Alert archive / Missouri / Tornado Watches in 2019

Tornado Watch 207

May 21, 201922 counties in Illinois; 38 counties in Missouri

The Storm Prediction Center issued this tornado watch at May 21, 2019, 3:10 PM CDT for 22 counties in Illinois; 38 counties in Missouri. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued: May 21, 2019, 3:10 PM CDT (20:10 UTC)
Expired: May 21, 2019, 11:00 PM CDT
In force: 8 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 65 kt

All 60 counties

Alexander County, IL, Bond County, IL, Calhoun County, IL, Clinton County, IL, Fayette County, IL, Franklin County, IL, Greene County, IL, Jackson County, IL, Jefferson County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Perry County, IL, Pike County, IL, Randolph County, IL, Saint Clair County, IL, Union County, IL, Washington County, IL, Williamson County, IL, Audrain County, MO, Bollinger County, MO, Boone County, MO, Butler County, MO, Callaway County, MO, Cape Girardeau County, MO, Carter County, MO, City of Saint Louis, MO, Cole County, MO, Cooper County, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Howard County, MO, Iron County, MO, Jefferson County, MO, Lincoln County, MO, Madison County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, New Madrid County, MO, Osage County, MO, Perry County, MO, Pike County, MO, Ralls County, MO, Randolph County, MO, Reynolds County, MO, Ripley County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Scott County, MO, Stoddard County, MO, Warren County, MO, Washington County, MO, Wayne County, MO

The radar

The St Louis radar (KLSX), 41 km from the middle of the area, began a volume at 20:11 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes: 60%
One or more EF2 to EF5 tornadoes: 20%
Ten or more severe wind reports: 80%
One or more gusts of 65 knots or more: 40%
Ten or more severe hail reports: 40%
One or more hailstones of 2 inches or more: 10%
Six or more combined severe hail and wind reports: 95%

