Alert archive / Colorado / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 95, NWS Denver/Boulder, CO

June 22, 1998Morgan County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 22, 1998, 6:12 PM MDT for Morgan County, Colorado. It was in force for 48 min. 1 report came from 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, with what was reported inside it.

The facts

Issued
Jun 22, 1998, 6:12 PM MDT (00:12 UTC)
Expired
Jun 22, 1998, 7:00 PM MDT
In force
48 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Morgan County, CO

The radar

The Denver radar (KFTG), 68 km from the middle of the area, began a volume at 00:14 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.

What was reported inside it

TimeReportWhereRemark
Jun 22, 6:51 PM MDTHail 0.75Ft Morgan, CO

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 0.2 hours before the alert went out and 59 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 00:00Z on 1998-06-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 411 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 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 00:00Z on 1998-06-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 77 square meters per square second.193958Sfc1 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
411 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
2892 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
77 m²/s²
0-3 km storm-relative helicity
121 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

Open this sounding in Storm Lab

The text

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

050 
WUUS1 KDEN 230013 RRA
SVRDEN
COC087-230100-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
612 PM MDT MON JUN 22 1998

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
     SOUTH CENTRAL MORGAN COUNTY IN NORTHEAST COLORADO

* UNTIL 700 PM MDT

* AT 608 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 4 MILES NORTHWEST OF ADENA...OR ABOUT 14 MILES
  SOUTHWEST OF FORT MORGAN...MOVING EAST AT 20 MILES PER HOUR.

* LOCATIONS IN THE WARNING INCLUDE...ADENA...ADENA SCHOOL AND
  TWELVE-MILE CORNER

VERY LARGE HAIL AND HEAVY RAIN IS POSSIBLE WITH THIS SEVERE 
THUNDERSTORM. IF YOU ARE IN THE PATH OF THE STORM...PUT YOUR CAR IN 
A GARAGE AND MOVE TO A SUBSTANTIAL SHELTER.  DO NOT DRIVE THROUGH 
RUNNING WATER.

LAT...LON 4014 10395 3999 10396 3999 10371 4019 10371

GIMMESTAD

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, Jun 22, 4:45 PM MDT, 1 hour 27 minutes before
COZ030-032>050-230600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
445 PM MDT MON JUN 22 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:  THE FIRST THUNDERSTORM OF THE DAY HAS CREATED A WIND
SHIFT LINE ACROSS THE DENVER METRO AREA.  THIS HAS LESSENED THE
CHANCE OF SEVERE WEATHER FARTHER NORTH IN THE GREELEY AND FORT
COLLINS AREA.  THE MAIN AREA FOR THUNDERSTORM DEVELOPMENT FOR THE
REST OF THE AFTERNOON WILL BE IN THE AREA BETWEEN DENVER AND LAST
CHANCE.

FARTHER EAST...THE AIRMASS REMAINS MOIST AND UNSTABLE.  ADDITIONAL
THUNDERSTORM DEVELOPMENT IS EXPECTED THIS EVENING FROM LAST CHANCE
AND NEW RAYMER EAST.  HAIL IN THE ONE TO TWO INCH DIAMETER RANGE
WILL BE THE MAIN FEATURE OF STORMS THIS EVENING...BUT DAMAGING
WINDS...TORNADOES...AND HEAVY RAIN ARE ALSO POSSIBLE.

AMATEUR RADIO SPOTTERS HAVE BEEN ACTIVATED IN THE DENVER AREA.  YOU
CAN REPORT SEVEVRE WEATHER TO YOUR LOCAL LAW ENFORCEMENT OFFICIALS
WHO WILL RELAY THE REPORT TO THE NATIONAL WEATHER SERVICE.

GIMMESTAD
Special weather statement, Jun 22, 4:45 PM MDT, 1 hour 27 minutes before
COZ030-032>050-230600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
445 PM MDT MON JUN 22 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:  THE FIRST THUNDERSTORM OF THE DAY HAS CREATED A WIND
SHIFT LINE ACROSS THE DENVER METRO AREA.  THIS HAS LESSENED THE
CHANCE OF SEVERE WEATHER FARTHER NORTH IN THE GREELEY AND FORT
COLLINS AREA.  THE MAIN AREA FOR THUNDERSTORM DEVELOPMENT FOR THE
REST OF THE AFTERNOON WILL BE IN THE AREA BETWEEN DENVER AND LAST
CHANCE.

FARTHER EAST...THE AIRMASS REMAINS MOIST AND UNSTABLE.  ADDITIONAL
THUNDERSTORM DEVELOPMENT IS EXPECTED THIS EVENING FROM LAST CHANCE
AND NEW RAYMER EAST.  HAIL IN THE ONE TO TWO INCH DIAMETER RANGE
WILL BE THE MAIN FEATURE OF STORMS THIS EVENING...BUT DAMAGING
WINDS...TORNADOES...AND HEAVY RAIN ARE ALSO POSSIBLE.

AMATEUR RADIO SPOTTERS HAVE BEEN ACTIVATED IN THE DENVER AREA.  YOU
CAN REPORT SEVEVRE WEATHER TO YOUR LOCAL LAW ENFORCEMENT OFFICIALS
WHO WILL RELAY THE REPORT TO THE NATIONAL WEATHER SERVICE.

GIMMESTAD

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 22, 7:00 PM MDTSevere Thunderstorm WarningBOUMorgan45 min
Jun 22, 8:40 PM MDTSevere Thunderstorm WarningBOUWashington50 min
Jun 22, 9:11 PM MDTTornado WarningBOUWashington34 min
Jun 22, 10:47 PM MDTSevere Thunderstorm WarningBOUWeld43 min
Jun 22, 11:27 PM MDTFlash Flood WarningBOUWeld3 hr
Jun 22, 11:31 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld44 min
Jun 23, 12:14 AM MDTSevere Thunderstorm WarningBOUMorgan46 min
Jun 23, 12:58 AM MDTSevere Thunderstorm WarningBOUMorgan, Washington47 min

Nearby

Severe Thunderstorm Warnings in Colorado, 1998Every 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.