Alert archive / Texas / Special Weather Statements in 2021

Special Weather Statement, NWS Houston/Galveston, TX

June 21, 2021Grimes County, Madison County, Texas

NWS Houston/Galveston, TX issued this special weather statement at Jun 21, 2021, 11:58 PM CDT for Grimes County, Madison County, Texas. It was in force for 47 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jun 21, 2021, 11:58 PM CDT (04:58 UTC)
Expired
Jun 22, 2021, 12:45 AM CDT
In force
47 min
Issued by
NWS Houston/Galveston, TX

Counties Grimes County, TX, Madison County, TX

The radar

The Ft Hood radar (KGRK), 131 km from the middle of the area, began a volume at 04:58 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 5.0 hours before the alert went out and 258 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Fort Worth, TX at 00:00Z on 2021-06-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 105 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 00:00Z on 2021-06-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 39 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
105 J/kg
Mixed-layer CIN
-401 J/kg
Mixed-layer LCL
999 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
39 m²/s²
0-3 km storm-relative helicity
159 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Houston/Galveston, TX wrote its last area forecast discussion before this special weather statement went out at Jun 21, 10:11 PM CDT, 1 hour 47 minutes earlier.

Area forecast discussion, Jun 21, 10:11 PM CDT, 1 hour 47 minutes before
Area Forecast Discussion
National Weather Service Houston/Galveston TX
1011 PM CDT Mon Jun 21 2021

.SHORT TERM [Tonight and Tuesday]...
Update sent to raise rain chances along the front as it sags south
then begins to break up as it gets into the Houston area or
perhaps just before. Watching the area around Galveston Bay and
nearshore waters for the potential for rapid strengthening on
storms but not seeing it yet though instability there is high.

Some potential through 4 am for clustering of storms mainly north
and west then shifts down toward the Metro and coastal areas after
4 am.

After the heavy rains in the central/eastern portions of Harris
county (2-5" this afternoon/early evening) these areas don't need
any more rain. The good news is the models have continued to trend
lighter on rain amounts.
45

&&

.AVIATION [00Z TAF Issuance]...
Messy with patchy MVFR ceilings near the coast and across the
north and VFR elsewhere. Watching the storms push down from the
north with the cold front and expect ceilings/visby to lower with
that as storms sag south. Timing this puts it into IAH/HOU around
10-13z. IFR conditions look to develop over the northern sites for
a few hours 9-13z as well and updates for this will be sent
shortly. SCT SHRA/TSRA Tue afternoon and will be carrying VCSH in
most of the TAF sites as confidence on location isn't that high
that it might directly impact sites.
45

&&

.PREV DISCUSSION /Issued 332 PM CDT Mon Jun 21 2021/...

.LONG TERM...[Wednesday through Monday]

By Wednesday morning, a weak upper level ridge will begin to
redevelop over Texas but 500 heights only reach about 591 DM.
Moisture still looks to be trapped beneath the expanding ridge and
feel differential heating will be enough to trigger a few showers
and thunderstorms. The situation looks similar on Thursday with
moisture trapped beneath the ridge and daytime heating will again
foster a chance of showers and thunderstorms. Heat index values
will be on the rise and HI values should range between 100-105
degrees. MaxT values should remain on the warm side with MaxT
values in the lower to middle 90's.

The upper level ridge retreats west on Friday as an inverted upper
trough over the eastern gulf treks west. In addition, a short wave
trough over the northern plains will dig to the SE. Southeast
Texas will lie between the 3 systems but with a decrease in
moisture, not sure that rain chances look all that high on Friday.
Rain chances will increase again on Saturday and Sunday as
additional short wave energy embedded in the jetstream helps carve
out a deeper trough over the central US. 500 heights fall to
around 588 DM and PW values increase to around 2.10 inches. The
combination of lower heights, daytime heating and high moisture
content should set the stage for more showers and thunderstorms
next weekend. SE TX will lie between an upper level ridge over the
NW US and another ridge building over FL. SE TX will lie in the
weakness so diurnally driven showers and thunderstorms will be
possible into early next week. MaxT values will trend slightly
cooler with the lower heights, additional cloud cover and rain
chances. 43

.MARINE...

