Alert archive / Nebraska / Tornado Watches in 2007

Tornado Watch 162

April 22, 200716 counties in Kansas; 42 counties in Nebraska

The Storm Prediction Center issued this tornado watch at Apr 22, 2007, 11:30 AM CDT for 16 counties in Kansas; 42 counties in Nebraska. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 22, 2007, 11:30 AM CDT (16:30 UTC)
Expired
Apr 22, 2007, 5:03 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 58 counties

Atchison County, KS, Brown County, KS, Clay County, KS, Cloud County, KS, Doniphan County, KS, Geary County, KS, Jackson County, KS, Jefferson County, KS, Marshall County, KS, Nemaha County, KS, Pottawatomie County, KS, Republic County, KS, Riley County, KS, Shawnee County, KS, Wabaunsee County, KS, Washington County, KS, Adams County, NE, Antelope County, NE, Boone County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Cedar County, NE, Clay County, NE, Colfax County, NE, Cuming County, NE, Dodge County, NE, Douglas County, NE, Fillmore County, NE, Gage County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Howard County, NE, Jefferson County, NE, Johnson County, NE, Knox County, NE, Lancaster County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Nemaha County, NE, Nuckolls County, NE, Otoe County, NE, Pawnee County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Thayer County, NE, Washington County, NE, Wayne County, NE, York County, NE

The radar

The Grand Island radar (KUEX), 94 km from the middle of the area, began a volume at 16:31 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
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 22, 2:43 PM CDTTornado WarningOAXPierce32 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

Omaha, NE (KOAX), launched 12:00Z, 4.5 hours before the alert went out and 113 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, Omaha, NE at 12:00Z on 2007-04-22Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 12:00Z on 2007-04-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -53 square meters per square second.19395878Sfc1 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
1189 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
-53 m²/s²
0-3 km storm-relative helicity
-25 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 221636
SEL2  
SPC WW 221636
KSZ000-MOZ000-NEZ000-230000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 162
NWS STORM PREDICTION CENTER NORMAN OK
1140 AM CDT SUN APR 22 2007

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

       NORTHEAST KANSAS
       EXTREME NORTHWEST MISSOURI
       SOUTHEAST NEBRASKA

EFFECTIVE THIS SUNDAY MORNING AND EVENING FROM 1140 AM UNTIL 700
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 APPROXIMATELY ALONG AND 75 STATUTE
MILES EAST AND WEST OF A LINE FROM 35 MILES NORTHWEST OF COLUMBUS
NEBRASKA TO 25 MILES EAST OF MANHATTAN KANSAS.  FOR A COMPLETE
DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE
(WOUS64 KWNS WOU2).

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...ENVIRONMENT EXPECTED TO BECOME INCREASINGLY SUPPORTIVE
OF RELATIVELY LOW-TOPPED ROTATING STORMS ACROSS FROM SOUTHEAST
NEB/NORTHEAST KS EAST TO EXTREME NORTHWEST MO THROUGH THE AFTERNOON
AS DEEP-LAYER CYCLONE TRANSITIONS ENEWD ACROSS THE REGION. POCKETS
OF STRONGER SURFACE HEATING WITHIN SYSTEM DRY SLOT WILL CONTRIBUTE
TO CONTINUED DESTABILIZATION AND INCREASING STORM COVERAGE AND
INTENSITY. IN ADDITION TO COOLING ALOFT AND ADEQUATE DEEP-LAYER
SHEAR FOR HAIL STORMS...ENHANCED LOW LEVEL SHEAR NEAR THE LOW...AND
UPDRAFT STRETCHING IN AREAS WITH GREATER LOW-LEVEL CAPE SHOULD LEAD
TO A GREATER CHANCE FOR SOME TORNADIC CELLS.

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
400. MEAN STORM MOTION VECTOR 20035.


...CARBIN/CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 21, 10:45 PM CDTMesoscale DiscussionSPCBarber, Comanche60 min
Apr 22, 10:57 AM CDTMesoscale DiscussionSPCAtchison, Brown, Clay, Cloud, Dickinson, Doniphan and 20 more93 min
Apr 22, 3:07 PM CDTMesoscale DiscussionSPCAllen, Anderson, Bourbon, Cherokee, Coffey, Crawford and 13 more113 min
Apr 21, 10:34 PM CDTSevere Thunderstorm WatchSPCAntelope, Blaine, Boyd, Brown, Cherry, Garfield and 8 more3 hr
Apr 22, 1:25 PM CDTMesoscale DiscussionSPCBurt, Washington95 min
Apr 22, 1:56 PM CDTTornado WatchSPCDakota, Dixon, Thurston7 hr

Nearby

Tornado Watches in Nebraska, 2007Tornado Watches in Kansas, 2007Every tornado watch in 2007

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.