Alert archive / Missouri / Severe Thunderstorm Watches in 2017
Severe Thunderstorm Watch 245
The Storm Prediction Center issued this severe thunderstorm watch at May 19, 2017, 4:16 AM CDT for 14 counties in Illinois; 15 counties in Missouri. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- May 19, 2017, 4:16 AM CDT (09:16 UTC)
- Expired
- May 19, 2017, 7:32 AM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 29 counties
Bond County, IL, Calhoun County, IL, Clinton County, IL, Fayette County, IL, Greene County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Randolph County, IL, Saint Clair County, IL, Washington County, IL, City of Saint Louis, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Iron County, MO, Jefferson County, MO, Lincoln County, MO, Madison County, MO, Montgomery County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Warren County, MO, Washington County, MO
The radar
The St Louis radar (KLSX), 20 km from the middle of the area, began a volume at 09:18 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
- 10%
- One or more EF2 to EF5 tornadoes
- 2%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
5 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 19, 4:20 AM CDT | Tornado Warning | LSX | Callaway, Montgomery, Warren | 25 min |
| May 19, 4:37 AM CDT | Severe Thunderstorm Warning | LSX | Calhoun | 53 min |
| May 19, 4:39 AM CDT | Severe Thunderstorm Warning | LSX | Calhoun, Monroe | 66 min |
| May 19, 5:13 AM CDT | Severe Thunderstorm Warning | LSX | Clinton, Jersey, Madison, Saint Clair | 62 min |
| May 19, 5:36 AM CDT | Severe Thunderstorm Warning | LSX | Bond, Fayette, Greene, Macoupin, Montgomery | 69 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 00:00Z, 9.3 hours before the alert went out and 230 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.
- Mixed-layer CAPE
- 631 J/kg
- Mixed-layer CIN
- -32 J/kg
- Mixed-layer LCL
- 2069 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 17 m²/s²
- 0-3 km storm-relative helicity
- 30 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.7
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 19, 4:07 AM CDT | Mesoscale Discussion | SPC | Bond, Calhoun, Clinton, Fayette, Greene, Jersey and 8 more | 113 min |
| May 19, 6:30 AM CDT | Mesoscale Discussion | SPC | Bond, Clay, Clinton, Crawford, Cumberland, Effingham and 9 more | 90 min |
| May 19, 3:06 PM CDT | Tornado Watch | SPC | Calhoun | 7 hr |
| May 19, 6:04 PM CDT | Mesoscale Discussion | SPC | Calhoun | 86 min |
| May 18, 7:06 PM CDT | Mesoscale Discussion | SPC | Buchanan, Caldwell, Cass, Clay, Clinton, Jackson and 4 more | 84 min |
| May 18, 9:41 PM CDT | Mesoscale Discussion | SPC | Barry, Barton, Bates, Benton, Cass, Cedar and 18 more | 94 min |
| May 18, 9:41 PM CDT | Severe Thunderstorm Watch | SPC | Andrew, Bates, Buchanan, Caldwell, Cass, Clay and 9 more | 4 hr |
| May 18, 10:58 PM CDT | Tornado Watch | SPC | Barry, Christian, Douglas, Greene, Howell, Lawrence and 10 more | 6 hr |
| May 18, 11:48 PM CDT | Mesoscale Discussion | SPC | Barry, Christian, McDonald, Newton, Stone, Taney | 57 min |
| May 19, 2:13 PM CDT | Mesoscale Discussion | SPC | Barry, Christian, Dade, Douglas, Greene, Howell and 9 more | 92 min |
| May 19, 5:03 PM CDT | Mesoscale Discussion | SPC | Butler, Dunklin, Mississippi, New Madrid, Pemiscot, Stoddard | 117 min |
Nearby
Severe Thunderstorm Watches in Missouri, 2017Severe Thunderstorm Watches in Illinois, 2017Every severe thunderstorm watch in 2017
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.