Severe Thunderstorm Watch 653

Issued

Sep 26, 2012, 2:59 PM MDT (20:59 UTC)

Expired

Sep 26, 2012, 10:00 PM MDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Amarillo radar (KAMA), 77 km from the middle of the area, began a volume at 20:59 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

5%

Ten or more severe wind reports

30%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

30%

One or more hailstones of 2 inches or more

20%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 1991Sep 26, 12:50 PM MDT
• Mesoscale Discussion 1996Sep 26, 9:29 PM MDT

479 
WWUS20 KWNS 262100
SEL3  
SPC WW 262100
COZ000-KSZ000-NMZ000-OKZ000-TXZ000-270400-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 653
NWS STORM PREDICTION CENTER NORMAN OK
400 PM CDT WED SEP 26 2012

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

       FAR SOUTHEAST COLORADO
       SOUTHWEST KANSAS
       FAR NORTHEAST NEW MEXICO
       OKLAHOMA PANHANDLE
       TEXAS PANHANDLE

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 400 PM UNTIL
1100 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 70
STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES SOUTH
SOUTHEAST OF AMARILLO TEXAS TO 45 MILES NORTH OF ELKHART KANSAS. 
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU3).

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...CONTINUE...WW 651...WW 652...

DISCUSSION...TSTMS CURRENTLY DEVELOPING ALONG THE RATON MESA ARE
EXPECTED TO INCREASE IN COVERAGE AND INTENSITY AS LOW-LEVEL UPSLOPE
FLOW IS ENHANCED BY THE GLANCING INFLUENCE OF A VORTICITY MAXIMUM
ROTATING AROUND PARENT UPPER LOW.  WHILE THE BOUNDARY LAYER IS NOT
OVERLY MOIST THE COMBINATION OF 45-55 F DEWPOINTS AND STEEP LAPSE
RATES ARE SUPPORTING MODEST INSTABILITY.  MOREOVER...30-35 KT WLY
MIDLEVEL FLOW OVERLAYS ELY SURFACE WINDS...RESULTING IN 40-45 KT OF
DEEP-LAYER SHEAR WHICH WILL SUPPORT SUPERCELLS CAPABLE OF MAINLY
LARGE HAIL AND DAMAGING WINDS.

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 500. MEAN STORM
MOTION VECTOR 28025.


...MEAD

Severe Thunderstorm Watches in Texas, 2012Severe Thunderstorm Watches in Kansas, 2012Severe Thunderstorm Watches in Oklahoma, 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.