Thunderstorms developed during the morning into the mid-day hours over central and eastern North Dakota to the north of a surface and upper level low pressure system. One thunderstorm near Bordoulac produced a landspout tornado which was slow moving and lasted about 15 minutes.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS BIS wrote it up.
Thunderstorms developed during the morning into the mid-day hours over central and eastern North Dakota to the north of a surface and upper level low pressure system. One thunderstorm near Bordoulac produced a landspout tornado which was slow moving and lasted about 15 minutes. No damage occurred with this tornado and so it was rated EF0.
The local office's own words before the first event, 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 the first event at May 30, 8:47 AM CST, 2 hours 28 minutes earlier.
Area Forecast Discussion National Weather Service Bismarck ND 947 AM CDT Wed May 30 2018 .UPDATE... Issued at 933 AM CDT Wed May 30 2018 Latest surface and upper air analysis shows surface and upper level low situated over north central SD. Scattered showers and isolated thunderstorms over the James River Valley into the Turtle Mountains , and from around Minot down toward Hebron and Mott. Should be enough dry air to inhibit convection west of this line, but from here eastward, scattered showers and thunderstorms are possible through the afternoon. Updated pops based on latest radar and short term model guidance. UPDATE Issued at 631 AM CDT Wed May 30 2018 GOESEast IR imagery depicts warming clouds tops associated with the band of rain showers and thunderstorms from Hettinger through Kenmare as of 1137 UTC. This weakening trend should continue through the morning. Radar estimates 3-4 inches of rain has fallen from near Berthold to near Plaza and Parshall from very slow moving storms overnight. However, MRMS FLASH-CREST Unit Stream Flow data suggests that any flooding would likely be localized to low lying areas. && .SHORT TERM...(Today and tonight) Issued at 250 AM CDT Wed May 30 2018 Convective potential today highlights the short term forecast. As of 0830 UTC, scattered showers and thunderstorms continue across western North Dakota within an axis of higher precipitable water north of the upper level low across western South Dakota. Storm motions are slow with weak deep layer flow. Thus, locally heavy rainfall is possible. However, flooding is not a significant concern given antecedent soil conditions. Patchy fog will also continue this morning across the west and north central with weak flow and saturated boundary layer conditions. As the upper level low propagates into eastern North and South Dakota by this afternoon, scattered thunderstorm development is expected across central North Dakota with daytime heating. Slow storms motions are expected with weak deep layer flow, with locally heavy rainfall possible. Again, flooding is not a concern other than for highly localized areas such as underpasses in urban areas. Given weak shear, severe weather is not expected. Did raise highs over the 00 UTC consensus into the lower 80s across the west and far south central where sunshine will be greater with enhanced mixing via northwest surface winds. .LONG TERM...(Thursday through Tuesday) Issued at 250 AM CDT Wed May 30 2018 Severe convective potential Thursday, and especially Friday, highlight the extended forecast. The 00 UTC global consensus continues to support two days of possible severe weather Thursday, and to a greater extent and possible magnitude on Friday. Northwest North Dakota remains in a Slight Risk in the SPC convective outlook for Thursday, with a Marginal Risk southwest and through much of the US Highway 83 corridor. The most likely scenario is for potential convective initiation across northeast Montana into northwest North Dakota along a surface inverted trough late Thursday afternoon or early evening with multiple impulses aloft propagating along the upper level ridge. Moderate instability and strong deep layer shear supports the potential for organized severe convection. Given shear orientation somewhat parallel to the surface boundary, storms may quickly cluster, with possible MCS formation along the international border through the late evening and overnight sustained by a strengthening low level jet. Scattered elevated convection may develop across the remainder of western and central North Dakota through the night with the low level jet, continued moisture transport, Elevated Mixed Layer (EML) arrival and impulses in southwest flow aloft. What could be the most significant severe weather event of the season thus far is possible across western and central North Dakota on Friday. This has been consistently shown by the global suite and