Alert archive / Missouri / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 97, NWS Kansas City, MO

August 7, 2021Atchison County, Holt County, Missouri

NWS Kansas City, MO issued this severe thunderstorm warning at Aug 7, 2021, 11:16 PM CDT for Atchison County, Holt County, Missouri. It was in force for 44 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 7, 2021, 11:16 PM CDT (04:16 UTC)
Expired
Aug 8, 2021, 12:00 AM CDT
In force
44 min
Issued by
NWS Kansas City, MO
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Atchison County, MO, Holt County, MO

The radar

The Omaha radar (KOAX), 122 km from the middle of the area, began a volume at 04:17 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.

What was reported inside it

TimeReportWhereRemark
Aug 7, 11:16 PM CDTTSTM WND DMG3 Ssw Rockport, MODELAYED REPORT... HIGHWAY SIGN BLOWN OVER AT MM 108 ALONG I-29. TIME ESTIMATED FROM RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 4.3 hours before the alert went out and 122 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, Omaha, NE at 00:00Z on 2021-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2933 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 2021-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 149 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
2933 J/kg
Mixed-layer CIN
-124 J/kg
Mixed-layer LCL
1327 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
149 m²/s²
0-3 km storm-relative helicity
195 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.3

Open this sounding in Storm Lab

The text

As transmitted.

645 
WUUS53 KEAX 080416
SVREAX
MOC005-087-080500-
/O.NEW.KEAX.SV.W.0097.210808T0416Z-210808T0500Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Kansas City/Pleasant Hill MO
1116 PM CDT Sat Aug 7 2021

The National Weather Service in Pleasant Hill has issued a

* Severe Thunderstorm Warning for...
  Atchison County in northwestern Missouri...
  Northwestern Holt County in northwestern Missouri...

* Until midnight CDT.

* At 1115 PM CDT, a severe thunderstorm was located near Peru, or 14
  miles west of Tarkio, moving northeast at 55 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Tarkio, Rock Port, Fairfax, Westboro, Watson, Blanchard, Corning,
  Indian Cave State Park and Phelps City.

This includes Interstate 29 between mile markers 94 and 123.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4058 9520 4048 9520 4048 9518 4024 9518
      4019 9548 4024 9547 4026 9555 4030 9556
      4031 9566 4034 9562 4041 9566 4046 9564
      4046 9568 4048 9570 4055 9566 4056 9568
      4052 9571 4052 9575 4058 9577
TIME...MOT...LOC 0415Z 240DEG 49KT 4041 9566 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Blair
2 follow-up statements
701 
WWUS53 KEAX 080441
SVSEAX

Severe Weather Statement
National Weather Service Kansas City/Pleasant Hill MO
1141 PM CDT Sat Aug 7 2021

MOC005-087-080500-
/O.CON.KEAX.SV.W.0097.000000T0000Z-210808T0500Z/
Atchison MO-Holt MO-
1141 PM CDT Sat Aug 7 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL MIDNIGHT CDT
FOR ATCHISON AND NORTHWESTERN HOLT COUNTIES...

At 1140 PM CDT, a severe thunderstorm was located over Fairfax, or
near Tarkio, moving east at 45 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Tarkio, Fairfax, Westboro, Blanchard and Corning. 

This includes Interstate 29 between mile markers 94 and 101.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4058 9520 4048 9520 4048 9518 4024 9518
      4019 9548 4024 9547 4024 9548 4058 9551
TIME...MOT...LOC 0440Z 257DEG 38KT 4035 9536 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Blair
505 
WWUS53 KEAX 080455
SVSEAX

Severe Weather Statement
National Weather Service Kansas City/Pleasant Hill MO
1155 PM CDT Sat Aug 7 2021

MOC005-087-080504-
/O.EXP.KEAX.SV.W.0097.000000T0000Z-210808T0500Z/
Atchison MO-Holt MO-
1155 PM CDT Sat Aug 7 2021

...THE SEVERE THUNDERSTORM WARNING FOR ATCHISON AND NORTHWESTERN HOLT
COUNTIES WILL EXPIRE AT MIDNIGHT CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with this thunderstorm.

LAT...LON 4058 9520 4048 9520 4048 9518 4024 9518
      4019 9548 4024 9547 4024 9548 4058 9551
TIME...MOT...LOC 0454Z 240DEG 49KT 4043 9517 

$$

Blair

The office that day

Everything else NWS Kansas City, MO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 7, 10:59 PM CDTSpecial Weather StatementEAXAtchison31 min
Aug 7, 11:55 PM CDTSpecial Weather StatementEAXHolt, Nodaway35 min
Aug 8, 2:41 PM CDTHeat AdvisoryEAXAdair, Andrew, Atchison, Bates, Buchanan, Caldwell and 31 more4 days

Nearby

Severe Thunderstorm Warnings in Missouri, 2021Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.