Alert archive / Colorado / Severe Thunderstorm Watches in 2003

Severe Thunderstorm Watch 421

May 23, 200311 counties in Colorado

The Storm Prediction Center issued this severe thunderstorm watch at May 23, 2003, 2:30 PM MDT for 11 counties in Colorado. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 23, 2003, 2:30 PM MDT (20:30 UTC)
Expired
May 23, 2003, 7:00 PM MDT
In force
5 hr
Issued by
the Storm Prediction Center

Counties Adams County, CO, Arapahoe County, CO, Denver County, CO, Douglas County, CO, El Paso County, CO, Elbert County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Washington County, CO, Weld County, CO

Warnings issued inside it

2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 23, 3:39 PM MDTSevere Thunderstorm WarningPUBEl Paso51 min
May 23, 4:22 PM MDTSevere Thunderstorm WarningPUBEl Paso38 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 8.5 hours before the alert went out and 83 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2003-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 24 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2003-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
24 J/kg
Mixed-layer CIN
-367 J/kg
Mixed-layer LCL
1770 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
60 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WWUS20 KWNS 232028
SEL1  
SPC WW 232030
COZ000-240100-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 421 
NWS STORM PREDICTION CENTER NORMAN OK 
230 PM MDT FRI MAY 23 2003

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

       NORTHEASTERN COLORADO

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 230 PM UNTIL 700
PM MDT.

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 ALONG AND 60 STATUTE MILES
EAST AND WEST OF A LINE FROM 40 MILES EAST SOUTHEAST OF COLORADO
SPRINGS COLORADO TO 60 MILES NORTH NORTHWEST OF AKRON COLORADO.

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 419...WW 420...


DISCUSSION...AS SHORTWAVE TROUGH MOVES SEWD INTO THE AREA...STORMS
ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSIFY.  AIR MASS IS
MODERATELY UNSTABLE AND STRONG DIRECTIONAL SHEAR WILL BE FAVORABLE
FOR SUPERCELLS WITH 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 550. MEAN STORM
MOTION VECTOR 32015.


...IMY

383,1050 405,1044 405,1023 383,1025 

WWUS20 KWNS 232028
SEL1  
SPC WW 232030
COZ000-240100-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 421 
NWS STORM PREDICTION CENTER NORMAN OK 
230 PM MDT FRI MAY 23 2003

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

       NORTHEASTERN COLORADO

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 230 PM UNTIL 700
PM MDT.

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 ALONG AND 60 STATUTE MILES
EAST AND WEST OF A LINE FROM 40 MILES EAST SOUTHEAST OF COLORADO
SPRINGS COLORADO TO 60 MILES NORTH NORTHWEST OF AKRON COLORADO.

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 419...WW 420...


DISCUSSION...AS SHORTWAVE TROUGH MOVES SEWD INTO THE AREA...STORMS
ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSIFY.  AIR MASS IS
MODERATELY UNSTABLE AND STRONG DIRECTIONAL SHEAR WILL BE FAVORABLE
FOR SUPERCELLS WITH 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 550. MEAN STORM
MOTION VECTOR 32015.


...IMY

383,1050 405,1044 405,1023 383,1025

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 23, 11:41 AM MDTMesoscale DiscussionSPCCrowley, Elbert, El Paso, Las Animas, Lincoln, Otero and 1 more3 hr
May 23, 1:54 PM MDTMesoscale DiscussionSPCAdams, Arapahoe, Denver, Logan, Morgan, Phillips and 4 more2 hr
May 23, 1:55 PM MDTSevere Thunderstorm WatchSPCBaca, Bent, Crowley, Kiowa, Las Animas, Otero and 2 more5 hr
May 23, 4:32 PM MDTMesoscale DiscussionSPCBaca, Bent, Crowley, Kiowa, Las Animas, Otero and 2 more88 min
May 23, 4:54 PM MDTMesoscale DiscussionSPCAdams, Arapahoe, Denver, Douglas, Elbert, El Paso and 5 more96 min

Nearby

Severe Thunderstorm Watches in Colorado, 2003Every severe thunderstorm watch in 2003

Sources

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.