Special Weather Statement, NWS Houston/Galveston, TX

Area Forecast Discussion
National Weather Service Houston/Galveston TX
1234 PM CDT Mon Jun 14 2021

.AVIATION [18Z TAF Issuance]...

Visible satellite shows a boundary developing west of the I-45
corridor. Resultingly, I have leaned towards convection occuring
along and west of this boundary. For our western/central sites
I have added in VCTS for the afternoon hours based on short-term
guidance (CLL, CXO, IAH, SGR, LBX). Winds are a mixed bag of
northerly and northeasterly with winds trending towards becoming
more easterly/southeasterly in the evening hours. The pressure
gradient weakens overnight leading to another night of light and
variable winds. Cloud cover will be more prevalent with a SCT to
BKN layer around 5,000 feet overnight. Winds pick up again Tuesday
morning with northerly to northeasterly winds around 5 to 7
knots. For Tuesday afternoon, expecting greater coverage of
thunderstorms with convection beginning around the 19z-20z
timeframe.

Batiste

&&

.PREV DISCUSSION /Issued 434 AM CDT Mon Jun 14 2021/...

.SHORT TERM [Today through Tomorrow/Tuesday Night]...

A strong overnight storm complex moving in from the NE did not make
much of an impact over inland portions of SE TX but does seem to be
keeping its momentum over the Gulf waters this morning. We'll like-
ly have to keep an eye on the leftover outflow boundaries from these
storms for this afternoon...along with the possibility of more very
warm heat index values. Light winds (as per the nearby surface high
pressure) may not help with the mixing out of the dewpoints as much
today (like yesterday) and with the seabreeze expected to move back
onshore, we could see a repeat of yesterday's temps (mid/upper 90s)
and HIs (102 to 106F) for today. (Of note for today, the new APTemp
algorithms are running hotter with the HI max ranges from 110F-114F
during the late afternoon.) At any rate, please take care if you're
outdoors for an extended period.

Some relief from the heat could come from isolated/scattered storms
developing this afternoon via the aforementioned outflow boundaries/
seabreeze. Look for brief heavy downpours and/or gusty winds should
activity gets going. Looking ahead, rain chances tomorrow may a bit
better as guidance is indicating a rather impressive speed max mov-
ing in from the north. But with other meso factors likely coming in
to play, will keep with mostly scattered POPs over the southern CWA
for now. Additionally, also kept both Max/Min temps a degree or two
higher than NBM on Tues. 41

.LONG TERM...

A broad upper level ridge of high pressure will be centered near
the 4 corners region on Wednesday. SE TX will lie on the eastern
edge of this feature and a series of upper level disturbances will
slide S-SW on the back side of the upper high bring the region a
chance of diurnally driven showers and thunderstorms. By Thursday,
the upper level ridge retreats a bit to the west and heights fall
a bit as an inverted upper trough begins to develop over the SW
Gulf of Mexico. Can't rule out a couple of stray showers on
Thursday but can't really find a trigger for precipitation as SE
TX is kind of between weather makers but daytime heating will
probably be sufficient to generate a few showers along the sea
breeze.

On Friday, an inverted upper trough of low pressure coupled with a
weak, broad and elongated area of low pressure will move slowly
N-NE across the western Gulf. Moisture levels begin to increase
and showers and thunderstorms should begin to increase in
coverage especially near the coast. There will be plenty of shear
(SW winds 30-35 knots) over the top of this feature and tropical
development, if any, will be slow to occur. NHC is watching this
area of disturbed weather for tropical development. Whether
development occurs, or not, it looks as the deep plume of moisture
associated with the broad surface low will remain on the east
side of this feature. At this time, the moist axis is aiming for
SC/SE Louisiana and SE TX will likely remain on the west (warmer
and drier) side of this system.

Next Saturday and Sunday, the inverted upper trough will phase a
passing short wave over the mid-Tennessee valley and carve out a
weakness aloft over Texas. The lower heights and slightly deeper
moisture should foster additional showers and thunderstorms
through the weekend. Another short wave moving across the plains
late Monday and Tuesday will re-enforce the lower heights and
keep rain chances in the forecast for the first half of next week.

As for temperatures, kept things on the warm side through Friday
as SE TX will lie on the western side of whatever develops. Clouds
and precip should allow for cooler temperatures near the coast
Fri-Sun. Clouds should keep MinT values above climo through the
period. 43

.MARINE...

