Severe Thunderstorm Watch 474

Issued

Jul 6, 2012, 2:58 PM CDT (19:58 UTC)

Expired

Jul 6, 2012, 8:15 PM CDT

In force

5 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Memphis radar (KNQA), 126 km from the middle of the area, began a volume at 19:58 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

10%

One or more EF2 to EF5 tornadoes

2%

Ten or more severe wind reports

60%

One or more gusts of 65 knots or more

20%

Ten or more severe hail reports

20%

One or more hailstones of 2 inches or more

10%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 1417Jul 6, 12:42 PM CDT
• Mesoscale Discussion 1418Jul 6, 2:36 PM CDT
• Mesoscale Discussion 1422Jul 6, 6:15 PM CDT

143 
WWUS20 KWNS 062000
SEL4  
SPC WW 062000
ALZ000-MSZ000-TNZ000-070200-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 474
NWS STORM PREDICTION CENTER NORMAN OK
300 PM CDT FRI JUL 6 2012

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

       NORTHWEST ALABAMA
       NORTHERN MISSISSIPPI
       WESTERN AND MIDDLE TENNESSEE

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 300 PM UNTIL 900
PM 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 85
STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES WEST
NORTHWEST OF NASHVILLE TENNESSEE TO 35 MILES SOUTH SOUTHEAST OF
OXFORD MISSISSIPPI.  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.

DISCUSSION...STRONG/SEVERE STORMS APPEAR TO BE ORGANIZING IN A BAND
FROM PARTS OF TN INTO NWRN AL/NERN MS...ALONG THE LEADING EDGE OF
MID/UPPER LEVEL DRYING EVIDENT IN WATER VAPOR IMAGERY.  LOW LEVEL
AIR MASS IS HOT WITH TEMPERATURES NEAR 100...AND WITH DEW POINTS IN
THE 65-70 RANGE...STRONG INSTABILITY COUPLED WITH A DEEP
SURFACE-BASED WELL-MIXED LAYER WILL ENHANCE POTENTIAL FOR DAMAGING
WIND GUSTS.  ACTIVITY IS EXPECTED TO SPREAD SWD/SWWD THROUGH THE
EVENING BEFORE GRADUALLY WEAKENING AROUND SUNSET.

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 04020.


...WEISS

Severe Thunderstorm Watches in Tennessee, 2012Severe Thunderstorm Watches in Mississippi, 2012Severe Thunderstorm Watches in Alabama, 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.