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FXUS64 KHGX 190042

Area Forecast Discussion
National Weather Service Houston/Galveston TX
742 PM CDT Thu Oct 18 2018



OVC skies are still affecting the majority of the TAF sites, with
little to no rain activity. MVFR ceilings are expected to linger
overnight. Moisture advection and an increase in shower activity
is expected during the forecast period...particularly across the
coastal areas. For tonight and tomorrow, periods of SHRA can be
expected across GLS/LBX and periods of -RA can be expected across
the rest of the TAF sites. SFC winds will continue to shift more
easterly but veer back to the north tomorrow night.


.PREV DISCUSSION... /ISSUED 347 PM CDT Thu Oct 18 2018/

SHORT TERM [Tonight through Friday]...
Frontal boundary remains stalled off the coast in the far offshore
Upper Texas Coastal waters. Moisture continues to increase south
of the boundary where the majority of shower and thunderstorm
activity exists this afternoon. There is still some warm advection
over the front with isentropic lift which is why cloud cover has
not quite eroded as previously thought. There have still been some
breaks in the clouds but not near as much as there could be.

Going forward tonight there should be an increase in moisture and
with that showers and thunderstorms. Most of the activity should be
confined to the coast and areas SW of Houston. Beyond that more
activity can be expected over central Texas where they do not need
more rainfall. These trends should continue into Friday with a
gradual spreading of rain/showers and isolated thunderstorms for
tomorrow. Short term guidance really do not hit any one area with
shower and thunderstorm activity. The main forcing will be
isentropic lift and the release of any elevated instability. There
should be a good gradient in temperatures with upper 60s for the
Brazos Valley and maybe near 80F along the coast for high


LONG TERM [Saturday Through Thursday]...
Coastal trof may edge a few miles inland late Friday and Friday
night bringing a chance of convection to portions of the
area...generally along & south of I-10.

Another cold front will make its way into the region and off the
coast Saturday. There will still be some resident moisture across
the region to work with, but lack of convergence along the front
(winds will already be n/ne) should keep overall coverage and
impact in check. Drier llvl airmass will filter in late Sat and
Sunday and should allow for a rain-free 24 to 36 hours. There
should still be considerable mid/high cloudiness however.

Rain chances will increase again Monday and persist into midweek.
Look for another coastal trof to develop as high pressure behind
Saturday`s moves eastward. This and a SW flow aloft re-establishing
itself should make for a fairly wet first half of the week.  47

Small craft advisory will continue overnight but winds and seas
should slowly decrease Friday morning and through the rest of the
day tomorrow. Winds and seas decrease more into Saturday ahead of
a cold front. Winds behind the front should increase from the
north mainly late Saturday afternoon into Sunday. More small craft
advisories will be needed behind the front.

The other concern tonight will be coastal flooding. Northeast to
east winds have kept tide levels elevated and seas are still rolling
in at rough levels. High tides tonight could reach 3.5 feet or
higher MLLW along Gulf facing beaches of Bolivar Peninsula and
Galveston Island. There could be some minor impacts with wave run up
on Highway 87 for Bolivar and low lying areas on Galveston Island.
Coastal flood advisory has been issued to cover the potential for
these impacts. Coastal flooding if any should be confined to these



College Station (CLL)      58  69  58  69  56 /  40  50  50  30  10
Houston (IAH)              62  78  64  74  60 /  20  40  40  30  10
Galveston (GLS)            73  80  72  78  66 /  40  50  50  30  20


TX...Coastal Flood Advisory until 1 PM CDT Friday for the following
     zones: Galveston Island and Bolivar Peninsula.

     the following zones: Galveston Bay...Matagorda Bay.

     Small Craft Advisory until 4 AM CDT Friday for the following
     zones: Coastal waters from Freeport to Matagorda Ship
     Channel TX out 20 NM...Coastal waters from High Island to
     Freeport TX out 20 NM...Waters from Freeport to Matagorda
     Ship Channel TX from 20 to 60 NM...Waters from High Island
     to Freeport TX from 20 to 60 NM.




NWS HGX Office Area Forecast Discussion