Alert archive / North Dakota / Severe Thunderstorm Watches in 1997

Severe Thunderstorm Watch 677

August 8, 19977 counties in Montana; 12 counties in North Dakota

The Storm Prediction Center issued this severe thunderstorm watch at Aug 8, 1997, 1:30 PM MDT for 7 counties in Montana; 12 counties in North Dakota. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued: Aug 8, 1997, 1:30 PM MDT (19:30 UTC)
Expired: Aug 8, 1997, 8:00 PM MDT
In force: 7 hr
Issued by: the Storm Prediction Center

Counties Daniels County, MT, Dawson County, MT, McCone County, MT, Richland County, MT, Roosevelt County, MT, Sheridan County, MT, Valley County, MT, Billings County, ND, Burke County, ND, Divide County, ND, Dunn County, ND, McKenzie County, ND, McLean County, ND, Mercer County, ND, Mountrail County, ND, Oliver County, ND, Renville County, ND, Ward County, ND, Williams County, ND

The radar

The Glasgow radar (KGGW), 156 km from the middle of the area, began a volume at 19:30 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.

Warnings issued inside it

1 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Aug 8, 2:10 PM MDT	Severe Thunderstorm Warning	GGW	Daniels	65 min

The nearest sounding before it

Glasgow Intl Airport, MT (KGGW), launched 12:00Z, 7.5 hours before the alert went out and 155 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: 5 J/kg
Mixed-layer CIN: -203 J/kg
Mixed-layer LCL: 1822 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 102 m²/s²
0-3 km storm-relative helicity: 132 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.

246 
WWUS9 KMKC 081913
SEL7  
MKC WW 081913
MTZ000-NDZ000-090200-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 678
STORM PREDICTION CENTER NORMAN OK
113 PM MDT FRI AUG 8 1997

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   NORTHEAST MONTANA                            
   WESTERN NORTH DAKOTA                       

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 130 PM UNTIL 800
PM MDT.

HAIL TO 1 3/4 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 85
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 70 STATUTE MILES
NORTH AND SOUTH OF A LINE FROM 20 MILES SOUTHWEST OF GLASGOW
MONTANA TO 25 MILES SOUTHEAST OF MINOT NORTH DAKOTA.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.


DISCUSSION...POTENTIAL FOR DAMAGING WINDS AND HAIL THIS AFTERNOON
AND EVENING ACROSS WATCH AREA...WHERE VERTICAL MOTION ASSOCIATED
WITH EXIT REGION OF 65 KT 500 MB SPEED MAX WILL ACT WITH DAYTIME
HEATING TO FURTHER DESTABILIZE AIR MASS AHEAD OF COLD FRONT...WHERE
SURFACE TEMPERATURES IN THE MID 80S AND DEWPOINTS IN THE MID 50S
ARE YIELDING CAPE ARND 2000 J/KG.    


AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1 3/4 INCHES.  EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 75
KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400.  MEAN STORM
MOTION VECTOR 27040.


...CORFIDI

490,1065 490,1005 465,1005 470,1065

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 8, 1:30 PM MDT	Severe Thunderstorm Watch	SPC	Daniels, Dawson, McCone, Richland, Roosevelt, Sheridan and 1 more	7 hr

Nearby

Severe Thunderstorm Watches in North Dakota, 1997 Severe Thunderstorm Watches in Montana, 1997 Every severe thunderstorm watch in 1997

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.