Alert archive / Texas / Special Weather Statements in 2020

Special Weather Statement, NWS Austin/San Antonio, TX

March 21, 2020Karnes County, Texas

NWS Austin/San Antonio, TX issued this special weather statement at Mar 21, 2020, 9:57 AM CDT for Karnes County, Texas. It was in force for 63 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: Mar 21, 2020, 9:57 AM CDT (14:57 UTC)
Expired: Mar 21, 2020, 11:00 AM CDT
In force: 63 min
Issued by: NWS Austin/San Antonio, TX

County Karnes County, TX

The radar

The Austin/San Antonio radar (KEWX), 97 km from the middle of the area, began a volume at 14:56 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

Corpus Christi, TX (KCRP), launched 12:00Z, 3.0 hours before the alert went out and 147 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 465 m above ground
0-6 km bulk shear: 49 kt
0-1 km storm-relative helicity: 344 m²/s²
0-3 km storm-relative helicity: 425 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.9

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 Austin/San Antonio, TX wrote its last area forecast discussion before this special weather statement went out at Mar 21, 6:49 AM CDT, 3 hours 8 minutes earlier.

Area forecast discussion, Mar 21, 6:49 AM CDT, 3 hours 8 minutes before

Area Forecast Discussion
National Weather Service Austin/San Antonio TX
649 AM CDT Sat Mar 21 2020

.UPDATE...
Please see the 12Z aviation forecast discussion below.

&&

.AVIATION...
Light shower activity continues to slowly develop early this
morning. Coverage is still fairly low along the I-35 corridor and we
will only mention VCSH through this morning. Shower activity will
increase during the afternoon hours and we will continue to mention
prevailing SHRA along with IFR cigs. We did opt to add a TEMPO group
for TSRA between 20-01Z based on recent HREF data. Cigs remain IFR
through the late evening and early morning hours on Sunday as -DZ and
BR develop. For DRT, shower activity will be quicker to develop as
cigs drop into IFR by late morning. We did not mention TSRA at DRT as
it appears the better chance for storms will remain east of the
terminal. Showers should end by early evening, but with developing
-DZ and BR, cigs will remain IFR.

&&

.PREV DISCUSSION... /ISSUED 408 AM CDT Sat Mar 21 2020/

SHORT TERM (Today through Sunday)...
Light showers are noted from the Rio Grande plains eastward into the
coastal plains and Highway 77 corridor early this morning. We will
see a steady increase in shower activity from the southwest to the
northeast today as isentropic ascent increases. With above normal
moisture in place (precipitable water values 1-1.5"), beneficial
rains are in store today. Rainfall amounts will be highest along and
east of I-35, with some localized amounts near 2" possible in the
coastal plains. We do not expect any significant flooding concerns,
other than perhaps a low potential for some minor flooding of low-
lying and normally flood prone areas. Given the ongoing drought
across the region, any rainfall will be beneficial to the region.
With the rain, cool north winds and cloud cover, highs today will
remain below normal, with 50s in store for most areas.

Rain chances begin to decrease late tonight into early Sunday
morning and will be confined to areas mainly along and east of
Highway 281. With wet ground across the region, we do expect fog
development tonight into Sunday morning. We can't rule out a stray
shower or two on Sunday, and will only mention a 20% chance for
areas generally east of the I-35/I-37 corridors. Southerly winds
return on Sunday and this will result in highs quickly warming into
the upper 60s to upper 70s.

LONG TERM (Sunday Night through Friday)...
With ridging building in, the long term forecast becomes warm and
dry with little to no rain chances through the week. Temperatures
increase daily into the late week with highs in the 90s by Wednesday
and Thursday. Another approaching shortwave dips into the Plains
next Friday bringing a cold front that should lead us into a cooler
weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry              54  53  75  64  80 / 100  90  20  10  -
Austin Bergstrom Intl Airport  56  53  76  63  81 / 100  90  20  10  10
New Braunfels Muni Airport     54  53  76  63  81 /  90  90  20  -   -
Burnet Muni Airport            52  50  73  60  78 /  90  80  10  -   -
Del Rio Intl Airport           57  54  77  59  84 /  50  10   0   0  -
Georgetown Muni Airport        54  52  74  62  79 /  90  90  20  10  -
Hondo Muni Airport             56  52  76  61  84 /  90  70  10   0  -
San Marcos Muni Airport        54  53  76  63  81 / 100  90  20  10  -
La Grange - Fayette Regional   60  58  79  66  82 / 100 100  20  10  10
San Antonio Intl Airport       54  53  75  64  81 /  90  80  10  -   -
Stinson Muni Airport           55  53  77  64  83 /  90  80  10  -   -

