Flash Flood Warning 16, NWS Houston/Galveston, TX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
424 AM CDT Sun Jun 4 2017

.DISCUSSION...
At 3 AM, strong convection continues to develop over the northern
half of the CWA with another line of developing storms near the
coast. Rainfall intensity has begun to increase and rainfall
totals since midnight are between 1.5 and 2.5 inches across
Burleson, Brazos, Grimes and Walker counties. There is a trough of
low pressure or remnant outflow boundary that extends across east
central Texas down into south central Texas and this feature
appears to be the focus for tonight's activity. Short term
guidance pushes this area east and focuses much of the
precipitation along the coast this morning and offshore this
afternoon. Subsidence in the wake of this system could leave much
of SE TX dry for the late morning/early afternoon until
heating triggers additional shra/tsra late this afternoon and
evening. Convective temperatures today are low, roughly between
81 and 83 degrees. Think most areas will receive rain at some
point today so will go with likely PoPs. The upper trough
currently over West Texas will slide east tonight. SE TX looks to
be in a favorable position for rain later tonight into early
Monday but PW values drop to around 1.70 inches. Will maintain
high end chance PoPs for now. Storm motion progged to be a bit
faster than previously thought and motion today should be between
10 knots and around 5 to 10 knots on Monday.

Models are trending much drier on Monday. PW values for much of
the day are between 1.5 and 1.6 inches before increasing to 1.90
inches between 18-21z. Convective temps are around 84 degrees so
daytime heating should again trigger afternoon convection. The
upper level trough axis will push east of the region Monday night.
Not really seeing a trigger but the proximity of the upper trough,
a weak cold front and PW values near 1.70 inches is enough to
maintain rain chances.

Still not liking rain chances on Tuesday since SE TX will lie on
the west side of the upper trough and a weak cold front will have
already crossed the region but both the GFS and ECMWF bring a weak
vort lobe south on the backside of the departing trough.
Convective temps are in the mid 80s and there might be enough
heating coupled with the vort to generate some storms on Tuesday
afternoon. Fcst soundings actually show a bit of instability with
CAPE over 3000 and an inverted V beneath 850 mb.

Conditions improve Wed-Sat with drier air working into SE TX. A
large diurnal range in temperatures can be expected. Sfc dew
points could be in the 50s over parts of the area on Thursday. The
latter half of the week should feature dry cool mornings and warm
and not so humid afternoons. Moisture make a rapid return Friday
night into Saturday with dew points back into the lower 70s by
Saturday night. 850 temps warm over the weekend as well with sfc
high temps back into the lower 90s. 43

&&

.MARINE...
An upper low over the Southern Plains will keep good chances for
showers and thunderstorms over the marine areas today and Monday.
Long period swells of 3 to 5 feet over the offshore waters are
expected today. Otherwise, for the most part light to moderate winds
are expected; although, stronger winds and elevated seas will be
possible in thunderstorms today and again on Monday. A frontal
boundary is then expected to move off of the coast and swing the
onshore winds around to offshore Monday night or Tuesday morning. A
northeasterly wind flow pattern is then expected to set up during
the mid week period with onshore winds finally returning by around
late Thursday. Winds are not expected to reach caution or advisory
criteria during the mid or late week period.

40

&&

&&

.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL)      87  71  86  71  88 /  60  50  60  30  20
Houston (IAH)              88  73  88  72  88 /  60  50  60  40  40
Galveston (GLS)            86  77  86  79  88 /  60  50  60  40  40

&&

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

Hazardous Weather Outlook
National Weather Service Houston/Galveston TX
347 PM CDT Sat Jun 3 2017

TXZ163-164-176-177-195>198-042100-
Brazos-Burleson-Grimes-Houston-Madison-Trinity-Walker-Washington-
347 PM CDT Sat Jun 3 2017

This hazardous weather outlook is for portions of Southeast Texas..

.DAY ONE...Tonight

Daytime heating will trigger scattered showers and thunderstorms
late this afternoon and evening.  Storm motion will be slow and
locally heavy rain will be possible in the stronger storms.

.DAYS TWO THROUGH SEVEN...Sunday through Saturday

An upper level low will trigger scattered to numerous showers and
thunderstorms Sunday and Monday. Storm motion will remain slow
and locally heavy rain will be possible. Some flooding issues
might be possible both Sunday and Monday. Widespread rainfall by
Monday night will be between 1 and 3 inches with isolated areas
receiving up to 4 inches of rain.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.

GMZ330-335-350-355-370-375-042100-
Coastal waters from Freeport to the Matagorda Ship Channel out
20 NM-Coastal waters from High Island to Freeport out 20 NM-
Galveston Bay-Matagorda Bay-
Waters from Freeport to the Matagorda Ship Channel from 20 to
60 NM-Waters from High Island to Freeport from 20 to 60 NM-
347 PM CDT Sat Jun 3 2017

This hazardous weather outlook is for portions of Southeast Texas..

.DAY ONE...Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Sunday through Saturday

Swells propagating into the coastal waters will produce wave
heights near or just above 5 feet in the offshore waters.
Mariners should prepare for locally rough seas due to the swells
and also from thunderstorms producing variable and gusty winds and
frequent lightning.

Waterspouts may be possible Sunday morning.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.

