Alert archive / Nebraska / Tornado Watches in 2002

Tornado Watch 156

April 27, 20029 counties in Kansas; 30 counties in Nebraska

The Storm Prediction Center issued this tornado watch at Apr 27, 2002, 12:30 PM CDT for 9 counties in Kansas; 30 counties in Nebraska. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Apr 27, 2002, 12:30 PM CDT (17:30 UTC)
Expired: Apr 27, 2002, 6:00 PM CDT
In force: 6 hr
Issued by: the Storm Prediction Center

All 39 counties

Cloud County, KS, Jewell County, KS, Marshall County, KS, Mitchell County, KS, Nemaha County, KS, Osborne County, KS, Republic County, KS, Smith County, KS, Washington County, KS, Adams County, NE, Buffalo County, NE, Butler County, NE, Cass County, NE, Clay County, NE, Douglas County, NE, Fillmore County, NE, Franklin County, NE, Gage County, NE, Hall County, NE, Hamilton County, NE, Howard County, NE, Jefferson County, NE, Johnson County, NE, Kearney County, NE, Lancaster County, NE, Merrick County, NE, Nuckolls County, NE, Otoe County, NE, Pawnee County, NE, Polk County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Sherman County, NE, Thayer County, NE, Washington County, NE, Webster County, NE, York County, NE

The radar

The Grand Island radar (KUEX), 51 km from the middle of the area, began a volume at 17:20 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.

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Apr 27, 3:10 PM CDT	Tornado Warning	OAX	Lancaster, Saline, Seward	35 min

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 5.5 hours before the alert went out and 156 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: 471 m above ground
0-6 km bulk shear: 58 kt
0-1 km storm-relative helicity: 164 m²/s²
0-3 km storm-relative helicity: 277 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.

000
WWUS20 KWNS 271721
SEL6  
SPC WW 271714
KSZ000-NEZ000-272300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 156
STORM PREDICTION CENTER NORMAN OK
1214 PM CDT SAT APR 27 2002

THE STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

   NORTHERN KANSAS                             
   SOUTHEASTERN NEBRASKA                           

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 1230 PM UNTIL
600 PM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 70 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 40 MILES SOUTH SOUTHWEST OF KEARNEY NEBRASKA
TO 45 MILES SOUTH OF OMAHA NEBRASKA.

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.

DISCUSSION...THUNDERSTORMS ARE BEGINNING TO DEVELOP JUST AHEAD OF
AN UPPER LEVEL TROUGH AND THE STORMS SHOULD STRENGTHEN THROUGH THE
AFTERNOON AS THE AIR MASS DESTABLIZES. THE GREATEST THREAT WILL BE
LARGE HAIL...ESPECIALLY NORTH OF THE WARM FRONT...BUT THE STRONG
LOW LEVEL SHEAR/ENVIRONMENTAL WINDS SUGGESTS A TORNADO THREAT WITH
STORMS LOCATED CLOSE TO THE WARM FRONT. 

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. 
MEAN STORM MOTION VECTOR 25035.

...IMY

411,0991 413,0955 393,0955 391,0991

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 27, 3:00 PM CDT	Tornado Watch	SPC	Anderson, Atchison, Coffey, Douglas, Franklin, Greenwood and 13 more	5 hr
Apr 27, 3:30 PM CDT	Tornado Watch	SPC	Brown, Doniphan	5 hr

Nearby

Tornado Watches in Nebraska, 2002 Tornado Watches in Kansas, 2002 Every tornado watch in 2002

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.