Alert archive / Colorado / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 1, NWS Denver/Boulder, CO

May 4, 1998Weld County, Colorado

NWS Denver/Boulder, CO issued this severe thunderstorm warning at May 4, 1998, 2:59 PM MDT for Weld County, Colorado. It was in force for 46 min. No storm report in the archive falls 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.

The facts

Issued
May 4, 1998, 2:59 PM MDT (20:59 UTC)
Expired
May 4, 1998, 3:45 PM MDT
In force
46 min
Issued by
NWS Denver/Boulder, CO
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Weld County, CO

The radar

The Cheyenne radar (KCYS), 58 km from the middle of the area, began a volume at 21:02 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.

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 9.0 hours before the alert went out and 158 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 12:00Z on 1998-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 1998-05-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 109 square meters per square second.1939587897117Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3187 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
109 m²/s²
0-3 km storm-relative helicity
94 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.

642 
WUUS1 KDEN 042101 RRA
SVRDEN
COC123-042145-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DENVER CO
259 PM MDT MON MAY 4 1998

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

   * SEVERE THUNDERSTORM WARNING FOR...
     WEST CENTRAL WELD COUNTY IN NORTHEAST COLORADO

   * UNTIL 345 PM MDT

   * AT 253 PM MDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
     SEVERE THUNDERSTORM 8 MILES WEST OF NUNN...OR ABOUT 11 MILES
     NORTHEAST OF FORT COLLINS...MOVING EAST AT 20 MILES PER HOUR.

   * LOCATIONS IN THE WARNING INCLUDE NORTHEASTERN GREELEY...AULT...
     EATON...LUCERNE...NUNN...PIERCE AND PURCELL

HAIL UP TO 3/4 INCHES IN DIAMETER HAS BEEN REPORTED WITH THIS STORM
12 MILES NORTHEAST OF FORT COLLINS. IF YOU ARE IN THE PATH OF THE 
STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A SUBSTANTIAL SHELTER.

LAT...LON 4070 10493 4062 10494 4043 10470 4071 10454
GARD...WSFO DENVER

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 4, 11:10 AM MDT, 3 hours 49 minutes before
COZ030-032>050-050600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
1110 AM MDT MON MAY 4 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

...SPOTTER ACTIVATION WILL NOT BE NECESSARY TODAY OR TONIGHT...

SYNOPSIS:  A COLD FRONT MOVING OUT OF WYOMING AND NEBRASKA WILL
BRING GUSTY NORTHERLY WINDS ACROSS THE PLAINS THIS AFTERNOON.  WIND
SPEEDS OF 15 TO 25 MPH WITH SOME GUSTS TO 35 MPH MAY PRODUCE SOME
AREAS OF BLOWING DUST.  COOLER AIR MOVING INTO THE STATE BEHIND THE
COLD FRONT WILL HELP TO STABILIZE THE AIRMASS AND INHIBIT ANY
AFTERNOON SHOWER ACTIVITY ON THE PLAINS.  SOME CLOUDS AND SHOWERS
MAY STILL DEVELOP OVER THE MOUNTAINS AND FOOTHILLS DURING THE
AFTERNOON...BUT THE AIRMASS OVER THE CENTRAL PART OF THE STATE IS
QUITE DRY...SO ONLY ISOLATED SHOWERS ARE EXPECTED.  NONE OF THE
STORMS WHICH DEVELOP WILL PRODUCE ANY SIGNIFICANT WEATHER.

OUTLOOK FOR TUESDAY...COOL AND MOIST AIR WILL REMAIN OVER NORTHEAST
COLORADO TOMORROW WITH SCATTERED RAIN SHOWERS IN THE MORNING AND A
FEW THUNDERSTORMS POSSIBLE IN THE AFTERNOON.

DANKERS
Special weather statement, May 4, 11:10 AM MDT, 3 hours 49 minutes before
COZ030-032>050-050600-

SIGNIFICANT WEATHER OUTLOOK FOR NORTHEAST AND NORTH CENTRAL COLORADO
NATIONAL WEATHER SERVICE DENVER CO
1110 AM MDT MON MAY 4 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

...SPOTTER ACTIVATION WILL NOT BE NECESSARY TODAY OR TONIGHT...

SYNOPSIS:  A COLD FRONT MOVING OUT OF WYOMING AND NEBRASKA WILL
BRING GUSTY NORTHERLY WINDS ACROSS THE PLAINS THIS AFTERNOON.  WIND
SPEEDS OF 15 TO 25 MPH WITH SOME GUSTS TO 35 MPH MAY PRODUCE SOME
AREAS OF BLOWING DUST.  COOLER AIR MOVING INTO THE STATE BEHIND THE
COLD FRONT WILL HELP TO STABILIZE THE AIRMASS AND INHIBIT ANY
AFTERNOON SHOWER ACTIVITY ON THE PLAINS.  SOME CLOUDS AND SHOWERS
MAY STILL DEVELOP OVER THE MOUNTAINS AND FOOTHILLS DURING THE
AFTERNOON...BUT THE AIRMASS OVER THE CENTRAL PART OF THE STATE IS
QUITE DRY...SO ONLY ISOLATED SHOWERS ARE EXPECTED.  NONE OF THE
STORMS WHICH DEVELOP WILL PRODUCE ANY SIGNIFICANT WEATHER.

OUTLOOK FOR TUESDAY...COOL AND MOIST AIR WILL REMAIN OVER NORTHEAST
COLORADO TOMORROW WITH SCATTERED RAIN SHOWERS IN THE MORNING AND A
FEW THUNDERSTORMS POSSIBLE IN THE AFTERNOON.

DANKERS

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.