&&

.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&

Short-Term/Aviation...Platt
Long-Term...YB

Hazardous weather outlook, Mar 21, 4:43 AM CDT, 5 hours 14 minutes before

Hazardous Weather Outlook
National Weather Service Austin/San Antonio TX
443 AM CDT Sat Mar 21 2020

TXZ171>173-183>194-202>209-217>225-228-220945-
Llano-Burnet-Williamson-Val Verde-Edwards-Real-Kerr-Bandera-
Gillespie-Kendall-Blanco-Hays-Travis-Bastrop-Lee-Kinney-Uvalde-
Medina-Bexar-Comal-Guadalupe-Caldwell-Fayette-Maverick-Zavala-
Frio-Atascosa-Wilson-Karnes-Gonzales-De Witt-Lavaca-Dimmit-
443 AM CDT Sat Mar 21 2020

This Hazardous Weather Outlook is for South-Central Texas..

.DAY ONE...Today And Tonight.

Rainfall chances will increase across south central Texas today.
Rainfall amounts will be highest generally along and east of the
I-35 corridor. Some minor flooding is possible in low-lying and
normally flood prone areas.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.

In the hours before

Special weather statement, Mar 21, 9:17 AM CDT, 40 minutes before

Special Weather Statement
National Weather Service Austin/San Antonio TX
917 AM CDT Sat Mar 21 2020

TXZ220-222-211500-
Karnes TX-Atascosa TX-
917 AM CDT Sat Mar 21 2020

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN KARNES AND
SOUTHEASTERN ATASCOSA COUNTIES UNTIL 1000 AM CDT...

At 916 AM CDT, Doppler radar was tracking a strong thunderstorm over
Whitsett, or 7 miles north of Choke Canyon, moving northeast at 20
mph.

Half inch hail will be possible with this storm.

Locations impacted include...
Karnes City, Campbellton, Coy City, Peggy, Deweesville, McCoy and
Fashing.

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 2864 9834 2864 9842 2896 9840 2895 9825
      2888 9819 2894 9812 2892 9788 2872 9803
      2879 9810 2861 9833
TIME...MOT...LOC 1416Z 204DEG 19KT 2861 9830

KCW

Special weather statement, Mar 21, 9:57 AM CDT, 0 minutes before

Special Weather Statement
National Weather Service Austin/San Antonio TX
957 AM CDT Sat Mar 21 2020

TXZ220>222-211600-
Karnes TX-Atascosa TX-Wilson TX-
957 AM CDT Sat Mar 21 2020

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN KARNES...
SOUTHEASTERN ATASCOSA AND SOUTHWESTERN WILSON COUNTIES UNTIL 1100 AM
CDT...

At 957 AM CDT, Doppler radar was tracking a strong thunderstorm 7
miles northeast of Campbellton, moving northeast at 20 mph.

Half inch hail will be possible with this storm.

Locations impacted include...
Poth, Campbellton, Falls City, Cestohowa, Hobson, Coy City, Peggy,
Paweleville, Deweesville, Fashing and Pana Maria.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Occasional 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 2872 9835 2913 9823 2905 9784 2872 9803
      2879 9810 2872 9819
TIME...MOT...LOC 1457Z 204DEG 19KT 2881 9820

KCW

The office that day

Everything else NWS Austin/San Antonio, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 21, 9:17 AM CDT	Special Weather Statement	EWX	Karnes	43 min
Mar 21, 10:08 AM CDT	Severe Thunderstorm Warning	EWX	Atascosa, Karnes, Wilson	37 min
Mar 21, 10:53 AM CDT	Special Weather Statement	EWX	Wilson	37 min
Mar 21, 12:53 PM CDT	Areal Flood Advisory	EWX	DeWitt, Karnes	112 min
Mar 21, 1:27 PM CDT	Severe Thunderstorm Warning	EWX	DeWitt, Lavaca	14 min
Mar 21, 2:00 PM CDT	Severe Thunderstorm Warning	EWX	Lavaca	21 min
Mar 21, 2:25 PM CDT	Areal Flood Advisory	EWX	DeWitt, Karnes	4 hr
Mar 21, 2:30 PM CDT	Special Weather Statement	EWX	Kerr	30 min
Mar 21, 3:19 PM CDT	Areal Flood Advisory	EWX	Lavaca	3 hr
Mar 21, 3:29 PM CDT	Special Weather Statement	EWX	Gillespie	31 min
Mar 21, 4:03 PM CDT	Special Weather Statement	EWX	Gillespie	27 min

Nearby

Special Weather Statements in Texas, 2020 Every special weather statement in 2020

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.