Tornado Watch 121

Issued

Apr 10, 2011, 6:20 PM EDT (22:20 UTC)

Expired

Apr 11, 2011, 1:40 AM EDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The NCL Michigan radar (KAPX), 22 km from the middle of the area, began a volume at 22:22 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

40%

One or more gusts of 65 knots or more

20%

Ten or more severe hail reports

40%

One or more hailstones of 2 inches or more

20%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 397Apr 10, 5:51 PM EDT
• Mesoscale Discussion 402Apr 10, 9:55 PM EDT

992 
WWUS20 KWNS 102223
SEL1
SPC WW 102223
MIZ000-LHZ000-LMZ000-110600-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 121
NWS STORM PREDICTION CENTER NORMAN OK
620 PM EDT SUN APR 10 2011

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

       NORTHERN LOWER MICHIGAN
       LAKE HURON
       LAKE MICHIGAN

EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 620 PM UNTIL
200 AM EDT.

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 EAST NORTHEAST OF
PELLSTON MICHIGAN TO 25 MILES SOUTHWEST OF HOUGHTON LAKE
MICHIGAN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).

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 120...

DISCUSSION...CLUSTER OF ELEVATED SUSTAINED TSTMS...NOW OVER
CNTRL/NRN LK MI...EXPECTED TO CONTINUE ENE ACROSS NRN LWR MI THROUGH
REMAINDER OF EVE...WITH ADDITIONAL DEVELOPMENT POSSIBLE AS
ASSOCIATED AREA OF ASCENT INTERACTS WITH SLOWLY-MOVING WARM FRONT
OVER REGION.  GIVEN STRONG DEEP WIND FIELD...AND LIKELIHOOD FOR
FURTHER STRENGTHENING OF WINDS THIS EVE...POTENTIAL WILL EXIST FOR
SUPERCELLS.  IN ADDITION...WITH BOUNDARY LAYER S OF WARM FRONT IN
LWR MI HAVING WARMED THROUGH THE DAY...POTENTIAL ALSO WILL EXIST FOR
STORMS TO BECOME SURFACE BASED.  THUS...A THREAT MAY DEVELOP FOR
ISOLD TORNADOES IN ADDITION TO HAIL AND DMGG WIND.

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
500. MEAN STORM MOTION VECTOR 25045.


...CORFIDI

Tornado Watches in Michigan, 2011Every tornado watch in 2011

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.