Slope County Natural Disasters and Weather Extremes
The chance of earthquake damage in Slope County is about the same as North Dakota average and is much lower than the national average. The risk of tornado damage in Slope County is much lower than North Dakota average and is much lower than the national average.
Earthquake Index, #23
| Slope County | 0.00 |
| North Dakota | 0.00 |
| U.S. | 1.81 |
The earthquake index value is calculated based on historical earthquake events data using USA.com algorithms. It is an indicator of the earthquake level in a region. A higher earthquake index value means a higher chance of an earthquake.
Volcano Index, #1
| Slope County | 0.0000 |
| North Dakota | 0.0000 |
| U.S. | 0.0023 |
The volcano index value is calculated based on the currently known volcanoes using USA.com algorithms. It is an indicator of the possibility of a region being affected by a possible volcano eruption. A higher volcano index value means a higher chance of being affected.
Tornado Index, #44
| Slope County | 0.00 |
| North Dakota | 81.79 |
| U.S. | 136.45 |
The tornado index value is calculated based on historical tornado events data using USA.com algorithms. It is an indicator of the tornado level in a region. A higher tornado index value means a higher chance of tornado events.
Other Weather Extremes Events
A total of 3,524 other weather extremes events within 50 miles of Slope County were recorded from 1950 to 2010. The following is a break down of these events:
| Type | Count | Type | Count | Type | Count | Type | Count | Type | Count |
| Avalanche: | 0 | Blizzard: | 70 | Cold: | 28 | Dense Fog: | 1 | Drought: | 13 |
| Dust Storm: | 0 | Flood: | 90 | Hail: | 1,821 | Heat: | 5 | Heavy Snow: | 54 |
| High Surf: | 0 | Hurricane: | 0 | Ice Storm: | 4 | Landslide: | 0 | Strong Wind: | 107 |
| Thunderstorm Winds: | 1,126 | Tropical Storm: | 0 | Wildfire: | 15 | Winter Storm: | 58 | Winter Weather: | 18 |
| Other: | 114 | ||||||||
Volcanos Nearby
No volcano is found in or near Slope County.
Historical Earthquake Events
No historical earthquake events that had recorded magnitudes of 3.5 or above found in or near Slope County.
No historical earthquake events found in or near Slope County.
Historical Tornado Events
A total of 10 historical tornado events that had recorded magnitude of 2 or above found in or near Slope County.
| Distance (miles) | Date | Magnitude | Start Lat/Log | End Lat/Log | Length | Width | Fatalities | Injuries | Property Damage | Crop Damage | Affected County |
| 22.2 | 1977-06-14 | 2 | 46°15'N / 103°53'W | 46°12'N / 103°43'W | 8.20 Miles | 33 Yards | 0 | 1 | 250K | 0 | Bowman |
| 23.4 | 1957-04-22 | 2 | 46°44'N / 103°12'W | 0.50 Mile | 800 Yards | 0 | 0 | 3K | 0 | Stark | |
| 29.8 | 2001-07-25 | 2 | 46°46'N / 103°53'W | 46°46'N / 103°53'W | 5.00 Miles | 60 Yards | 0 | 0 | 0 | 0 | Golden Valley |
| Brief Description: The tornado remained in open country but hit a farmstead causing major damage. Windows blown out. Singles and siding ripped off. | |||||||||||
| 35.1 | 1952-06-10 | 2 | 46°47'N / 103°01'W | 46°47'N / 102°48'W | 10.10 Miles | 33 Yards | 0 | 0 | 25K | 0 | Stark |
| 37.5 | 1976-06-04 | 2 | 46°55'N / 103°12'W | 47°00'N / 103°12'W | 5.70 Miles | 33 Yards | 0 | 0 | 25K | 0 | Stark |
| 37.8 | 1999-06-20 | 2 | 46°32'N / 104°11'W | 46°38'N / 104°17'W | 5.00 Miles | 300 Yards | 0 | 0 | 0 | 0 | Fallon |
| Brief Description: A large tornado which touched down near Ollie Road, about 3 miles east of Montana Highway 7. The tornado travelled north to County Road 616 then northwest over Beaver Creek before lifting at the Fallon/Wibaux County border. The tornado destroyed a well built cattle shed, lifted up, twisted and moved a large irrigation pipe about 100 yards and sucked the water out of a section of Beaver Creek. | |||||||||||
| 39.7 | 2001-07-25 | 2 | 46°33'N / 104°17'W | 46°33'N / 104°17'W | 2.00 Miles | 200 Yards | 0 | 0 | 0 | 0 | Fallon |
