Alert archive / Colorado / Tornado Watches in 2002

Tornado Watch 449

June 20, 200218 counties in Colorado

The Storm Prediction Center issued this tornado watch at Jun 20, 2002, 2:30 PM MDT for 18 counties in Colorado. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jun 20, 2002, 2:30 PM MDT (20:30 UTC)
Expired: Jun 20, 2002, 8:00 PM MDT
In force: 6 hr
Issued by: the Storm Prediction Center

Counties Adams County, CO, Arapahoe County, CO, Bent County, CO, Boulder County, CO, Broomfield County, CO, Crowley County, CO, Denver County, CO, Douglas County, CO, El Paso County, CO, Elbert County, CO, Jefferson County, CO, Larimer County, CO, Las Animas County, CO, Lincoln County, CO, Morgan County, CO, Otero County, CO, Pueblo County, CO, Weld County, CO

The radar

The Denver radar (KFTG), 64 km from the middle of the area, began a volume at 20:33 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.

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jun 20, 3:05 PM MDT	Severe Thunderstorm Warning	PUB	Las Animas	2 hr
Jun 20, 5:05 PM MDT	Severe Thunderstorm Warning	PUB	Las Animas	2 hr
Jun 20, 5:25 PM MDT	Flash Flood Warning	BOU	Douglas, Jefferson	95 min

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 8.5 hours before the alert went out and 87 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 89 J/kg
Mixed-layer CIN: -178 J/kg
Mixed-layer LCL: 894 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 19 m²/s²
0-3 km storm-relative helicity: 178 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 202021
SEL9  
SPC WW 202016
COZ000-210200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 449
STORM PREDICTION CENTER NORMAN OK
216 PM MDT THU JUN 20 2002

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

   EASTERN COLORADO                           

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 230 PM UNTIL 800
PM MDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 55 STATUTE MILES EAST AND WEST
OF A LINE FROM 40 MILES NORTH NORTHEAST OF FORT COLLINS COLORADO TO
50 MILES EAST SOUTHEAST OF TRINIDAD COLORADO.

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 447...WW 448...

DISCUSSION...THUNDERSTORMS WILL BEGIN DEVELOPING WITHIN THE NEXT
HOUR OR SO ALONG AND JUST WEST OF THE FOOTHILLS OF CO.  MOIST/SELY
LOW LEVEL FLOW WILL MAINTAIN STRONG INSTABILITY AXIS ACROSS WW AS
VERY STEEP MID LEVEL LAPSE RATES OVERSPREAD THE PLAINS.  WIND
PROFILES WILL REMAIN FAVORABLE FOR SUPERCELLS...WHICH WILL ENHANCE
THE THREAT OF SOME VERY LARGE HAIL STONES.  ISOLATED TORNADOES ARE
ALSO POSSIBLE...ESPECIALLY FROM RIGHT-MOVING SUPERCELLS.


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. 
MEAN STORM MOTION VECTOR 24025.


...EVANS

405,1034 365,1023 365,1042 405,1054

Nearby

Tornado Watches in Colorado, 2002 Every tornado watch in 2002

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; radar from the NEXRAD Level II archive.