Alert archive / Illinois / Tornado Watches in 2014

Tornado Watch 13

February 20, 201418 counties in Illinois; 15 counties in Indiana

The Storm Prediction Center issued this tornado watch at Feb 20, 2014, 4:45 PM CST for 18 counties in Illinois; 15 counties in Indiana. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Feb 20, 2014, 4:45 PM CST (22:45 UTC)
Expired
Feb 20, 2014, 7:57 PM CST
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 33 counties

Champaign County, IL, Clark County, IL, Clay 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, Lawrence County, IL, Marion County, IL, Moultrie County, IL, Piatt County, IL, Richland County, IL, Shelby County, IL, Vermilion County, IL, Clay County, IN, Daviess County, IN, Fountain County, IN, Greene County, IN, Knox County, IN, Martin County, IN, Montgomery County, IN, Owen County, IN, Parke County, IN, Putnam County, IN, Sullivan County, IN, Tippecanoe County, IN, Vermillion County, IN, Vigo County, IN, Warren County, IN

The radar

The Lincoln radar (KILX), 120 km from the middle of the area, began a volume at 22:45 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
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
10%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Feb 20, 4:47 PM CSTTornado WarningILXEffingham, Moultrie, Shelby28 min
Feb 20, 5:06 PM CSTSevere Thunderstorm WarningILXClark, Coles, Crawford, Cumberland, Douglas, Edgar and 3 more54 min
Feb 20, 5:09 PM CSTSevere Thunderstorm WarningLSXClinton, Fayette, Marion, Washington51 min
Feb 20, 5:12 PM CSTTornado WarningILXColes, Douglas, Edgar33 min
Feb 20, 5:14 PM CSTTornado WarningILXClark, Coles, Cumberland, Edgar31 min
Feb 20, 5:42 PM CSTFlash Flood WarningILXDeWitt, Macon, Moultrie, Piatt, Shelby6 hr
Feb 20, 5:45 PM CSTTornado WarningILXEdgar, Vermilion30 min
Feb 20, 5:46 PM CSTSevere Thunderstorm WarningINDFountain, Montgomery, Parke, Putnam, Vermillion, Vigo44 min
Feb 20, 5:48 PM CSTFlash Flood WarningILXChampaign, Clark, Clay, Coles, Crawford, Cumberland and 7 more6 hr
Feb 20, 6:01 PM CSTSevere Thunderstorm WarningILXClark, Edgar14 min
Feb 20, 6:08 PM CSTSevere Thunderstorm WarningINDClay, Owen, Parke, Putnam, Vigo52 min
Feb 20, 6:16 PM CSTTornado WarningINDDaviess, Knox44 min
Feb 20, 6:25 PM CSTSevere Thunderstorm WarningINDBoone, Clinton, Fountain, Hendricks, Montgomery, Parke and 2 more50 min
Feb 20, 6:31 PM CSTTornado WarningINDParke29 min
Feb 20, 6:50 PM CSTTornado WarningINDDaviess, Knox40 min
Feb 20, 7:10 PM CSTTornado WarningINDDaviess, Greene, Martin35 min
Feb 20, 7:30 PM CSTSevere Thunderstorm WarningINDBrown, Greene, Jackson, Lawrence, Monroe, Morgan and 1 more45 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, 10.8 hours before the alert went out and 82 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 2014-02-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Lincoln, IL at 12:00Z on 2014-02-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 582 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
507 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
582 m²/s²
0-3 km storm-relative helicity
576 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

521 
WWUS20 KWNS 202246
SEL3  
SPC WW 202246
ILZ000-INZ000-210300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 13
NWS STORM PREDICTION CENTER NORMAN OK
445 PM CST THU FEB 20 2014

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  CENTRAL AND EASTERN ILLINOIS
  WESTERN INDIANA

* EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 445 PM UNTIL
  900 PM CST.

* PRIMARY THREATS INCLUDE...
  SEVERAL TORNADOES POSSIBLE
  SEVERAL DAMAGING WIND GUSTS TO 70 MPH POSSIBLE

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE
MILES EAST AND WEST OF A LINE FROM 15 MILES NORTH NORTHWEST OF
DANVILLE ILLINOIS TO 25 MILES SOUTHEAST OF MOUNT VERNON ILLINOIS.
 FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU3).

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...THIS TORNADO WATCH REPLACES SEVERE
THUNDERSTORM WATCH NUMBER 12. WATCH NUMBER 12 WILL NOT BE IN
EFFECT AFTER 445 PM CST. CONTINUE...WW 9...WW 10...WW 11...

DISCUSSION...SFC PRESSURE FALLS AND 60 KT SSWLY NEAR-SFC FLOW
SUGGEST THAT APPRECIABLE LOW-LVL AIR MASS RECOVERY WILL CONTINUE
OVER THE NEXT FEW HOURS AHEAD OF EXISTING BROKEN LINE OF SUPERCELLS
IN CNTRL IL. CONTINUED DEEPENING OF ASSOCIATED SFC LOW NOW NEAR
DVN...COUPLED WITH CONTINUED ENE MOTION OF STRONG MID-LVL SHORTWAVE
IMPULSE...AND 700 MB SWLY WIND SPEEDS INCREASING TO AOA 70 KTS
TOGETHER SUGGEST POTENTIAL FOR A COUPLE TORNADOES...IN ADDITION TO
DMGG WIND.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450.
MEAN STORM MOTION VECTOR 24055.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 20, 11:34 AM CSTMesoscale DiscussionSPCBrown, Calhoun, Cass, Greene, Jersey, Macoupin and 3 more116 min
Feb 20, 1:36 PM CSTSevere Thunderstorm WatchSPCAdams, Bond, Brown, Calhoun, Christian, Clinton and 15 more4 hr
Feb 20, 1:45 PM CSTMesoscale DiscussionSPCAlexander, Gallatin, Hardin, Johnson, Massac, Pope and 5 more2 hr
Feb 20, 2:23 PM CSTTornado WatchSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more7 hr
Feb 20, 3:23 PM CSTMesoscale DiscussionSPCBond, Calhoun, Christian, Clark, Clay, Clinton and 25 more97 min
Feb 20, 3:50 PM CSTSevere Thunderstorm WatchSPCClark, Clay, Coles, Crawford, Cumberland, DeWitt and 11 more56 min
Feb 20, 5:29 PM CSTMesoscale DiscussionSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 14 more46 min
Feb 20, 5:45 PM CSTTornado WatchSPCBartholomew, Boone, Brown, Carroll, Clark, Clinton and 36 more5 hr

Nearby

Tornado Watches in Illinois, 2014Tornado Watches in Indiana, 2014Every tornado watch in 2014

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.