Alert archive / Colorado / Severe Thunderstorm Warnings in 1998
Severe Thunderstorm Warning 15, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 11, 1998, 7:54 PM MDT for 5 counties in Colorado. It was in force for 36 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
- May 11, 1998, 7:54 PM MDT (01:54 UTC)
- Expired
- May 11, 1998, 8:30 PM MDT
- In force
- 36 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
Counties Adams County, CO, Arapahoe County, CO, Denver County, CO, Douglas County, CO, Jefferson County, CO
The radar
The Denver radar (KFTG), 45 km from the middle of the area, began a volume at 01:54 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 |
|---|---|---|---|
| May 11, 8:15 PM MDT | Hail 1 | Littleton, CO | |
| May 11, 8:15 PM MDT | Hail 0.75 | Parker, 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, 1.9 hours before the alert went out and 156 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
- 442 J/kg
- Mixed-layer CIN
- -57 J/kg
- Mixed-layer LCL
- 2057 m above ground
- 0-6 km bulk shear
- 72 kt
- 0-1 km storm-relative helicity
- 64 m²/s²
- 0-3 km storm-relative helicity
- 212 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.4
The text
As transmitted, in the capitals the NWS used until 2016.
698
WUUS1 KDEN 120157 RRA
SVRDEN
COC001-005-031-035-059-120230-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
754 PM MDT MON MAY 11 1998
THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
SOUTHWESTERN ADAMS COUNTY IN NORTHEAST COLORADO
WESTERN ARAPAHOE COUNTY IN NORTHEAST COLORADO
SOUTHWESTERN DENVER COUNTY IN NORTHEAST COLORADO
NORTHERN DOUGLAS COUNTY IN NORTHEAST COLORADO
EAST CENTRAL JEFFERSON COUNTY IN NORTHEAST COLORADO
* UNTIL 830 PM MDT
* AT 748 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM 3 MILES NORTHWEST OF CHATFIELD RESERVOIR...OR
ABOUT 14 MILES SOUTHWEST OF DENVER...MOVING EAST AT 20 MILES PER
HOUR.
* LOCATIONS IN THE WARNING INCLUDE WESTERN AURORA...COMMERCE CITY...
DENVER...ENGLEWOOD...SOUTHERN GOLDEN...LAKEWOOD...LITTLETON...WHEAT
RIDGE...BEVERLY HILLS...CHATFIELD RESERVOIR...GREENWOOD VILLAGE...
HIGHLANDS RANCH...IDLEDALE...LOUVIERS...MORRISON...PARKER...RED
ROCKS PARK...SHERIDAN AND SURREY RIDGE
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 3970 10527 3944 10507 3950 10468 3982 10487What 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
Local storm report, May 11, 5:05 PM MDT, 2 hours 49 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
505 PM MDT MON MAY 11 1998
...PRELIMINARY STORM REPORT FOR MAY 10 1998...
TIME(MDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0355 PM WIGGINS CO 0.75 INCH HAIL
05/10/98 MORGAN
ENTREKINLocal storm report, May 11, 5:05 PM MDT, 2 hours 49 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
505 PM MDT MON MAY 11 1998
...PRELIMINARY STORM REPORT FOR MAY 10 1998...
TIME(MDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0355 PM WIGGINS CO 0.75 INCH HAIL
05/10/98 MORGAN
ENTREKINLocal storm report, May 11, 5:15 PM MDT, 2 hours 39 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
515 PM MDT MON MAY 11 1998 ...CORRECTION FOR DATE...
...PRELIMINARY STORM REPORT FOR MAY 11 1998...
TIME(MDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0355 PM WIGGINS CO 0.75 INCH HAIL
05/11/98 MORGAN
ENTREKINLocal storm report, May 11, 5:15 PM MDT, 2 hours 39 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
515 PM MDT MON MAY 11 1998 ...CORRECTION FOR DATE...
...PRELIMINARY STORM REPORT FOR MAY 11 1998...
TIME(MDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0355 PM WIGGINS CO 0.75 INCH HAIL
05/11/98 MORGAN
ENTREKINThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 11, 7:07 PM MDT | Severe Thunderstorm Warning | BOU | Lincoln | 38 min |
| May 11, 7:36 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Arapahoe, Denver | 34 min |
| May 11, 8:27 PM MDT | Severe Thunderstorm Warning | BOU | Arapahoe, Douglas, Elbert | 33 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.