Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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FXUS64 KHGX 290451
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1151 PM CDT Wed Jun 28 2017

.AVIATION...
Very little change in forecast this cycle, as the focus continues
in the near term on potential for IFR/MVFR ceilings more inland,
and showers closer to the coast. Radar returns are nearing the
coastline, and even a -RA ob was reported at GLS, so VCSH was
bumped up to account for that in an amendment. Otherwise, look
for winds to drop off at all sites but GLS as winds decouple. VFR
conditions to return tomorrow once the early low ceilings lift,
with shower potential likely pinned pretty close to the coast.
Can`t totally rule out a quick shower at the Houston metro sites,
but at this time don`t think potential that far inland is even
high enough to merit a VCSH.

Luchs

&&

.PREV DISCUSSION... /ISSUED 725 PM CDT Wed Jun 28 2017/

DISCUSSION...
This evening`s forecast update can pretty much be summed up with
the latest water vapor imagery. Basically SE Texas lies in the
more subsident side of the shear axis with ascending motion to the
east in the Gulf and Louisiana. As such there have only a few
showers along the coast with most of the activity in the Gulf.
These trends should continue overnight into tomorrow morning but
the shear axis aloft should weaken some allowing for at least some
higher moisture to move back into the coastal areas for tomorrow.
Forecast will keep some rain chances but activity may be more
isolated to widely scattered. Really rain chances will continue to
decrease through the end of the week and into the Independence Day
weekend. The area could quite possibly go a solid week without any
rain chances which means summer time ridging aloft will rule. High
temperatures will get back into the mid 90s. We will need to
monitor heat index values over the weekend as low level moisture
may be high enough to support heat index values near 105F for the
area. With lots of people going outside for holiday activities, it
is a good time to remember to stay hydrated, check the back seat,
look before you lock and swim near lifeguards on the beaches. That
should serve as your PSA for the day.

Overpeck

PREV DISCUSSION... /ISSUED 626 PM CDT Wed Jun 28 2017/

AVIATION...
A couple tricky features overnight, with potential for low
ceilings, primarily north, and for light showers nearer the coast.
Do TEMPO some IFR ceilings at CLL and UTS, even going prevailing
for a short rate at CXO. Go with MVFR ceilings more coastward.

For showers, am real on the fence about how far inland to take any
potential streamer showers. For now, with winds looking to go
northeasterly late tonight into the early morning, have opted for
dry around the Houston metro, keeping VCSH only at LBX and GLS.
That may have to change if we get wraparound moisture from a low
pressure center over SW Louisiana.

Once we work past those features, we should see a return to VFR
for the rest of the period.

Luchs

PREV DISCUSSION... /ISSUED 317 PM CDT Wed Jun 28 2017/

DISCUSSION...
Showers and tstms have been fewer and farther between today as
deep drier air advances into southeast TX, and low level
convergence remains maximized well offshore. However will leave
chance PoPs near the coast this evening, especially near and east
of Galveston Bay, as a few showers may still rotate across this
area through sunset.

Expect showers and storms to remain in the forecast for a few
more days, before broad ssely low level flow becomes more
established and washes out some of these persistent surface
boundaries around the upper TX coast by Friday. Thus, will keep
scattered, mainly afternoon showers and tstms in the forecast
through the end of the week with a bit drier forecast into the
weekend. With lowering rain chances and clouds, expect temps to
nudge upwards with highs back to near normal for this time of year
in the lower to mid 90s by the weekend. Current models may be a
bit too cool with afternoon highs through the weekend and into the
4th of July, so have trended towards the warm side of the
guidance. Heat indicies will likely jump back into the lower to
mid 100s this weekend and hold through the middle of next week.

Evans

MARINE...
A moderate east flow will become south later tonight as a coastal
trough moves east. Low pressure will develop in the lee of the
Rockies on Thursday and onshore winds will strengthen in response
to this feature. A strong to moderate onshore flow will persist
Thursday night into Friday night as the low slowly moves east. The
pressure gradient will weaken over the weekend and winds/seas
will subside. Elevated tide levels will continue tonight but
should begin to subside on Thursday as the onshore flow become
more S-SW and the astronomical high tide decreases. After
coordinating with the Galveston Beach Patrol, will maintain the
Beach Hazard Statement for elevated tides and strong rip currents.
43

PREV DISCUSSION... /ISSUED 1240 PM CDT Wed Jun 28 2017/

AVIATION...
Daytime heating will trigger scattered showers and thunderstorms
but the air mass has begun to dry a little bit. Coverage is less
than the past few days. Light east winds will persist for the
afternoon and winds will decouple overnight. Could get some
showers near the coast late tonight and IFR/LIFR cigs possible
over the northern TAF sites late tonight. Convective temps are
warmer on Thursday so showers will likely develop later in the day
except near the immediate coast. 43

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      91  73  93  77  94 /  20  10  10  10  20
Houston (IAH)              89  74  92  78  93 /  50  20  30  10  40
Galveston (GLS)            83  79  88  82  89 /  70  30  50  10  40

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION until 5 AM CDT Thursday for
     the following zones: Waters from Freeport to the Matagorda
     Ship Channel from 20 to 60 NM...Waters from High Island to
     Freeport from 20 to 60 NM.

&&

$$

Discussion...39
Aviation/Marine...25


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