Alert archive / Colorado / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 29, NWS Denver/Boulder, CO

May 21, 1998Morgan County, Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 21, 1998, 8:01 PM MDT for Morgan County, Weld County, Colorado. It was in force for 39 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
May 21, 1998, 8:01 PM MDT (02:01 UTC)
Expired
May 21, 1998, 8:40 PM MDT
In force
39 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties; the outline is the Mesonet’s reconstruction

Counties Morgan County, CO, Weld County, CO

The radar

The Cheyenne radar (KCYS), 97 km from the middle of the area, began a volume at 02:00 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
May 21, 8:07 PM MDTHail 0.75Buckingham, 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, 2.0 hours before the alert went out and 101 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 1998-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 600 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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 1998-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -67 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
600 J/kg
Mixed-layer CIN
-98 J/kg
Mixed-layer LCL
2597 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
-67 m²/s²
0-3 km storm-relative helicity
92 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

570 
WUUS1 KDEN 220204 RRA
SVRDEN
COC087-123-220240-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
801 PM MDT THU MAY 21 1998

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
     NORTH CENTRAL MORGAN COUNTY IN NORTHEAST COLORADO
     EAST CENTRAL WELD COUNTY IN NORTHEAST COLORADO

* UNTIL 840 PM MDT

* AT 759 PM MDT WEATHER SERVICE RADAR REPORTED A SEVERE THUNDERSTORM 
9 MILES  SOUTHWEST OF NEW RAYMER...OR ABOUT 23 MILES NORTH OF FORT 
MORGAN... MOVING NORTHEAST AT 15 MILES PER HOUR.

* LOCATIONS IN THE WARNING INCLUDE...NEW RAYMER AND STONEHAM

THE PUBLIC REPORTED 1 INCH DIAMETER HAIL EARLIER WITH THIS STORM. 
THE STORM HAS WEAKENED AT THE MOMENT...BUT IS EXPECTED TO INTENSIFY 
WITHIN THE NEXT 15 MINUTES AS IT APPROACHED THE NEW RAYMER AREA.

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 4060 10408 4048 10390 4061 10364 4079 10380

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 21, 4:16 PM MDT, 3 hours 45 minutes before
COZ043-044-212245-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
416 PM MDT THU MAY 21 1998

...THUNDERSTORM IN
   FAR EAST CENTRAL WELD AND WEST CENTRAL MORGAN COUNTIES OF COLORADO

AT 409 PM MDT THE PUBLIC REPORTED A POSSIBLE TORNADO BETWEEN FORT
MORGAN AND WIGGINS. WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM ABOUT 3 MILES SOUTH OF ORCHARD...OR ABOUT 16 MILES WEST
OF FORT MORGAN...MOVING NORTHEAST AT 30 MILES PER HOUR.

THIS STORM LIES ALONG A BOUNDARY WHICH MAY PRODUCE A BRIEF FUNNEL
CLOUD OR LANDSPOUT.

PERSONS IN OR NEAR GOODRICH...JACKSON RESERVOIR...ORCHARD...WELDONA
AND WIGGINS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND
MOVE TO A PLACE OF SAFETY IF BAD WEATHER APPROACHES.

ENTREKIN
Special weather statement, May 21, 4:16 PM MDT, 3 hours 45 minutes before
COZ043-044-212245-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DENVER CO
416 PM MDT THU MAY 21 1998

...THUNDERSTORM IN
   FAR EAST CENTRAL WELD AND WEST CENTRAL MORGAN COUNTIES OF COLORADO

AT 409 PM MDT THE PUBLIC REPORTED A POSSIBLE TORNADO BETWEEN FORT
MORGAN AND WIGGINS. WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM ABOUT 3 MILES SOUTH OF ORCHARD...OR ABOUT 16 MILES WEST
OF FORT MORGAN...MOVING NORTHEAST AT 30 MILES PER HOUR.

THIS STORM LIES ALONG A BOUNDARY WHICH MAY PRODUCE A BRIEF FUNNEL
CLOUD OR LANDSPOUT.

PERSONS IN OR NEAR GOODRICH...JACKSON RESERVOIR...ORCHARD...WELDONA
AND WIGGINS SHOULD BE ON THE LOOKOUT FOR THREATENING WEATHER AND
MOVE TO A PLACE OF SAFETY IF BAD WEATHER APPROACHES.

ENTREKIN
Local storm report, May 21, 5:30 PM MDT, 2 hours 31 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
530 PM MDT THU MAY 21 1998

...PRELIMINARY STORM REPORT FOR MAY 21 1998...

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0430 PM    18 N NEW RAYMER           CO   0.75 INCH HAIL
05/21/98   WELD

0430 PM    11 NE PAWNEE BUTTES       CO   0.75 INCH HAIL
05/21/98   WELD

0435 PM    15 NE PAWNEE BUTTES       CO   1.00 INCH HAIL
05/21/98   WELD

0445 PM    18 NE PAWNEE BUTTES       CO   0.75 INCH HAIL
05/21/98   WELD

RAY
Local storm report, May 21, 5:30 PM MDT, 2 hours 31 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
530 PM MDT THU MAY 21 1998

...PRELIMINARY STORM REPORT FOR MAY 21 1998...