The pressure gradient will relax tonight as a weak front moves
into SE TX. Will allow the SCA to expire over the Bays and
nearshore waters but will extend the SCA offshore for seas through
00z. A SCEC will be required over the coastal waters through early
Tuesday as seas remain slightly elevated. Wind and seas will be
higher in and near thunderstorms tonight into early Tuesday.  A
light to occasionally moderate onshore flow will persist through
the end of the week with high pressure over the eastern Gulf of
Mexico and lower pressures over the central plains.  43

&&

.PRELIMINARY POINT TEMPS/POPS...

College Station (CLL)  74  88  74  95  77 /  70  30  10  20   0
Houston (IAH)          76  91  76  94  78 /  70  40  20  30  10
Galveston (GLS)        80  90  82  92  84 /  70  50  20  30  10

&&

.HGX WATCHES/WARNINGS/ADVISORIES...

TX...None.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION until 1 AM CDT Tuesday 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.

&&

SHORT TERM...45
LONG TERM...Batiste

In the hours before

Special weather statement, Jun 21, 9:25 PM CDT, 2 hours 33 minutes before
Special Weather Statement
National Weather Service Houston/Galveston TX
925 PM CDT Mon Jun 21 2021

TXZ163-164-220315-
Houston TX-Trinity TX-
925 PM CDT Mon Jun 21 2021

...SPECIAL WEATHER STATEMENT...

At 924 PM CDT, Doppler radar was tracking a strong thunderstorm 8
miles west of Apple Springs, moving southeast at 20 mph.

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

Locations impacted include...
Crockett, Apple Springs, Grapeland, Groveton, Kennard, Latexo,
Pennington and Centralia.

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 3152 9513 3150 9510 3149 9511 3147 9510
      3147 9506 3144 9504 3145 9502 3142 9500
      3141 9498 3141 9497 3138 9495 3134 9496
      3133 9490 3128 9489 3126 9490 3125 9488
      3116 9485 3096 9520 3149 9562 3153 9529
TIME...MOT...LOC 0224Z 333DEG 15KT 3125 9511
Local storm report, Jun 21, 9:50 PM CDT, 2 hours 8 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX
950 PM CDT MON JUN 21 2021

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

0930 PM     FLASH FLOOD      5 NE HOUSTON            29.82N 95.34W
06/21/2021                   HARRIS             TX   BROADCAST MEDIA

            SOCIAL MEDIA REPORT OF A FLOODED CAR AND
            KNEE DEEP WATER NEAR THE INTERSECTION OF
            JENSEN DRIVE AND BENNINGTON STREET.

&&

CB
Special weather statement, Jun 21, 10:23 PM CDT, 1 hour 35 minutes before
Special Weather Statement
National Weather Service Houston/Galveston TX
1023 PM CDT Mon Jun 21 2021

TXZ163-164-177-178-220415-
San Jacinto TX-Walker TX-Houston TX-Trinity TX-
1023 PM CDT Mon Jun 21 2021

...SPECIAL WEATHER STATEMENT...

At 1023 PM CDT, Doppler radar was tracking a strong thunderstorm over
Lovelady, or 14 miles southeast of Austonio, moving south at 15 mph.

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

Locations impacted include...
Trinity, Lovelady, Riverside and Sebastopol.

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 3117 9560 3121 9542 3119 9528 3081 9522
      3081 9561
TIME...MOT...LOC 0323Z 002DEG 10KT 3109 9542
Special weather statement, Jun 21, 11:17 PM CDT, 41 minutes before
Special Weather Statement
National Weather Service Houston/Galveston TX
1117 PM CDT Mon Jun 21 2021

TXZ163-176-177-198-220500-
Madison TX-Walker TX-Grimes TX-Houston TX-
1117 PM CDT Mon Jun 21 2021

...SPECIAL WEATHER STATEMENT...