Warnings issued inside it

45 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
May 21, 3:59 PM CDT	Severe Thunderstorm Warning	LSX	Boone, Callaway, Cole, Osage	46 min
May 21, 4:40 PM CDT	Severe Thunderstorm Warning	LSX	Audrain, Boone, Callaway, Gasconade, Montgomery, Osage	50 min
May 21, 4:42 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Franklin, Gasconade	63 min
May 21, 4:48 PM CDT	Tornado Warning	LSX	Callaway, Gasconade, Montgomery, Osage	27 min
May 21, 5:06 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Iron, Reynolds, Washington	54 min
May 21, 5:12 PM CDT	Tornado Warning Tornado observed	LSX	Audrain, Callaway, Lincoln, Montgomery, Pike, Warren	48 min
May 21, 5:21 PM CDT	Severe Thunderstorm Warning	PAH	Carter, Ripley	54 min
May 21, 5:22 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Franklin, Gasconade, Saint Charles, Warren, Washington	38 min
May 21, 5:34 PM CDT	Severe Thunderstorm Warning	LSX	Iron, Washington	26 min
May 21, 5:40 PM CDT	Tornado Warning	LSX	Franklin, Saint Charles, Saint Louis, Warren	50 min
May 21, 5:57 PM CDT	Severe Thunderstorm Warning	LSX	Lincoln, Saint Charles, Warren	33 min
May 21, 5:59 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Franklin, Iron, Jefferson, Madison, Reynolds and 3 more	76 min
May 21, 6:19 PM CDT	Tornado Warning Tornado observed	LSX	Calhoun	41 min
May 21, 6:32 PM CDT	Severe Thunderstorm Warning	LSX	Madison, Monroe, Randolph, Saint Clair	88 min
May 21, 6:36 PM CDT	Severe Thunderstorm Warning	PAH	Ripley	39 min
May 21, 6:48 PM CDT	Tornado Warning	LSX	Monroe, Saint Clair	42 min
May 21, 6:55 PM CDT	Tornado Warning	LSX	Jersey, Macoupin, Madison	50 min
May 21, 7:04 PM CDT	Severe Thunderstorm Warning	PAH	Butler, Wayne	26 min
May 21, 7:08 PM CDT	Tornado Warning	LSX	Madison, Saint Clair	37 min
May 21, 7:36 PM CDT	Severe Thunderstorm Warning	LSX	Bond, Clinton, Macoupin, Madison, Montgomery	39 min
May 21, 7:46 PM CDT	Tornado Warning	LSX	Bond, Madison	29 min
May 21, 7:53 PM CDT	Severe Thunderstorm Warning	PAH	Bollinger	37 min
May 21, 7:56 PM CDT	Severe Thunderstorm Warning	LSX	Bond, Clinton, Marion, Saint Clair, Washington	53 min
May 21, 8:06 PM CDT	Tornado Warning	PAH	Bollinger, Cape Girardeau	24 min
May 21, 8:08 PM CDT	Severe Thunderstorm Warning	LSX	Bond, Clinton, Fayette, Montgomery	52 min
May 21, 8:25 PM CDT	Severe Thunderstorm Warning	PAH	Cape Girardeau, Perry	35 min
May 21, 8:27 PM CDT	Tornado Warning	LSX	Bond, Clinton, Fayette, Marion	21 min
May 21, 8:31 PM CDT	Severe Thunderstorm Warning	PAH	Bollinger, Cape Girardeau	29 min
May 21, 8:40 PM CDT	Severe Thunderstorm Warning	PAH	Jackson	35 min
May 21, 8:44 PM CDT	Tornado Warning	PAH	Cape Girardeau, Perry	31 min
May 21, 8:45 PM CDT	Severe Thunderstorm Warning	LSX	Clinton, Fayette, Marion, Montgomery	45 min
May 21, 8:49 PM CDT	Tornado Warning	PAH	Jackson	26 min
May 21, 9:05 PM CDT	Severe Thunderstorm Warning	PAH	Perry	40 min
May 21, 9:06 PM CDT	Flash Flood Warning	PAH	Carter, Ripley	3 hr
May 21, 9:08 PM CDT	Tornado Warning	PAH	Perry	37 min
May 21, 9:13 PM CDT	Severe Thunderstorm Warning	PAH	Jackson	32 min
May 21, 9:15 PM CDT	Severe Thunderstorm Warning	PAH	Alexander	30 min
May 21, 9:36 PM CDT	Tornado Warning	PAH	Franklin, Jackson, Perry	24 min
May 21, 9:36 PM CDT	Tornado Warning	PAH	Alexander, Jackson, Union, Williamson	39 min
May 21, 9:40 PM CDT	Severe Thunderstorm Warning	PAH	Jefferson	35 min
May 21, 9:46 PM CDT	Tornado Warning	PAH	Jefferson	29 min
May 21, 10:00 PM CDT	Tornado Warning	PAH	Franklin, Jefferson	30 min
May 21, 10:05 PM CDT	Severe Thunderstorm Warning	PAH	Alexander, Union	25 min
May 21, 10:20 PM CDT	Severe Thunderstorm Warning	PAH	Franklin, Williamson	40 min
May 21, 10:33 PM CDT	Severe Thunderstorm Warning	PAH	Johnson, Union, Williamson	42 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 8.2 hours before the alert went out and 263 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1157 m above ground
0-6 km bulk shear: 76 kt
0-1 km storm-relative helicity: 331 m²/s²
0-3 km storm-relative helicity: 917 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 21, 12:55 AM CDT	Mesoscale Discussion	SPC	Alexander, Jackson, Monroe, Randolph, Saint Clair, Union	95 min
May 21, 5:43 PM CDT	Mesoscale Discussion	SPC	Alexander, Bond, Calhoun, Clinton, Greene, Jackson and 12 more	62 min
May 20, 8:20 PM CDT	Severe Thunderstorm Watch	SPC	Benton, Camden, Dent, Hickory, Howell, Laclede and 10 more	8 hr
May 20, 10:30 PM CDT	Mesoscale Discussion	SPC	Barry, Christian, Dade, Dallas, Douglas, Greene and 11 more	60 min
May 20, 11:06 PM CDT	Mesoscale Discussion	SPC	McDonald	24 min
May 21, 12:18 AM CDT	Tornado Watch	SPC	Barry, Christian, Douglas, Howell, McDonald, Ozark and 4 more	5 hr
May 21, 9:57 AM CDT	Mesoscale Discussion	SPC	Camden, Christian, Dallas, Douglas, Greene, Hickory and 10 more	93 min
May 21, 11:32 AM CDT	Tornado Watch	SPC	Barry, Camden, Christian, Dallas, Dent, Douglas and 16 more	7 hr
May 21, 1:51 PM CDT	Mesoscale Discussion	SPC	Camden, Dent, Douglas, Laclede, Maries, Ozark and 6 more	84 min
May 21, 4:43 PM CDT	Mesoscale Discussion	SPC	Dunklin, Pemiscot	62 min
May 21, 6:12 PM CDT	Mesoscale Discussion	SPC	Saint Charles, Saint Louis, City of Saint Louis	33 min
May 21, 6:53 PM CDT	Severe Thunderstorm Watch	SPC	Atchison, Holt	3 hr

Nearby

Tornado Watches in Missouri, 2019 Tornado Watches in Illinois, 2019 Every tornado watch in 2019

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.