Weak high pressure over the western Gulf of Mexico will bring a
light W-SW wind to the coastal waters today and tonight. Winds and
seas will be higher in and near storms this morning and again late
this afternoon. The weak high will remain the dominant feature
through mid week with a light and variable wind. Toward the end of
the week, weak low pressure is expected to develop and move N-NE.
This feature will induce an E-NE wind for Thursday and Friday.
Winds will gradually strengthen especially offshore Fri-Fri Nite
with an increase in seas. The National Hurricane Center is
monitoring the area of disturbed weather in the SW Gulf of Mexico
for possible tropical development. Mariners are urged to stay
prepared and remain alert for changing conditions. Please keep up
with the latest forecast. 43

.TROPICAL...
No significant changes regarding the tropics since the previous
discussion. The National Hurricane Center is still monitoring a
disorganized area of showers and thunderstorms in the Bay of
Campeche. Formation chance in the next 2 days is at 50% and the
formation chance in the next 5 days is medium at 50%. Forecast
tracks, intensity, and specific impacts for Southeast Texas
remain uncertain at this time, but a general northward
progression of this system is expected toward the middle of this
week. In the meantime, be prepared and stay up to date with the
latest forecasts from our office and the National Hurricane
Center. 43

&&

.PRELIMINARY POINT TEMPS/POPS...

College Station (CLL)  76  95  73  96  74 /  10  20  10  10  10
Houston (IAH)          77  95  75  96  75 /  30  30  20  30  10
Galveston (GLS)        81  92  79  89  81 /  20  20  20  20  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...

TX...None.
GM...None.

&&

Special Weather Statement
National Weather Service Houston/Galveston TX
201 PM CDT Mon Jun 14 2021

TXZ226-227-236-237-336-142000-
Inland Brazoria TX-Coastal Matagorda TX-Inland Matagorda TX-
Wharton TX-Fort Bend TX-
201 PM CDT Mon Jun 14 2021

...SPECIAL WEATHER STATEMENT...

At 201 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Wharton to near Boling-Iago to 7 miles
northwest of Sweeny. Movement was southwest at 15 mph.

Winds in excess of 30 mph will be possible with these storms.

Locations impacted include...
Bay City, El Campo, Wharton, Sweeny, Beasley, Kendleton, Wild Peach
Village, Pierce, Markham, Van Vleck, Boling-Iago, Danevang and
Hungerford.

LAT...LON 2919 9641 2898 9630 2882 9589 2909 9562
      2933 9582 2950 9591
TIME...MOT...LOC 1901Z 037DEG 13KT 2935 9601 2920 9592 2912 9577

Special Weather Statement
National Weather Service Houston/Galveston TX
225 PM CDT Mon Jun 14 2021

TXZ210>212-142030-
Waller TX-Colorado TX-Austin TX-
225 PM CDT Mon Jun 14 2021

...SPECIAL WEATHER STATEMENT...

At 225 PM CDT, Doppler radar was tracking a strong thunderstorm 8
miles north of San Felipe, or 10 miles east of Bellville, moving
southwest at 15 mph.

Winds in excess of 30 mph will be possible with this storm.

Locations impacted include...
Sealy, Bellville, San Felipe, Pattison, Monaville and Cat Spring.

LAT...LON 3002 9606 2988 9593 2960 9628 2995 9647
TIME...MOT...LOC 1925Z 058DEG 12KT 2991 9609

Special Weather Statement
National Weather Service Houston/Galveston TX
247 PM CDT Mon Jun 14 2021

TXZ236-336-142045-
Coastal Matagorda TX-Inland Matagorda TX-
247 PM CDT Mon Jun 14 2021

...SPECIAL WEATHER STATEMENT...

At 247 PM CDT, Doppler radar was tracking a strong thunderstorm over
Van Vleck, or over Bay City, moving southwest at 15 mph.

Pea size hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Bay City, South Texas Nuclear Plant, Blessing, Markham, Van Vleck,
Wadsworth and Midfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 2912 9590 2886 9579 2867 9607 2893 9630
TIME...MOT...LOC 1947Z 046DEG 14KT 2901 9592

Special Weather Statement
National Weather Service Houston/Galveston TX
249 PM CDT Mon Jun 14 2021

TXZ195-196-198-142045-
Brazos TX-Grimes TX-Burleson TX-
249 PM CDT Mon Jun 14 2021

...SPECIAL WEATHER STATEMENT...

At 249 PM CDT, Doppler radar was tracking a strong thunderstorm near
Wixon Valley, or 9 miles north of Bryan, moving southwest at 25 mph.

Pea size hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
College Station, Bryan, Snook, Kurten, Wixon Valley, Kyle Field and
Iola.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3073 9662 3073 9660 3071 9660 3070 9656
      3074 9646 3091 9635 3077 9606 3039 9652
      3066 9675
TIME...MOT...LOC 1949Z 048DEG 21KT 3080 9638