Tornado Watch 238

Issued

Apr 27, 2011, 4:36 PM EDT (20:36 UTC)

Expired

Apr 28, 2011, 1:00 AM EDT

In force

8 hr

Issued by

the Storm Prediction Center

Particularly dangerous situation

Yes

Largest hail expected

3 in

Strongest gust expected

70 kt

The Nashville radar (KOHX), 54 km from the middle of the area, began a volume at 20:36 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

90%

One or more EF2 to EF5 tornadoes

80%

Ten or more severe wind reports

90%

One or more gusts of 65 knots or more

80%

Ten or more severe hail reports

80%

One or more hailstones of 2 inches or more

70%

Six or more combined severe hail and wind reports

90%

• Mesoscale Discussion 621Apr 27, 12:39 PM EDT
• Mesoscale Discussion 623Apr 27, 1:08 PM EDT
• Mesoscale Discussion 625Apr 27, 2:03 PM EDT
• Mesoscale Discussion 626Apr 27, 2:05 PM EDT
• Mesoscale Discussion 627Apr 27, 3:22 PM EDT
• Mesoscale Discussion 629Apr 27, 3:56 PM EDT
• Mesoscale Discussion 630Apr 27, 4:06 PM EDT
• Mesoscale Discussion 636Apr 27, 6:38 PM EDT
• Mesoscale Discussion 637Apr 27, 6:41 PM EDT
• Mesoscale Discussion 648Apr 28, 12:09 AM EDT

010 
WWUS20 KWNS 272037
SEL8
SPC WW 272037
TNZ000-280500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 238
NWS STORM PREDICTION CENTER NORMAN OK
335 PM CDT WED APR 27 2011

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

       MIDDLE AND EASTERN TENNESSEE

EFFECTIVE THIS WEDNESDAY AFTERNOON FROM 335 PM UNTIL MIDNIGHT CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

DESTRUCTIVE TORNADOES...LARGE HAIL TO 3 INCHES IN DIAMETER...
THUNDERSTORM WIND GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE
POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 50 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 70 MILES WEST SOUTHWEST OF
NASHVILLE TENNESSEE TO 25 MILES EAST OF KNOXVILLE TENNESSEE.  FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU8).

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 232...WW 233...WW
234...WW 235...WW 236...

DISCUSSION...A VERY UNSTABLE AIRMASS IS EXPECTED TO GRADUALLY
DEVELOP NORTHWARD INTO TN THIS EVENING IN THE WAKE OF A MORNING MCS.
WITHIN AN INCREASINGLY SHEARED ENVIRONMENT...ACCENTUATED BY
LONG/CURVING LOW LEVEL HODOGRAPHS...SUPERCELLS CAPABLE OF TORNADOES
/SOME STRONG/ WILL BE AN INCREASING/MORE WIDESPREAD CONCERN INTO
THIS EVENING.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 24040.


...GUYER/HART

Tornado Watches in Tennessee, 2011Tornado Watches in North Carolina, 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.