Severe Thunderstorm Watch 464

Issued

Jul 4, 2012, 7:31 PM CDT (00:31 UTC)

Expired

Jul 5, 2012, 12:11 AM CDT

In force

5 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Duluth radar (KDLH), 94 km from the middle of the area, began a volume at 00:31 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.

Two or more tornadoes

20%

One or more EF2 to EF5 tornadoes

10%

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

20%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 1392Jul 4, 3:57 PM CDT

662 
WWUS20 KWNS 050036
SEL4
SPC WW 050036
MNZ000-WIZ000-LSZ000-050800-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 464
NWS STORM PREDICTION CENTER NORMAN OK
730 PM CDT WED JUL 4 2012

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

       NORTHERN AND CENTRAL MINNESOTA
       NORTHWEST WISCONSIN
       LAKE SUPERIOR

EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 730 PM
UNTIL 300 AM CDT.

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

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 50
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 35 MILES WEST
SOUTHWEST OF BEMIDJI MINNESOTA TO
25 MILES SOUTH OF IRONWOOD
MICHIGAN.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU4).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

OTHER WATCH INFORMATION...THIS SEVERE THUNDERSTORM WATCH REPLACES
SEVERE THUNDERSTORM WATCH NUMBER 460. WATCH NUMBER 460 WILL NOT
BE IN EFFECT AFTER 730 PM CDT. CONTINUE...WW 461...WW 462...WW
463...

DISCUSSION...SCTD CLUSTERS OF STRONG TO SVR TSTMS...MOST SLIGHTLY
ELEVATED...EXPECTED TO PERSIST ALONG AND N OF STALLED OUTFLOW
BOUNDARY THAT ATTM EXTENDS ROUGHLY ESE FROM NEAR DETROIT LAKES MN
/DTL/ TO S OF HAYWARD WI /HYR/.  LARGE SCALE FORCING FOR ASCENT WILL
REMAIN WEAK...BUT POSSIBLY AUGMENTED BY DISTURBANCE IN WV IMAGERY
JUST TOPPING LARGE UPR RIDGE.  NEVERTHELESS...DEGREE OF
BUOYANCY...DUE TO BOTH DEEP EML AND RICH PBL MOISTURE...SUGGESTS
POTENTIAL FOR LARGE HAIL/DMGG WIND GIVEN EXPECTED NOCTURNAL INCREASE
IN 25 KT SSWLY LLJ.
IN ADDITION...A NON-ZERO THREAT WILL EXIST FOR A TORNADO OR TWO IF
STORMS PERSIST IN IMMEDIATE VICINITY OF STALLED BOUNDARY.  THIS
THREAT WOULD APPEAR TO BE GREATEST FROM NEAR BEMIDJI /BJI/ ESE TO S
OF DULUTH /DLH/.  IF IT APPEARS THAT SUCH A SCENARIO WILL BECOME
MORE LIKELY LATER THIS EVENING IN RESPONSE TO STRENGTHENING LOW LVL
FLOW...A SMALL PORTION OF THE WATCH MAY REQUIRE UPGRADE TO TORNADO.

AVIATION...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 550. MEAN STORM
MOTION VECTOR 29030.


...CORFIDI

Severe Thunderstorm Watches in Minnesota, 2012Severe Thunderstorm Watches in Wisconsin, 2012Every severe thunderstorm watch in 2012

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.