TXZ178-179-199-200-210>214-226-227-235>238-042100-
Austin-Brazoria-Chambers-Colorado-Fort Bend-Galveston-Harris-
Jackson-Liberty-Matagorda-Montgomery-Polk-San Jacinto-Waller-
Wharton-
347 PM CDT Sat Jun 3 2017

This hazardous weather outlook is for portions of Southeast Texas..

.DAY ONE...Tonight

Daytime heating will trigger scattered showers and thunderstorms
today. Storm motion will be slow and locally heavy rain will be
possible in the stronger storms.

.DAYS TWO THROUGH SEVEN...Sunday through Saturday

An upper level low will trigger scattered to numerous showers and
thunderstorms Sunday and Monday. Storm motion will remain slow
and locally heavy rain will be possible. Some flooding issues
might be possible both Sunday and Monday. Funnel clouds may be
possible Sunday morning with the rapid development of showers and
thunderstorms. Widespread rainfall by Monday night will be between
1 and 3 inches with isolated areas receiving up to 4 inches of
rain.
.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.

Special Weather Statement
National Weather Service Houston/Galveston TX
114 AM CDT SUN JUN 4 2017

TXZ195>198-040645-
Brazos TX-Washington TX-Grimes TX-Burleson TX-
114 AM CDT SUN JUN 4 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN BURLESON...NORTHERN
GRIMES...NORTHEASTERN WASHINGTON AND BRAZOS COUNTIES UNTIL 145 AM
CDT...

At 113 AM CDT, Doppler radar was tracking a strong thunderstorm 9
miles southwest of Millican, or 14 miles west of Navasota, moving
northeast at 35 mph.

Winds in excess of 40 mph will be possible with this storm.

Locations impacted include...
College Station, Bryan, Navasota, Washington, Somerville, Snook,
Kurten, Wixon Valley, Millican, Lake Somerville Dam, Kyle Field,
Independence, Wellborn, Roans Prairie and Carlos.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

If on or near Lake Somerville, get out of the water and move indoors
or inside a vehicle. Remember, lightning can strike out to 10 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.

&&

LAT...LON 3074 9647 3087 9639 3065 9588 3021 9624
      3032 9656
TIME...MOT...LOC 0613Z 209DEG 28KT 3038 9633

40

Special Weather Statement
National Weather Service Houston/Galveston TX
148 AM CDT SUN JUN 4 2017

TXZ176-195>198-040715-
Madison TX-Brazos TX-Washington TX-Grimes TX-Burleson TX-
148 AM CDT SUN JUN 4 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN BURLESON...GRIMES...
NORTHEASTERN WASHINGTON...SOUTHEASTERN BRAZOS...NORTHWESTERN
MONTGOMERY...SOUTH CENTRAL MADISON AND SOUTHWESTERN WALKER COUNTIES
UNTIL 215 AM CDT...

At 147 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 11 miles east of College Station to near
Washington. Movement was northeast at 40 mph.

Winds in excess of 40 mph will be possible with these storms.

Locations impacted include...
Eastern College Station, Navasota, Washington, Bedias, Millican,
Anderson, Iola, Roans Prairie, Richards and Carlos.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3095 9588 3063 9583 3049 9582 3043 9583
      3031 9617 3036 9632 3063 9627
TIME...MOT...LOC 0647Z 229DEG 33KT 3066 9613 3037 9619

40

Special Weather Statement
National Weather Service Houston/Galveston TX
327 AM CDT SUN JUN 4 2017

TXZ195-196-040915-
Brazos TX-Burleson TX-
327 AM CDT SUN JUN 4 2017

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL BURLESON AND WEST CENTRAL
BRAZOS COUNTIES UNTIL 415 AM CDT...

At 326 AM CDT, Doppler radar was tracking a strong thunderstorm near
Caldwell, moving northeast at 25 mph.

Pea size hail and winds in excess of 35 mph will be possible with
this storm.

Locations impacted include...
College Station, Bryan, Caldwell, Snook, Kyle Field, Chriesman and
Wellborn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3073 9662 3073 9660 3071 9660 3070 9656
      3074 9646 3081 9642 3055 9623 3042 9684
      3048 9690 3049 9690 3054 9692 3056 9696
TIME...MOT...LOC 0826Z 234DEG 22KT 3060 9671

Special Weather Statement
National Weather Service Houston/Galveston TX
424 AM CDT SUN JUN 4 2017

TXZ176-196-198-041000-
Madison TX-Brazos TX-Grimes TX-
424 AM CDT SUN JUN 4 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN GRIMES...
NORTHEASTERN BRAZOS AND SOUTHWESTERN MADISON COUNTIES UNTIL 500 AM
CDT...

At 424 AM CDT, Doppler radar was tracking a strong thunderstorm near
Kurten, or 8 miles east of Bryan, moving northeast at 15 mph.

Winds in excess of 40 mph will be possible with this storm.

Locations impacted include...
Northern College Station, northeastern Bryan, Kurten, Wixon Valley
and Iola.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3061 9627 3069 9636 3096 9622 3080 9594
TIME...MOT...LOC 0924Z 212DEG 14KT 3071 9623

40

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
450 AM CDT SUN JUN 04 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0215 AM     TSTM WND DMG     20 NNE NAVASOTA         30.66N  95.96W
06/04/2017                   GRIMES             TX   LAW ENFORCEMENT

            TREE DOWN BLOCKING A ROAD JUST NORTH OF SINGLETON NEAR
            HIGHWAY 90 AND FM 39

&&

EVENT NUMBER HGX1700274

CR