CIPs analogs. SPC has placed most of western and central North Dakota in a Slight Risk in their Day 3 outlook. With continued moisture transport, moderate to strong instability is forecast to potentially build especially across central North Dakota within the warm sector of the surface low. Deep layer shear is forecast to be sufficient for organized convection, with the highest shear however potentially lagging the cold/occluding front. Strong forcing with the arrival of the significant shortwave and mid level jet is expected late Friday afternoon through Friday night, coupled with low level forcing with the occluding frontal boundaries. All threats are possible as storm mode may range from initial supercells to upscale growth into linear segments. Certainly questions of capping and cloud cover impacts from overnight convection remain, and likely will into Friday. However, the consistent signal, strength of forcing, and instability and shear parameter spaces all point to a possible widespread severe threat across the area on Friday. && .AVIATION...(For the 12Z TAFS through 12Z Thursday morning) Issued at 933 AM CDT Wed May 30 2018 Scattered rain showers and thunderstorms will continue this morning across western and north central North Dakota. MVFR ceilings may develop across much of the west and north central this morning. A few IFR ceilings are possible. Patchy fog is also expected this morning across western and north central North Dakota. With daytime heating, scattered thunderstorms are expected across central North Dakota, decreasing through the early evening. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && UPDATE...TWH SHORT TERM...PA LONG TERM...PA AVIATION...TWH
Hazardous Weather Outlook National Weather Service Bismarck ND 952 AM CDT Wed May 30 2018 NDZ001>005-009>013-017>023-025-031>037-040>048-050-051-311500- Divide-Burke-Renville-Bottineau-Rolette-Williams-Mountrail-Ward- McHenry-Pierce-McKenzie-Dunn-Mercer-Oliver-McLean-Sheridan-Wells- Foster-Golden Valley-Billings-Stark-Morton-Burleigh-Kidder- Stutsman-Slope-Hettinger-Grant-Bowman-Adams-Sioux-Emmons-Logan- La Moure-McIntosh-Dickey- 952 AM CDT Wed May 30 2018 /852 AM MDT Wed May 30 2018/ This Hazardous Weather Outlook is for portions of north central North Dakota, northwest North Dakota, south central North Dakota, southeast North Dakota, and southwest North Dakota. .DAY ONE...Today and Tonight Scattered thunderstorms will develop across central North Dakota this afternoon through the early evening. Locally heavy rain and dangerous lightning are expected. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday Two rounds of severe weather are possible across western and central North Dakota Thursday through Friday night. For Thursday, the most likely scenario is for severe thunderstorms to possibly develop across northwest North Dakota late Thursday afternoon or early evening, and possibly move into north central North Dakota during the late evening and overnight. Additional scattered thunderstorms, possibly strong to severe, may develop late Thursday evening and through the night across the southwest and south central. Large hail to ping pong ball size, damaging winds in excess of 65 mph, heavy rainfall, and dangerous lightning are the primary threats. A potentially more widespread, and significant severe weather event is possible Friday afternoon through Friday night across western and central North Dakota. The greatest risk at this time appears to be across the central. All hazards are possible including potentially very large hail, damaging winds, a few tornadoes, and heavy rainfall. Some uncertainty remains, and details will be refined as the event approaches. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed especially across northwest and far north central North Dakota late Thursday afternoon through Thursday night. Spotter activation may be needed across most of western and central North Dakota on Friday. twh
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BISMARCK ND
931 AM CDT WED MAY 30 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0930 AM HEAVY RAIN 5 NW PLAZA 48.07N 102.03W
05/30/2018 M5.50 INCH MOUNTRAIL ND BROADCAST MEDIA
&&The Fargo/Grand Forks radar (KMVX), 123 km away, was scanning. The volume nearest the first event began at 17:16 UTC.
1 tornado. Local standard time, as filed.
This tornado was considered to be a landspout tornado. It occurred over rural areas east-southeast of Bordoulac, and no damage occurred. Therefore, it was rated EF0.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in North Dakota in 2018Every state in 2018This day in weather historyThe tornado archive for North Dakota, 2018Warnings in North Dakota, May 2018
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 754757.