Alert archive / Wyoming / Tornado Warnings in 1996

Tornado Warning 25, NWS Cheyenne, WY

July 31, 1996Niobrara County, Wyoming

NWS Cheyenne, WY issued this tornado warning at Jul 31, 1996, 2:04 PM MDT for Niobrara County, Wyoming. It was in force for 56 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 31, 1996, 2:04 PM MDT (20:04 UTC)
Expired
Jul 31, 1996, 3:00 PM MDT
In force
56 min
Issued by
NWS Cheyenne, WY
Area
Whole counties

County Niobrara County, WY

The radar

The Rapid City radar (KUDX), 178 km from the middle of the area, began a volume at 20:07 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

Rapid City, SD (KUNR), launched 12:00Z, 8.1 hours before the alert went out and 171 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, Rapid City, SD at 12:00Z on 1996-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 30 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Rapid City, SD at 12:00Z on 1996-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 square meters per square second.19395878Sfc1 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
30 J/kg
Mixed-layer CIN
-101 J/kg
Mixed-layer LCL
669 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
37 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.

000 
TTAA00 KCYS 312007
TORCYS
WYC027-312100-
 
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE CHEYENNE WY
204 PM MDT WED JUL 31 1996
 
THE NATIONAL WEATHER SERVICE IN CHEYENNE HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL  300 PM MDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN EAST CENTRAL WYOMING
 
   ...NIOBRARA COUNTY
 
AT 2 PM MDT...DOPPLER RADAR INDICATED SEVERAL SEVERE THUNDERSTORMS OVER
NORTHERN NIOBRARA. ONE OVER NORTHWEST AND ANOTHER OVER NORTHEAST
NIOBRARA COUNTIES.  SEVERAL FUNNEL CLOUDS WERE REPORTED FROM THE
NORTHEAST NIOBRARA STORM.  A THIRD THUNDERSTORM INDICATED SEVERE
OVER WEST CENTRAL NIOBRARA COUNTY 11 WEST SOUTHWEST OF LANCE CREEK.
ROTATION WAS DETECTED IN THE STORMS.  THE STORMS WERE MOVING SOUTHEAST
AT 25 MILES AN HOUR.
 
DOPPLER RADAR DETECTED STRONG ROTATION IN THESE STORM.  ANY ONE OF THE
STORMS HAS THE POTENTIAL TO PRODUCE A TORNADO AT ANY MOMENT!
 
GO TO SAFE SHELTER WHEN THREATENING WEATHER APPROACHE"S.
 
WCJIN-WYNE
PAL

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.

In the hours before

Special weather statement, Jul 31, 9:19 AM MDT, 4 hours 45 minutes before
WYZ059>070-NEZ001>003-019>021-054-055-312300-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHEYENNE WY
920 AM MDT WED JUL 31 1996

THE SEVERE WEATHER POTENTIAL IN THE COUNTY WARNING AREA OF THE CHEYENNE
NATIONAL WEATHER SERVICE OFFICE IS MEDIUM THIS AFTERNOON AND
EVENING...MAINLY IN THE NEBRASKA PANHANDLE.

SPOTTER ACTIVATION MAY BE NECESSARY FOR THE NEBRASKA PANHANDLE.

DISCUSSION...THE AIRMASS OVER SOUTHEAST WYOMING IS EXPECTED TO DRY OUT
SOME DURING THE DAY AS A SURFACE LOWS PRESSURE TROUGH MOVES E OF THE
STATE WITH DOWNSLOPE WESTERLY FLOW DEVELOPING AT THE SURFACE DURING THE
AFTERNOON.  THE AIRMASS OVER THE NEBRASKA WILL REMAIN MOIST TODAY AS
SOUTHEAST UPSLOPE WINDS KEEP DEW POINTS IN THE UPPER 50S.  BETTER
INSTABILITIES AND CONVECTIVE POTENTIAL ENERGY ARE PROGED OVER THE
NEBRASKA PANHANDLE THIS AFTERNOON AND EVENING.  THE WIND PROFILE WILL
ALSO REMAIN FAVORABLE FOR THE FORMATION OF SOME SUPER CELLS OVER THE
NEBRASKA PANHANDLE.

THIS OUTLOOK IS FOR THE FOLLOWING COUNTIES IN SOUTHEAST WYOMING AND
THE NEBRASKA PANHANDLE:

WY...ALBANY   CARBON   CONVERSE   GOSHEN   LARAMIE   NIOBRARA   PLATTE
NE...BANNER   BOX BUTTE   CHEYENNE   DAWES   KIMBALL   MORRILL   SIOUX
     STCOTTS BLUFF

WCJIN-WYSE-WYNE
PAL
Special weather statement, Jul 31, 12:17 PM MDT, 1 hour 47 minutes before
WYZ059-064-066-067-069-070-311900-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHEYENNE WY
1210 PM MDT WED JUL 31 1996

AT 1205 PM MDT...DOPPLER RADAR INDICATED THUNDERSTORMS DEVELOPING
OVER EAST CENTRAL AND SOUTHEAST WYOMING.  ONE STORM THAT DEVELOPED
OVER EASTERN NATRONA COUNTY WAS MOVING INTO THE WEST END OF CONVERSE
COUNTY AND WAS LOCATED 15 MILES WEST OF GLENROCK OR 35 MILES WEST
NORTHWEST OF DOUGLAS.  A SECOND STRONG THUNDERSTORM WAS LOCATED
25 MILES NORTHWEST OF WHEATLAND IN PLATTE COUNTY.  A THIRD STORM
WAS LOCATED OVER NORTH CHEYENNE.  THIS STORM WAS PRODUCING SMALL
HAIL...1/2 INCH IN DIAMETER.  STORMS WERE MOVING TO THE SOUTHEAST AT
20 MILES AN HOUR.

SMALL HAIL...XBRIEF HEAVY RAIN...DANGEROUS LIGHTNING AND GUSTY WINDS
TO 45 MILES AN HOUR CAN BE EXPECTED WITH THESE STORMS UNTIL 115 PM.

WCJIN-WYSE-WYNE
PAL

The office that day

Everything else NWS Cheyenne, WY issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 30, 6:44 PM MDTSevere Thunderstorm WarningCYSGoshen31 min
Jul 30, 7:04 PM MDTSevere Thunderstorm WarningCYSLaramie26 min
Jul 31, 1:43 PM MDTSevere Thunderstorm WarningCYSConverse62 min
Jul 31, 2:00 PM MDTSevere Thunderstorm WarningCYSGoshen, Platte60 min
Jul 31, 2:28 PM MDTTornado WarningCYSConverse32 min
Jul 31, 2:40 PM MDTTornado WarningCYSGoshen50 min
Jul 31, 2:52 PM MDTTornado WarningCYSLaramie38 min
Jul 31, 3:07 PM MDTSevere Thunderstorm WarningCYSGoshen, Niobrara68 min
Jul 31, 3:28 PM MDTSevere Thunderstorm WarningCYSGoshen47 min
Jul 31, 3:35 PM MDTSevere Thunderstorm WarningCYSLaramie40 min

Nearby

Tornado Warnings in Wyoming, 1996Every tornado warning in 1996Tornadoes in 1996

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.