisture profiles over eastern
Texas. Weak disturbances moving in from the east (northern Gulf)
over the next couple of days will travel across southeastern Texas
within a generally benign mid to upper cyclonic flow regime.
Timing of this slightly higher PVA/Omega will determine if any
lift provided by these elements will be enhanced by daytime
heating. Daily overnight rain chances remain low with relatively
higher POPS focused along coast and over the local bays and
nearshore Gulf waters. Inland rain chances will remain in the 30
to 50% range with many not receiving much precipitation (if any at
all) while others in the path of discrete thunderstorms pick up a
quick 1 to 2 inches. In other words...this typical summertime
pattern will persist over the next several days.

There is subtle change in the extended period (next weekend into
early next week) that involves the positioning of the upper ridge.
This morning`s GFS members want to push the center of the ridge
east into the Appalachian Mountains with it expanding down into
Florida from Friday into Saturday. The overall expansion of higher
heights will also envelope eastern Texas/Louisiana and provide a
bit more subsidence to the region. Drier air will begin to advect
in from the Gulf early next week...1.6 inches instead of around 2
inch pwats. This should lead to a general downtrend in day-to-day
convective coverage and increase afternoon warmth...average mid
90s/mid 70s. Moisture levels should be low enough to keep heat
indices in the 103 to 106 F range but this will likely need to be
monitored for possible excessive heat issues by this time next
week. 31

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      75  94  75  95  76 /  50  20  10  20  10
Houston (IAH)              76  92  77  93  77 /  20  40  10  40  10
Galveston (GLS)            81  87  81  88  82 /  30  40  20  40  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&

$$

Discussion...41
Aviation/Marine...45



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