At 1117 PM CDT, Doppler radar was tracking a strong thunderstorm 10
miles southwest of Austonio, moving south at 20 mph.

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

Locations impacted include...
Madisonville, Austonio and Bedias.

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 3124 9562 3084 9542 3069 9594 3101 9614
      3109 9596 3109 9577 3114 9577 3116 9573
      3121 9575 3123 9573 3124 9573 3126 9568
TIME...MOT...LOC 0417Z 344DEG 17KT 3111 9579
Special weather statement, Jun 21, 11:39 PM CDT, 19 minutes before
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Special weather statement, Jun 21, 11:58 PM CDT, 0 minutes before
Special Weather Statement
National Weather Service Houston/Galveston TX
1158 PM CDT Mon Jun 21 2021

TXZ176-177-198-199-220545-
Madison TX-Walker TX-Grimes TX-Montgomery TX-
1158 PM CDT Mon Jun 21 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN GRIMES...NORTHWESTERN
MONTGOMERY...WESTERN MADISON AND SOUTHWESTERN WALKER COUNTIES UNTIL
1245 AM CDT...

At 1158 PM CDT, Doppler radar was tracking a strong thunderstorm over
Bedias, or 13 miles south of Madisonville, moving south at 20 mph.

Penny size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Madisonville, Bedias, Anderson, Iola, Roans Prairie, Richards, Carlos
and North Zulch.

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 3090 9619 3106 9582 3055 9562 3043 9608
      3085 9617
TIME...MOT...LOC 0458Z 344DEG 16KT 3076 9597

The office that day

Everything else NWS Houston/Galveston, TX issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 21, 7:08 PM CDTFlash Flood WarningHGXHarris3 hr
Jun 21, 7:36 PM CDTAreal Flood AdvisoryHGXHarris, Liberty3 hr
Jun 21, 8:01 PM CDTSpecial Weather StatementHGXHouston, Trinity44 min
Jun 21, 9:25 PM CDTSpecial Weather StatementHGXHouston, Trinity50 min
Jun 21, 10:11 PM CDTSmall Craft AdvisoryHGX3 hr
Jun 21, 10:23 PM CDTSpecial Weather StatementHGXTrinity52 min
Jun 21, 10:25 PM CDTAreal Flood AdvisoryHGXHarris110 min
Jun 21, 11:17 PM CDTSpecial Weather StatementHGXMadison43 min
Jun 21, 11:24 PM CDTSpecial Marine WarningHGX51 min
Jun 21, 11:39 PM CDTSpecial Weather StatementHGXMadison36 min
Jun 22, 12:08 AM CDTSevere Thunderstorm WarningHGXBrazos, Grimes, Madison, Montgomery, Walker52 min
Jun 22, 12:28 AM CDTSpecial Weather StatementHGXBrazoria47 min
Jun 22, 12:56 AM CDTSpecial Weather StatementHGXBrazos, Burleson49 min
Jun 22, 1:14 AM CDTSpecial Weather StatementHGXBrazos, Burleson, Washington91 min
Jun 22, 1:17 AM CDTSpecial Weather StatementHGXBrazoria43 min
Jun 22, 1:28 AM CDTAreal Flood AdvisoryHGXBrazos, Burleson, Grimes2 hr
Jun 22, 1:43 AM CDTSpecial Weather StatementHGXBrazoria47 min
Jun 22, 3:46 AM CDTRip Current StatementHGXBrazoria, Galveston, Matagorda21 hr
Jun 22, 4:28 AM CDTSpecial Weather StatementHGXJackson47 min
Jun 22, 9:24 AM CDTSpecial Marine WarningHGX66 min
Jun 22, 10:55 AM CDTSpecial Marine WarningHGX95 min
Jun 22, 6:08 PM CDTSpecial Weather StatementHGXHarris37 min
Jun 22, 6:57 PM CDTSpecial Weather StatementHGXWharton48 min

Nearby

Special Weather Statements in Texas, 2021Every special weather statement in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.