Tornado Watch 164

Issued

Apr 22, 2007, 1:56 PM CDT (18:56 UTC)

Expired

Apr 22, 2007, 9:00 PM CDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

50 kt

The Omaha radar (KOAX), 112 km from the middle of the area, began a volume at 18:56 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.

Two or more tornadoes

40%

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

40%

One or more hailstones of 2 inches or more

10%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 536Apr 22, 10:57 AM CDT
• Mesoscale Discussion 537Apr 22, 12:07 PM CDT
• Mesoscale Discussion 538Apr 22, 1:25 PM CDT
• Mesoscale Discussion 541Apr 22, 5:59 PM CDT

000
WWUS20 KWNS 221902
SEL4  
SPC WW 221902
IAZ000-MOZ000-NEZ000-230200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 164
NWS STORM PREDICTION CENTER NORMAN OK
155 PM CDT SUN APR 22 2007

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

       WESTERN IOWA
       NORTHWEST MISSOURI
       NORTHEAST NEBRASKA

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 155 PM UNTIL 900
PM CDT.

TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 60 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 25 MILES NORTH NORTHWEST OF
STORM LAKE IOWA TO 20 MILES WEST OF CHILLICOTHE MISSOURI.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU4).

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 162...WW 163...

DISCUSSION...TSTMS NOW IN FAR ERN NEB ARE ON LEADING EDGE OF UPR
VORT MAX.  AS UPR SYSTEM CONTINUES ENE...CLEARING/LOW LEVEL MOISTURE
INFLOW SHOULD FURTHER DESTABILIZE REGION IMMEDIATELY AHEAD OF STORMS
SWD INTO NW MO.  WIND PROFILES ARE MOST SUPPORTIVE OF SUPERCELLS IN
SRN PART OF WW...WHERE 50-60 KT MID LEVEL SPEED MAX IS PRESENT ON S
SIDE OF VORT.  IF DESTABILIZATION/CONVERGENCE CAN OVERCOME LOW LEVEL
CIN...A FEW SUPERCELLS WITH HAIL/WIND AND POSSIBLE TORNADOES COULD
FORM.  FARTHER N...DEEP SHEAR IS LESS FAVORABLE FOR SUSTAINED
SUPERCELLS... BUT ENHANCED LOW LEVEL VEERING JUST E VORT-ASSOCIATED
SFC LOW MAY ENHANCE TORNADO POTENTIAL IN NW IA.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 50 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
400. MEAN STORM MOTION VECTOR 22040.


...CORFIDI

Tornado Watches in Iowa, 2007Tornado Watches in Missouri, 2007Tornado Watches in South Dakota, 2007Every tornado watch in 2007

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.