Alert archive / North Dakota / Tornado Warnings in 1999

Tornado Warning 15, NWS Bismarck, ND

June 8, 1999Sioux County, North Dakota

NWS Bismarck, ND issued this tornado warning at Jun 8, 1999, 8:09 PM CDT for Sioux County, North Dakota. 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 counties it named.

The facts

Issued: Jun 8, 1999, 8:09 PM CDT (01:09 UTC)
Expired: Jun 8, 1999, 8:55 PM CDT
In force: 46 min
Issued by: NWS Bismarck, ND
Area: Whole counties

County Sioux County, ND

The radar

The Bismarck radar (KBIS), 76 km from the middle of the area, began a volume at 01:28 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

Bismarck Municip, ND (KBIS), launched 00:00Z, 1.2 hours before the alert went out and 78 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: 3431 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 878 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 115 m²/s²
0-3 km storm-relative helicity: 130 m²/s²
Significant tornado parameter: 1.8
Supercell composite: 11.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KBIS 090112
TORBIS
NDC085-090155-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE BISMARCK ND
809 PM CDT (709 PM MDT) TUE JUN 8 1999

THE NATIONAL WEATHER SERVICE IN BISMARCK HAS ISSUED A

* TORNADO WARNING FOR...
  SIOUX COUNTY IN SOUTH CENTRAL NORTH DAKOTA

* UNTIL 755 PM MDT (855 PM CDT)

* AT 805 PM CDT...SPOTTERS INDICATED A TORNADO 6 MILES SOUTH OF
  MCINTOSH SOUTH DAKOTA...MOVING NORTHEAST AT 20 MPH...TOWARD SIOUX
  COUNTY NO.RTH DAKOTA.

* THE TORNADO IS EXPECTED TO...
  CROSS INTO SIOUX COUNTY NEAR HIGHWAY 31 AND REMAIN IN RURAL
  AREAS.

GO TO THE BASEMENT OR A SMALL INTERIOR ROOM ON THE LOWEST FLOOR!

JP MARTIN

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 Bismarck, ND wrote its last area forecast discussion before this tornado warning went out at Jun 8, 3:12 PM CDT, 4 hours 57 minutes earlier.

Area forecast discussion, Jun 8, 3:12 PM CDT, 4 hours 57 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
312 PM CDT TUE JUN 8 1999

ACTIVE EVENING AGAIN AS TSRA ARE BEGIN TO FIRE ALONG/JUST AHEAD OF
CDFNT ALONG MT BDR AND AHEAD OF APPROACHING UPR LVL TROF OVR THE NRN
ROCKIES. VERY UNSTABLE AMS OVR THE CWA AND UVV'S INCREASING ALONG
STRONG MID LVL JET STREAK. XPCT TSRA TO INCREASE BCMG SVR ALONG THE
BNDRY THS AFTN IN THE WEST AND NORTH. SYS WL SLOWLY MOV EAST TNGT
WITH THE THREAT OF MCS DVLPG WHICH IS MAINLY A HAIL AND HEAVY RAIN
PRODUCER.

-SHRA WL CONT INTO WED BUT XPCT ACTIVITY TO END IN THE AFTN AS SYS
EJECTS INTO SRN CANADA. UPR PATTERN BECMS MORE ZONAL WITH CHANNELED
PVA LATE IN THE PD AND BRING A MORE SETTLED PATTERN TO THE ,CWA THRU
THE WEEKEND.

THE EXTENDED SHWS SAME PATTERN WITH MAINLY DRY CONDITIONS INTO THE
WEEKEND.

.BIS...NONE.
RGT

The office that day

Everything else NWS Bismarck, ND issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 8, 7:18 PM CDT	Tornado Warning	BIS	Renville, Ward	42 min
Jun 8, 11:01 PM CDT	Severe Thunderstorm Warning	BIS	Stutsman	59 min
Jun 8, 11:39 PM CDT	Severe Thunderstorm Warning	BIS	Emmons	66 min
Jun 9, 12:14 AM CDT	Severe Thunderstorm Warning	BIS	Kidder	61 min
Jun 9, 1:21 AM CDT	Severe Thunderstorm Warning	BIS	Stutsman	54 min
Jun 9, 2:00 AM CDT	Severe Thunderstorm Warning	BIS	Foster	60 min
Jun 9, 3:20 AM CDT	Severe Thunderstorm Warning	BIS	Sioux	30 min

Nearby

Tornado Warnings in North Dakota, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.