Alert archive / Colorado / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 12, NWS Denver/Boulder, CO

May 11, 1998Arapahoe County, Elbert County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 11, 1998, 2:49 PM MDT for Arapahoe County, Elbert County, Colorado. It was in force for 41 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued: May 11, 1998, 2:49 PM MDT (20:49 UTC)
Expired: May 11, 1998, 3:30 PM MDT
In force: 41 min
Issued by: NWS Denver/Boulder, CO
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Arapahoe County, CO, Elbert County, CO

The radar

The Denver radar (KFTG), 24 km from the middle of the area, began a volume at 20:48 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.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 8.8 hours before the alert went out and 113 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: 602 J/kg
Mixed-layer CIN: -42 J/kg
Mixed-layer LCL: 578 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 25 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

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

049 
WUUS1 KDEN 112052 RRA
SVRDEN
COC005-039-112130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
249 PM MDT MON MAY 11 1998

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
     NORTHWESTERN ELBERT COUNTY IN EAST CENTRAL COLORADO
     CENTRAL ARAPAHOE COUNTY IN NORTHEAST COLORADO

* UNTIL 330 PM MDT

* AT 242 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 17 MILES SOUTHWEST OF COUNTRY GARDENS...OR
  ABOUT 28 MILES SOUTHEAST OF DENVER...MOVING NORTHEAST AT 20 MILES
  PER HOUR.

* LOCATIONS IN THE WARNING INCLUDE COUNTRY GARDENS

IF SEVERE WEATHER APPROACHES YOUR AREA...GO INSIDE A STURDY SHELTER
AWAY FROM CREEK BEDS AND OTHER FLOOD-PRONE AREAS. REMEMBER...A SEVERE
THUNDERSTORM CAN PRODUCE LARGE DAMAGING HAIL...DAMAGING WINDS OVER 60
MPH...DEADLY LIGHTNING...AND VERY HEAVY RAIN.

ENTREKIN

LAT...LON 3954 10472 3939 10452 3964 10415 3976 10439

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, May 11, 11:15 AM MDT, 3 hours 34 minutes before

COZ030-032>050-120600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
1115 AM MDT MON MAY 11 1998

THIS OUTLOOK PERTAINS TO THE FOLLOWING COLORADO COUNTIES

ADAMS     ARAPAHOE     BOULDER   CLEAR CREEK   DENVER       DOUGLAS
ELBERT    GILPIN       GRAND     JACKSON       JEFFERSON    LARIMER
LINCOLN   LOGAN        MORGAN    PARK          PHILLIPS     SEDGWICK
SUMMIT    WASHINGTON   WELD

SYNOPSIS...AN UPPER LEVEL TROUGH WILL MOVE ACROSS THE AREA THIS
AFTERNOON AND EARLY THIS EVENING AS AN ASSOCIATED SURFACE LOW
PRESSURE CENTER OVER EAST CENTRAL COLORADO AT MIDDAY MOVES NORTHEAST
INTO CENTRAL NEBRASKA TONIGHT.  THE AIR MASS OVER NORTHEASTERN
COLORADO WILL REMAIN RELATIVELY MOIST AND UNSTABLE THROUGH TONIGHT.

WIDELY SCATTERED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL FORM
OVER THE MOUNTAINS BY MIDDAY AND MOVE TO THE NORTHEAST OVER THE
FRONT RANGE URBAN CORRIDOR AND NORTHEASTERN PLAINS ON MODERATE
SOUTHWESTERLY WINDS ALOFT.  ONE OR TWO THUNDERSTORMS MAY BE SEVERE
WITH LARGE HAIL AND POSSIBLE DAMAGING WINDS THIS AFTERNOON AND
EVENING MAINLY NEAR THE NORTHERN BORDER OF COLORADO.

SPOTTER ACTIVATION MAY BE NEEDED MAINLY NORTH OF METRO DENVER.

GARD...WSFO DENVER

Nearby

Severe Thunderstorm Warnings in Colorado, 1998 Every severe thunderstorm warning in 1998

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.