Area Forecast Discussion
Issued by NWS Houston/Galveston, TX

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894
FXUS64 KHGX 210448
AFDHGX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1148 PM CDT Sun Oct 20 2019

.AVIATION...
Still looking for MVFR ceiling development overnight ahead of the cold
front. Latest timing of the front and associated north wind shift looks
like CLL area 09Z-12Z, IAH area 12Z-15Z and GLS area 14Z-17Z. Line of
SHRA with embedded strong/severe TSRA has developed along and ahead
of the front in Central Texas, and expect to see gusty winds, brief
heavy downpours and possible IFR ceilings with this line as it moves
across the area. Improving conditions can be expected from N to S
as the day progresses with skies eventually becoming clear.  42
&&

PREV DISCUSSION... /ISSUED 353 PM CDT Sun Oct 20 2019/

DISCUSSION...

SHORT TERM [Through Monday]...
Hires models continue to point to the possibility of some iso/sct
late afternoon or early evening precip. Expect anything that does
develop to dissipate around or slightly after sunset. Otherwise, the
majority of the night should remain fairly quiet with some stratus
developing. Winds should remain up enough whereas fog shouldn`t be a
concern.

As we approach sunrise, however, look for a line of showers and
tstms to be moving in from north Tx and across se Tx during the
morning hours. There is some uncertainty in regards to timing, as
some of the guidance wants to slow the front down south of the
Highway 59/69 corridor during the day tomorrow. But considering the
southward push into the region occurring during the overnight hours
and expected cold pool behind it with the precip, have trended the
fcst more heavily weighted with the faster solns (Tx Tech WRF, ARW,
NMM and ECMWF).

Expect the line of precip to be on a gradual weakening trend (severe
wx-wise) as it continues its southward push thru the area with the
better forcing/dynamics situated n/ne of the area. Though can`t rule
out a few embedded stronger storms, the general expectation would be
for some 25-45mph gusts and brief heavy downpours along the leading
edge. Improving conditions and clearing is expected a few hours
behind the front. 47

LONG TERM [Tuesday Through Sunday]...
Expect a cool down behind the front Monday, with high temperatures
for a majority of the week peaking in the 70s to low 80s. Low
temperatures will also take a tumble, falling into the upper 40s
to 60s across much of the region. Conditions should remain dry
through the middle part of the week, with the next best chance
for precipitation not returning until Thursday. Onshore flow
strengthens and advects in moisture by Thursday morning, and
showers and thunderstorms should spread from west to east across
much of Southeast Texas throughout the day. There should be better
coverage of precipitation along and south of I-10 Thursday.
Precipitable water values should once again rise to near 1.7-1.9
inches, in addition to a short wave embedded in the upper level
flow that shifts from west to east across the region. Therefore,
expect thunderstorms to produce frequent lightning, gusty winds in
and around stronger storms, and brief heavy downpours.

In the far extended, another cold front moves into the picture,
but there still remains some uncertainty in the details regarding
the strength and timing of this feature. In the latest global
guidance, the GFS remains the most progressive, and pushes the
front through rather quickly with the boundary reaching the coast
by late Thursday evening. The GFS is followed by the Canadian and
ECMWF solutions, which lag behind by about 6 to 9 hours. This
front looks to be stronger than the one anticipated for tomorrow,
and could drop temperatures as low as the mid 40s to upper 50s
during the overnight hours. High pressure should build back in
behind this frontal passage, leaving dry conditions for most of
the weekend.

MARINE...
Small craft should continue to exercise caution through the
overnight hours as onshore flow strengthens. The chance for
showers and thunderstorms will increase tonight and Monday out
ahead of our next frontal passage which should reach the coast by
Monday afternoon and push through the Gulf waters by evening
hours. Winds will increase to 15 to 25 knots behind the front, out
of the north to northeast and Small Craft Advisories will likely
be warranted. Light to moderate southwesterly flow should prevail
for most of next week. Our next front should arrive late in the
week.

Additionally, a Coastal Flood Statement remains in effect for the
Gulf facing beaches through Monday morning to account for minor
coastal flooding around times of high tide. Water levels should
peak around 3.7 feet MLLW. The more susceptible locations that
could see the minor flooding will be along the Bolivar Peninsula,
Jamaica Beach, Blue Water Highway and Surfside Beach.

Hathaway

FIRE WEATHER...
Clearing skies and falling dewpoints behind the passing cold front
Monday morning will lead to RH`s bottoming out around 30% north and
west of the Highway 59 corridor Monday afternoon. However, rainfall
earlier in the day should mitigate most fire weather concerns. 47

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      67  77  50  79  49 /  90  40  10   0   0
Houston (IAH)              73  80  55  77  53 /  30  90  10   0   0
Galveston (GLS)            75  80  66  77  68 /  50  90  30   0   0

&&

.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION until 8 AM CDT Monday 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...Galveston Bay...
     Matagorda Bay...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.

&&

$$



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