Alert archive / Illinois / Tornado Watches in 2017

Tornado Watch 512

November 5, 201730 counties in Illinois; 15 counties in Missouri

The Storm Prediction Center issued this tornado watch at Nov 5, 2017, 12:35 PM CST for 30 counties in Illinois; 15 counties in Missouri. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Nov 5, 2017, 12:35 PM CST (18:35 UTC)
Expired
Nov 5, 2017, 7:00 PM CST
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
60 kt
All 45 counties

Bond County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Fayette County, IL, Jasper County, IL, Jersey County, IL, Lawrence County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Moultrie County, IL, Piatt County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Shelby County, IL, Vermilion 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, Madison County, MO, Osage County, MO, Reynolds 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 Evansville,IN radar (KVWX), 118 km from the middle of the area, began a volume at 18:35 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
50%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
60%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
80%
One or more hailstones of 2 inches or more
50%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Nov 5, 12:54 PM CSTSevere Thunderstorm WarningILXChristian, Macon28 min
Nov 5, 1:44 PM CSTSevere Thunderstorm WarningLSXGreene, Jersey, Macoupin30 min
Nov 5, 1:59 PM CSTSevere Thunderstorm WarningLSXSaint Charles, Saint Louis, City of Saint Louis46 min
Nov 5, 2:17 PM CSTSevere Thunderstorm WarningILXChampaign, Douglas, Edgar, Vermilion43 min
Nov 5, 2:24 PM CSTSevere Thunderstorm WarningLSXFranklin, Jefferson, Saint Louis51 min
Nov 5, 2:27 PM CSTSevere Thunderstorm WarningLSXMadison, Saint Clair48 min
Nov 5, 2:49 PM CSTSevere Thunderstorm WarningILXChristian, Moultrie, Shelby41 min
Nov 5, 2:55 PM CSTSevere Thunderstorm WarningLSXBond, Clinton, Fayette, Madison50 min
Nov 5, 2:57 PM CSTSevere Thunderstorm WarningLSXMonroe, Saint Clair48 min
Nov 5, 3:14 PM CSTSevere Thunderstorm WarningLSXFranklin, Jefferson46 min
Nov 5, 3:35 PM CSTSevere Thunderstorm WarningLSXCrawford, Iron, Washington40 min
Nov 5, 3:37 PM CSTSevere Thunderstorm WarningLSXMonroe41 min
Nov 5, 3:53 PM CSTSevere Thunderstorm WarningLSXJefferson, Saint Francois, Washington21 min
Nov 5, 4:07 PM CSTSevere Thunderstorm WarningLSXMonroe, Randolph, Saint Clair, Washington38 min
Nov 5, 4:12 PM CSTSevere Thunderstorm WarningLSXIron, Madison, Saint Francois, Washington12 min
Nov 5, 4:19 PM CSTSevere Thunderstorm WarningILXClark41 min
Nov 5, 4:42 PM CSTSevere Thunderstorm WarningLSXRandolph22 min
Nov 5, 5:09 PM CSTFlash Flood WarningILXClay, Jasper3 hr
Nov 5, 5:35 PM CSTSevere Thunderstorm WarningLSXMadison, Sainte Genevieve, Saint Francois10 min
Nov 5, 5:36 PM CSTTornado WarningILXCrawford, Lawrence, Richland24 min
Nov 5, 5:57 PM CSTTornado WarningILXCrawford, Lawrence, Richland33 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, 6.6 hours before the alert went out and 153 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, Lincoln, IL at 12:00Z on 2017-11-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1199 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, Lincoln, IL at 12:00Z on 2017-11-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 322 square meters per square second.1939587897117Sfc1 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
1199 J/kg
Mixed-layer CIN
-20 J/kg
Mixed-layer LCL
454 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
322 m²/s²
0-3 km storm-relative helicity
382 m²/s²
Significant tornado parameter
0.0
Supercell composite
9.2

Open this sounding in Storm Lab

The text

As transmitted.

011 
WWUS20 KWNS 051834
SEL2  
SPC WW 051834
ILZ000-MOZ000-060100-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 512
NWS Storm Prediction Center Norman OK
1235 PM CST Sun Nov 5 2017

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Central Illinois
  East-central Missouri

* Effective this Sunday afternoon and evening from 1235 PM until
  700 PM CST.

* Primary threats include...
  A few tornadoes possible
  Widespread large hail likely with isolated very large hail
    events to 2.5 inches in diameter possible
  Scattered damaging wind gusts to 70 mph likely

SUMMARY...Thunderstorms are forming along and ahead of a cold front
sagging through the watch area.  Large hail will be possible in the
strongest cells, along with some risk for a few tornadoes.

The tornado watch area is approximately along and 50 statute miles
north and south of a line from 5 miles north northeast of Terre
Haute IN to 55 miles west northwest of Farmington MO. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU2).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 511...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 2.5 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean
storm motion vector 25035.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Nov 5, 6:04 AM CSTMesoscale DiscussionSPCBond, Champaign, Christian, Clark, Coles, Cumberland and 19 more2 hr
Nov 5, 11:09 AM CSTMesoscale DiscussionSPCBond, Champaign, Christian, Clark, Clay, Clinton and 30 more66 min
Nov 5, 2:51 PM CSTMesoscale DiscussionSPCAlexander, Bond, Christian, Clark, Clay, Clinton and 38 more114 min
Nov 5, 3:50 PM CSTTornado WatchSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more6 hr
Nov 5, 10:48 AM CSTMesoscale DiscussionSPCBartholomew, Brown, Daviess, Dearborn, Decatur, Greene and 8 more57 min
Nov 5, 11:08 AM CSTTornado WatchSPCAdams, Bartholomew, Blackford, Boone, Brown, Carroll and 44 more7 hr
Nov 5, 12:36 PM CSTMesoscale DiscussionSPCBoone, Carroll, Clinton, Grant, Hamilton, Howard and 4 more54 min
Nov 5, 4:58 PM CSTMesoscale DiscussionSPCBartholomew, Brown, Clark, Clay, Crawford, Dearborn and 28 more62 min
Nov 5, 5:31 PM CSTSevere Thunderstorm WatchSPCBartholomew, Brown, Clark, Crawford, Daviess, Dearborn and 20 more6 hr

Nearby

Tornado Watches in Illinois, 2017Tornado Watches in Missouri, 2017Every tornado 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.