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0430 PM    18 N NEW RAYMER           CO   0.75 INCH HAIL
05/21/98   WELD

0430 PM    11 NE PAWNEE BUTTES       CO   0.75 INCH HAIL
05/21/98   WELD

0435 PM    15 NE PAWNEE BUTTES       CO   1.00 INCH HAIL
05/21/98   WELD

0445 PM    18 NE PAWNEE BUTTES       CO   0.75 INCH HAIL
05/21/98   WELD

RAY
Local storm report, May 21, 6:40 PM MDT, 1 hour 21 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
0640 PM MDT THU MAY 21 1998

...PRELIMINARY STORM REPORT FOR MAY 21 1998...

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0536 PM    5 E JUELSBURG             CO   1.75 INCH HAIL
05/21/98   SEDGWICK

0530 PM    12 SE SEDGWICK            CO   0.75 INCH HAIL
05/21/98   SEDGWICK

0539 PM    STERLING RES.             C0   1.75 INCH HAIL
05/21/98   LOGAN

0542 PM    5 N WESTPLAINS            CO   1.75 INCH HAIL
05/21/98   LOGAN

0545 PM    10 NW HOLYOKE             CO   1.75 INCH HAIL
05/21/98   PHILLIPS

0557 PM    11 N  HOLYOKE             CO   1.00 INCH HAIL
05/21/98   PHILLIPS

0602 PM    16 S JULESBURG            CO   1.75 INCH HAIL
05/21/98   SEDGWICK

0605 PM    5 SW PEETZ                C0   1.00 INCH HAIL
05/21/98   LOGAN

0607 PM    16 W JULESBURG            CO   2.50 INCH HAIL
05/21/98   SEDGWICK

0615 PM    AMHERST                   CO   2.75 INCH HAIL
05/21/98   PHILLIPS

RAY
Local storm report, May 21, 6:40 PM MDT, 1 hour 21 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
0640 PM MDT THU MAY 21 1998

...PRELIMINARY STORM REPORT FOR MAY 21 1998...

TIME(MDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0536 PM    5 E JUELSBURG             CO   1.75 INCH HAIL
05/21/98   SEDGWICK

0530 PM    12 SE SEDGWICK            CO   0.75 INCH HAIL
05/21/98   SEDGWICK

0539 PM    STERLING RES.             C0   1.75 INCH HAIL
05/21/98   LOGAN

0542 PM    5 N WESTPLAINS            CO   1.75 INCH HAIL
05/21/98   LOGAN

0545 PM    10 NW HOLYOKE             CO   1.75 INCH HAIL
05/21/98   PHILLIPS

0557 PM    11 N  HOLYOKE             CO   1.00 INCH HAIL
05/21/98   PHILLIPS

0602 PM    16 S JULESBURG            CO   1.75 INCH HAIL
05/21/98   SEDGWICK

0605 PM    5 SW PEETZ                C0   1.00 INCH HAIL
05/21/98   LOGAN

0607 PM    16 W JULESBURG            CO   2.50 INCH HAIL
05/21/98   SEDGWICK

0615 PM    AMHERST                   CO   2.75 INCH HAIL
05/21/98   PHILLIPS

RAY

The office that day

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

IssuedProductOfficeCountiesLasted
May 21, 6:13 PM MDTTornado WarningBOUPhillips, Sedgwick22 min
May 21, 6:15 PM MDTSevere Thunderstorm WarningBOULogan45 min
May 21, 7:27 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld33 min
May 21, 8:55 PM MDTSevere Thunderstorm WarningBOULogan, Phillips35 min
May 21, 10:36 PM MDTSevere Thunderstorm WarningBOUAdams, Weld34 min
May 22, 11:56 AM MDTSevere Thunderstorm WarningBOUBoulder, Jefferson34 min
May 22, 12:29 PM MDTSevere Thunderstorm WarningBOUBoulder, Jefferson, Weld46 min
May 22, 12:29 PM MDTSevere Thunderstorm WarningBOUAdams46 min
May 22, 1:00 PM MDTSevere Thunderstorm WarningBOUAdams, Weld30 min
May 22, 1:10 PM MDTSevere Thunderstorm WarningBOUBoulder, Larimer, Weld25 min
May 22, 1:30 PM MDTSevere Thunderstorm WarningBOUAdams, Weld45 min
May 22, 1:35 PM MDTSevere Thunderstorm WarningBOULarimer, Weld40 min
May 22, 1:41 PM MDTSevere Thunderstorm WarningBOUWeld34 min
May 22, 2:06 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe, Denver39 min
May 22, 2:15 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld45 min
May 22, 2:21 PM MDTSevere Thunderstorm WarningBOUWeld24 min
May 22, 2:45 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld45 min
May 22, 2:58 PM MDTSevere Thunderstorm WarningBOUAdams, Arapahoe32 min
May 22, 3:15 PM MDTSevere Thunderstorm WarningBOUMorgan, Weld40 min
May 22, 3:21 PM MDTTornado WarningBOUAdams, Arapahoe24 min
May 22, 3:55 PM MDTSevere Thunderstorm WarningBOUMorgan, Washington35 min
May 22, 4:11 PM MDTSevere Thunderstorm WarningBOUAdams34 min
May 22, 4:30 PM MDTSevere Thunderstorm WarningBOULogan, Morgan, Washington30 min
May 22, 4:40 PM MDTSevere Thunderstorm WarningBOUWashington50 min
May 22, 4:46 PM MDTSevere Thunderstorm WarningBOUAdams, Washington44 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.