Alert archive / Colorado / Tornado Warnings in 1999

Tornado Warning 30, NWS Denver/Boulder, CO

June 26, 1999Logan County, Phillips County, Sedgwick County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Jun 26, 1999, 9:14 PM MDT for Logan County, Phillips County, Sedgwick County, Colorado. It was in force for 41 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: Jun 26, 1999, 9:14 PM MDT (03:14 UTC)
Expired: Jun 26, 1999, 9:55 PM MDT
In force: 41 min
Issued by: NWS Denver/Boulder, CO
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Logan County, CO, Phillips County, CO, Sedgwick County, CO

The radar

The Cheyenne radar (KCYS), 178 km from the middle of the area, began a volume at 03:14 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 26, 9:45 PM MDT	Hail 0.75	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 26, 6:00 PM MDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Denver, CO (KDNR), launched 00:00Z, 3.2 hours before the alert went out and 108 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 828 J/kg
Mixed-layer CIN: -63 J/kg
Mixed-layer LCL: 2518 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 31 m²/s²
0-3 km storm-relative helicity: 171 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 3.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDEN 270319 RRA
TORDEN
COC075-095-115-270355-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DENVER CO
914 PM MDT SAT JUN 26 1999

THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN LOGAN COUNTY IN NORTHEAST COLORADO
  PHILLIPS COUNTY IN NORTHEAST COLORADO
  THIS INCLUDES THE CITY OF HOLYOKE
  WESTERN SEDGWICK COUNTY IN NORTHEAST COLORADO

* UNTIL 955 PM MDT

* AT 914 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  THUNDERSTORM WITH A POSSIBLE TORNADO 4 MILES WEST OF MARKS BUTTE...
  OR ABOUT 20 MILES SOUTHWEST OF JULESBURG...MOVING SOUTHEAST AT 30
  MPH.

LOCATIONS IN THE WARNING INCLUDE...BUT ARE NOT LIMITED TO...WAGES...
TWIN BUTTES...ST PETERSBURG...SIXTEEN-MILE CORNER...SEDGWICK...
JULESBURG...PROCTOR...PAOLI...OVID...MARKS BUTTE...ILIFF... 
HOLYOKE...HIGHLAND CENTER...HAXTUN... FLEMING...FAIRFIELD...CROOK 
AND AMHERST

THIS WARNING REPLACES THE TORNADO WARNING ISSUED AT 844PM.  

THIS IS AN EXTREMELY DANGEROUS AND POTENTIALLY LIFE THREATENING
SITUATION. IF YOU ARE IN THE PATH OF THIS LARGE AND DESTRUCTIVE 
TORNADIC STORM...TAKE COVER IMMEDIATELY.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

LAT...LON 4095 10302 4077 10309 4047 10296 4046 10207
          4099 10231
RTG

What forecasters said that day

The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Denver/Boulder, CO wrote its last area forecast discussion before this tornado warning went out at Jun 26, 3:19 PM MDT, 5 hours 55 minutes earlier.

Area forecast discussion, Jun 26, 3:19 PM MDT, 5 hours 55 minutes before

NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER COLORADO
230 PM MDT SAT JUN 26 1999

SHORT TERM:  THE THREAT OF SVR TSTMS OVR THE NERN PLAINS THIS
EVENING STILL LOOKS TO BE THE MAIN CONCERN.  LOW LVL MSTR HAS BEEN
INCRG OVR THE NERN PLAINS AS PRVSLY FCST.  THIS IN COMBINATION WITH
SOME UPPER LVL DYNAMICS MOVING IN FM THE W MAY GET THINGS GOING ON
OR AFT 00Z TDA.  CAPE VALUES APPEAR TO BE IN THE 2000-3000 J/KG
RANGE.  BEST CHC WUD APPEAR TO BE IN THE 00-06Z TIME FRAME.  PW
VALUES NR THE KS/NEBRASKA BORDER ARND 1.2 INCHES THIS EVENING WITH
ETA DVLPG MCS COMPLEX OVRNGT TNGT...SO HEAVY RAIN WL BE ANOTHER
PROBLEM.  SHEAR PROFILES SHOULD SUPPORT HAIL...PSBL TORNADOS...BUT
MOST OF THIS SHUD BE EAST OF THE I-25 CORRIDOR.  WITH BNDRY LEVEL RH
OVR MUCH OF THE NERN PLAINS TNGT WL ALSO MENTION POSSIBILITY OF
FOG.  SFC AND H7 THETA-E RIDGE WL RMN OVR NERN CO ON SUNDAY...BUT
DYNAMICS MAY NOT BE AS MUCH OF A FACTOR IN THE AFTN.  FCST SOUNDINGS
AGN SHOW CAPE VALUES IN THE 1500-2000 J/KG.  ZONAL FLOW TO CONTINUE
MON...BUT AVN INDICATES DRIER AT THE LOW LVLS.  SO WL LOWER TSTM
POTENTIAL AT THAT TIME.  IN THE EXTENDED...W-NWLY FLOW WL CONTINUE
WITH  UPPER TROF CROSSING THE REGION BY MID-WEEK.  THEREFORE WL
CONTINUE WITH A CHC OF STORMS EACH DAY.  COOPER

.DEN...NONE.

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 26, 7:20 PM MDT	Severe Thunderstorm Warning	BOU	Elbert	40 min
Jun 26, 7:33 PM MDT	Severe Thunderstorm Warning	BOU	Lincoln	27 min
Jun 26, 7:34 PM MDT	Tornado Warning	BOU	Logan	41 min
Jun 26, 8:15 PM MDT	Tornado Warning	BOU	Logan	30 min
Jun 26, 8:44 PM MDT	Tornado Warning	BOU	Logan, Sedgwick	46 min
Jun 26, 9:55 PM MDT	Tornado Warning	BOU	Logan, Phillips, Sedgwick	35 min
Jun 26, 10:30 PM MDT	Tornado Warning	BOU	Logan, Phillips	20 min

Nearby

Tornado Warnings in Colorado, 1999 Every tornado warning in 1999 Tornadoes in 1999

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.