| Brief Description: NWS Post-Storm Damage Assessment Team determined F2 tornado 200 yards wide with a path length of 2 miles. It was on the ground for 15 minutes over open range west of State Highway 7. | |||||||||||
| 42.3 | 2009-07-08 | 3 | 46°51'N / 102°49'W | 46°51'N / 102°46'W | 2.00 Miles | 350 Yards | 0 | 2 | 20.0M | 0K | Stark |
| Brief Description: EVENT NARRATIVE: Meteorologists from the National Weather Service conducted a storm damage survey in and around Dickinson on Thursday, July 9th, 2009. Meteorologists walked through the area and spoke with numerous people affected, many of whom were eye witnesses to the event. This tornado passed through the city of Dickinson on the far south side, mainly just south of the Heart River. No witnesses spoken to actually saw the tornado. From their eye witness accounts, and from video obtained by the Dickinson Police Department, it is likely that this was a rain-wrapped tornado, and very difficult if not impossible to see. The tornado occurred before sunset, yet it was described as being as dark as night during the event. The conclusion of the damage survey was that this tornado touched down around a mile or so outside the city limits, on the southwest side, and moved east-northeast, passing through the far southern part of the city. It lifted back into the parent thunderstorm on the extreme southeast side of Dickinson near the city limit. This occurred in the window between 815 PM MDT and 830 PM MDT. Over 450 structures were damaged, of which nearly 100 were declared completely destroyed or beyond repair. Numerous vehicles were damaged or destroyed, some were on their roofs. Power lines were snapped, knocking out power to most of Dickinson, and tree damage was extensive. Two minor injuries were reported, with no deaths. The injuries were to a 23 year old male and a 42 year old male. Both occurred in homes. The worst damage surveyed was between the Heart River and roughly 8th Street Southwest and 8th Street Southeast in southern Dickinson. Of that damage, the absolute worst corresponded to middle EF3 on the Enhanced Fujita Tornado Scale. From that it was determined that peak wind speeds in the tornado were on the order of 150 mph. Other parts of Dickinson and the surrounding area sustained wind damage likely associated with the rear flank downdraft of the storm. EPISODE NARRATIVE: In the mid afternoon hours of Wednesday, July 8th, Tornado Watch 563 was issued for all of western and parts of central North Dakota, due to the expected widespread and dangerous development and rapid intensification of thunderstorms near a surface trough along the western North Dakota border. Destabilization along the surface trough, coupled with the approach of a strong upper level trough and an intensifying late afternoon/early evening low level jet, all contributed to the watch issuance. Later Wednesday evening, Severe Thunderstorm Watch 565 was issued for much of central North Dakota to replace the expiring Tornado Watch, and specifically to account for a developing bow echo which was expected to push east across the watch area into the early morning hours of Thursday, July 9th. The end result was a large severe weather outbreak experienced across much of west and central North Dakota, lasting from the late afternoon hours of the 8th, into the early morning hours of the 9th. Multiple severe thunderstorm and tornado warnings were issued. Numerous reports of large hail and severe thunderstorm wind gusts were received throughout this event. Several tornadoes occurred, including an EF3 within city limits on the south side of Dickinson. That tornado alone resulted in over twenty million dollars in damage. | |||||||||||
| 45.6 | 1952-07-19 | 3 | 47°00'N / 104°03'W | 47°01'N / 103°53'W | 7.30 Miles | 33 Yards | 0 | 0 | 3K | 0 | Golden Valley |
| 49.4 | 1952-07-19 | 3 | 46°58'N / 104°15'W | 47°00'N / 104°03'W | 9.10 Miles | 33 Yards | 1 | 2 | 250K | 0 | Wibaux |
* The information on this page is based on the global volcano database, the U.S. earthquake database of 1638-1985, and the U.S. Tornado and Weather Extremes database of 1950-2010.