Alert archive / Colorado / Severe Thunderstorm Warnings in 1997
Severe Thunderstorm Warning 91, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Jun 25, 1997, 8:06 PM MDT for Boulder County, Jefferson County, Colorado. It was in force for 39 min. 3 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 25, 1997, 8:06 PM MDT (02:06 UTC)
- Expired
- Jun 25, 1997, 8:45 PM MDT
- In force
- 39 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
Counties Boulder County, CO, Jefferson County, CO
The radar
The Denver radar (KFTG), 56 km from the middle of the area, began a volume at 02:06 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 25, 8:20 PM MDT | Hail 0.75 | Louisville, CO | |
| Jun 25, 8:32 PM MDT | Hail 0.75 | Jefferson Co Arpt, CO | |
| Jun 25, 8:36 PM MDT | Hail 0.75 | Jefferson Co Arpt, 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, 2.1 hours before the alert went out and 165 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
- 179 J/kg
- Mixed-layer CIN
- -66 J/kg
- Mixed-layer LCL
- 2584 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 35 m²/s²
- 0-3 km storm-relative helicity
- 175 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
520
WUUS1 KDEN 260209 RRA
SVRDEN
COC013-059-260245-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
806 PM MDT WED JUN 25 1997
THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A SEVERE
THUNDERSTORM WARNING EFFECTIVE UNTIL 845 PM MDT FOR PEOPLE IN THE
FOLLOWING COUNTIES...
IN NORTHEAST COLORADO
SOUTHEASTERN BOULDER AND NORTHEASTERN JEFFERSON
INCLUDING THE FOLLOWING LOCATIONS
NORTHWESTERN ARVADA...BOULDER...WESTERN BROOMFIELD...WESTERN
WESTMINSTER...LAFAYETTE...LOUISVILLE AND SUPERIOR
AT 800 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM 2 MILES SOUTHEAST OF BOULDER...OR ABOUT 23 MILES
NORTHWEST OF DENVER.
THE STORM WAS STATIONARY.
HAIL THREE-QUARTERS OF AN INCH IN DIAMETER WAS REPORTED IN BOULDER
AT 8 PM. EVEN LARGER HAIL UP TO GOLFBALL SIZE IS POSSIBLE...ALONG
WITH BRIEF HEAVY RAINS. IF YOU ARE IN THE PATH OF THE STORM...PUT
YOUR CAR IN A GARAGE AND MOVE TO A SUBSTANTIAL SHELTER.
IF YOU OBSERVE STREET OR SMALL STREAM FLOODING...STAY OUT OF FLOODED
AREAS. DO NOT TRY TO DRIVE THROUGH RUNNING WATER.
REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN DENVER.
LAT...LON 4000 10505 3983 10511 3998 10534 4010 10522
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 25, 6:10 PM MDT, 1 hour 56 minutes before
COZ036-038>050-260200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 610 PM MDT WED JUN 25 1997 ...PARTS OF TORNADO WATCH CANCELLED... PART OF THE TORNADO WATCH ISSUED WEDNESDAY AFTERNOON HAS BEEN CANCELLED. THE COUNTIES IN NORTHEAST COLORADO NO LONGER IN THE TORNADO WATCH ARE EASTERN BOULDER...EASTERN JEFFERSON...DOUGLAS... WESTERN ARAPAHOE...DENVER...WESTERN ADAMS...WELD...AND EASTERN LARIMER. COUNTIES IN NORTHEAST COLORADO STILL UNDER TORNADO WATCH NUMBER 523 ARE...CENTRAL AND EASTERN ADAMS AND ARAPAHOE...LINCOLN...WASHINGTON ...LOGAN...MORGAN...PHILLIPS AND SEDGWICK. PEOPLE IN THESE AREAS SHOULD REMAIN ALERT TO CHANGING WEATHER CONDITIONS THROUGH 8 PM. ET
Local storm report, Jun 25, 6:32 PM MDT, 1 hour 34 minutes before
LOCAL STORM REPORT...CORRECTED FORMAT
NATIONAL WEATHER SERVICE DENVER CO
632 PM MDT THU JUN 25 1997
...PRELIMINARY STORM REPORT FOR JUN 25 1997...
