Alert archive / Colorado / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 75, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 7, 1998, 6:39 PM MDT for Logan County, Colorado. It was in force for 51 min. 2 reports 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 7, 1998, 6:39 PM MDT (00:39 UTC)
- Expired
- Jun 7, 1998, 7:30 PM MDT
- In force
- 51 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
County Logan County, CO
The radar
The Cheyenne radar (KCYS), 144 km from the middle of the area, began a volume at 00:41 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Jun 7, 6:50 PM MDT | Hail 0.75 | Sterling, CO | |
| Jun 7, 7:00 PM MDT | Hail 1.75 | Iliff, 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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jun 7, 1:15 PM MDT | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Denver, CO (KDNR), launched 00:00Z, 0.7 hours before the alert went out and 100 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.
- Mixed-layer CAPE
- 438 J/kg
- Mixed-layer CIN
- -175 J/kg
- Mixed-layer LCL
- 2270 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 33 m²/s²
- 0-3 km storm-relative helicity
- 106 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.9
The text
As transmitted, in the capitals the NWS used until 2016.
055
WUUS1 KDEN 080040 RRA
SVRDEN
COC075-080130-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
639 PM MDT SUN JUN 7 1998
THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
CENTRAL LOGAN COUNTY IN NORTHEAST COLORADO
* UNTIL 730 PM MDT
* AT 634 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM 4 MILES SOUTHWEST OF PADRONI...OR ABOUT 5 MILES
NORTH OF STERLING...MOVING NORTHEAST AT 20 MILES PER HOUR.
* LOCATIONS IN THE WARNING INCLUDE...STERLING...ILIFF...NORTH
STERLING RESERVOIR AND PADRONI
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.
A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 800 PM MDT FOR
EASTERN COLORADO.
LAT...LON 4076 10330 4065 10319 4076 10297 4091 10311
COOPERWhat 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 7, 3:05 PM MDT, 3 hours 34 minutes before
COZ030-032>050-080600- SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO NATIONAL WEATHER SERVICE DENVER CO 305 PM MDT SUN JUN 7 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: A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR THE NORTHEAST COLORADO PLAINS UNTIL 8 PM THIS EVENING. AT ABOUT 130 PM...A LINE OF SHOWERS AND THUNDERSTORMS HAD DEVELOPED FROM WESTERN ARAPAHOE COUNTY THROUGH CENTRAL AND NORTHERN MORGAN COUNTY. THESE STORMS PRODUCED MAINLY RAIN. CONDITIONS ACROSS NORTHEAST COLORADO REMAIN FAVORABLE FOR STRONG TO SEVERE THUNDERSTORM DEVELOPMENT. STRONG WINDS ALOFT MAY HELP PRODUCE DAMAGING WINDS FROM THUNDERSTORM OUTFLOWS. LOCATIONS ALONG THE I-25 CORRIDOR AND INTO WELD COUNTY WILL FACE THE GREATEST THREAT OF DAMAGE FROM GUSTY WINDS. AREAS EAST OF A LINE FROM BYERS TO FORT MORGAN TO STERLING WILL CONTINUE TO HAVE THE THREAT OF LARGE HAIL FROM THUNDERSTORMS THAT DEVELOP. A FEW TORNADOES ARE ALSO STILL POSSIBLE FROM THESE STORMS. STORMS THAT HAVE DEVELOPED SO FAR THIS AFTERNOON HAVE BEEN MOVING NORTHEASTWARD AT ABOUT 20 MPH. SPOTTERS HAVE BEEN ACTIVATED TO MONITOR STORM DEVELOPMENT. DANKERS
Special weather statement, Jun 7, 3:05 PM MDT, 3 hours 34 minutes before
COZ030-032>050-080600- SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO NATIONAL WEATHER SERVICE DENVER CO 305 PM MDT SUN JUN 7 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: A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR THE NORTHEAST COLORADO PLAINS UNTIL 8 PM THIS EVENING. AT ABOUT 130 PM...A LINE OF SHOWERS AND THUNDERSTORMS HAD DEVELOPED FROM WESTERN ARAPAHOE COUNTY THROUGH CENTRAL AND NORTHERN MORGAN COUNTY. THESE STORMS PRODUCED MAINLY RAIN. CONDITIONS ACROSS NORTHEAST COLORADO REMAIN FAVORABLE FOR STRONG TO SEVERE THUNDERSTORM DEVELOPMENT. STRONG WINDS ALOFT MAY HELP PRODUCE DAMAGING WINDS FROM THUNDERSTORM OUTFLOWS. LOCATIONS ALONG THE I-25 CORRIDOR AND INTO WELD COUNTY WILL FACE THE GREATEST THREAT OF DAMAGE FROM GUSTY WINDS. AREAS EAST OF A LINE FROM BYERS TO FORT MORGAN TO STERLING WILL CONTINUE TO HAVE THE THREAT OF LARGE HAIL FROM THUNDERSTORMS THAT DEVELOP. A FEW TORNADOES ARE ALSO STILL POSSIBLE FROM THESE STORMS. STORMS THAT HAVE DEVELOPED SO FAR THIS AFTERNOON HAVE BEEN MOVING NORTHEASTWARD AT ABOUT 20 MPH. SPOTTERS HAVE BEEN ACTIVATED TO MONITOR STORM DEVELOPMENT. DANKERS
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 8, 2:25 AM MDT | Severe Thunderstorm Warning | BOU | Weld | 35 min |
| Jun 8, 3:00 AM MDT | Severe Thunderstorm Warning | BOU | Logan, Weld | 40 min |
| Jun 8, 3:02 AM MDT | Severe Thunderstorm Warning | BOU | Logan, Weld | 38 min |
| Jun 8, 4:11 PM MDT | Severe Thunderstorm Warning | BOU | Boulder, Jefferson | 49 min |
| Jun 8, 4:59 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Denver, Jefferson | 46 min |
| Jun 8, 5:32 PM MDT | Severe Thunderstorm Warning | BOU | Douglas, Jefferson | 28 min |
| Jun 8, 5:59 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe, Denver, Douglas, Jefferson | 31 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.