TIME(MDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
414 PM 3 E JULESBURG CO 1.00 INCH HAIL
06/25/97 SEDGWICK
422 PM 6 S JULESBURG CO 1.75 INCH HAIL
06/25/97 SEDGWICK
450 PM STERLING CO FLASH FLOODING
06/25/97 LOGAN CARS FLOATING IN WATER
RAYLocal storm report, Jun 25, 6:33 PM MDT, 1 hour 33 minutes before
LOCAL STORM REPORT...CORRECTED FORMAT
NATIONAL WEATHER SERVICE DENVER CO
632 PM MDT THU JUN 25 1997
...PRELIMINARY STORM REPORT FOR JUN 25 1997...
TIME(MDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
414 PM 3 E JULESBURG CO 1.00 INCH HAIL
06/25/97 SEDGWICK
422 PM 6 S JULESBURG CO 1.75 INCH HAIL
06/25/97 SEDGWICK
450 PM STERLING CO FLASH FLOODING
06/25/97 LOGAN CARS FLOATING IN WATER
RAYLocal storm report, Jun 25, 6:34 PM MDT, 1 hour 32 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
634 PM MDT THU JUN 25 1997
...PRELIMINARY STORM REPORT FOR JUN 25 1997...
TIME(MDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
414 PM 3 E JULESBURG CO 1.00 INCH HAIL
06/25/97 SEDGWICK
422 PM 6 S JULESBURG CO 1.75 INCH HAIL
06/25/97 SEDGWICK
450 PM STERLING CO FLASH FLOODING
06/25/97 LOGAN CARS FLOATING IN WATER
RAYSpecial weather statement, Jun 25, 8:00 PM MDT, 6 minutes before
COZ036-038>050-260200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 800 PM MDT WED JUN 25 1997 ...REST OF TORNADO WATCH EXPIRES... THE REMAINDER OF TORNADO WATCH NUMBER 523...WHICH WAS IN EFFECT FOR CENTRAL AND EASTERN ADAMS...CENTRAL AND EASTERN ARAPAHOE...LINCOLN ...WASHINGTON...LOGAN...MORGAN...PHILLIPS AND SEDGWICK COUNTIES HAS EXPIRED AT 8 PM. SEVERE WEATHER IS NO LONGER ANTICIPATED IN THESE AREAS. ET
Special weather statement, Jun 25, 8:04 PM MDT, 2 minutes before
COZ036-038>050-260200- SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE DENVER CO 800 PM MDT WED JUN 25 1997 ...REST OF TORNADO WATCH EXPIRES... THE REMAINDER OF TORNADO WATCH NUMBER 523...WHICH WAS^ IN EFFECT FOR CENTRAL AND EASTERN ADAMS...CENTRAL AND EASTERN ARAPAHOE...LINCOLN ...WASHINGTON...LOGAN...MORGAN...PHILLIPS AND SEDGWICK COUNTIES HAS EXPIRED AT 8 PM. SEVERE WEATHER IS NO LONGER ANTICIPATED IN THESE AREAS. ET
The office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 25, 8:38 PM MDT | Severe Thunderstorm Warning | BOU | Adams, Boulder, Jefferson | 37 min |
| Jun 25, 8:38 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 37 min |
| Jun 25, 8:53 PM MDT | Severe Thunderstorm Warning | BOU | Denver | 37 min |
| Jun 25, 9:01 PM MDT | Severe Thunderstorm Warning | BOU | Boulder, Weld | 44 min |
| Jun 25, 9:26 PM MDT | Severe Thunderstorm Warning | BOU | Weld | 34 min |
Nearby
Severe Thunderstorm Warnings in Colorado, 1997Every severe thunderstorm warning in 1997
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.