An upper disturbance moving across a very moist and unstable air mass generated a cluster of thunderstorms which caused flooding around and north of Ironwood on the 15th. The storm complex also generated damaging wake low winds across portions of west and central Upper Michigan.
Every event with a place to put it; 6 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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 MQT wrote it up.
An upper disturbance moving across a very moist and unstable air mass generated a cluster of thunderstorms which caused flooding around and north of Ironwood on the 15th. The storm complex also generated damaging wake low winds across portions of west and central Upper Michigan.
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 Marquette, MI wrote its last area forecast discussion before the first event at Jun 15, 2:31 AM CST, 1 hour 59 minutes earlier.
Area Forecast Discussion National Weather Service Marquette MI 431 AM EDT Fri Jun 15 2018 .SHORT TERM...(Today and tonight) Issued at 430 AM EDT FRI JUN 15 2018 Main concerns in the short term forecast will be the potential for showers and thunderstorms this morning and again late this afternoon into tonight. Today: The shortwave energy across the northern Plains is expected to continue lifting to the the northeast through the morning hours. While the greatest energy will lift to the north of the U.P., the southern portion of the shortwave will slide through the area. The combination of this energy and strong low-level moisture advection into the area will set the stage for some heavier rain this morning across the west half of the U.P. This can also be noted by PWAT values around 1.5 to 2 inches across the western U.P. this morning. This is nearly double the normal values for this time of year. In addition, lapse rates will steepin as the shortwave slides overhead through the morning hours. This will lead to an increase in instability across the Upper Peninsula. In fact, models are showing about 1000 to 2000 J/KG of MU CAPE early through much of the day. Deep layer effective shear values are expected to be in the 20 to 30 knot range, so it is not out of the question that some of the storms could be strong to severe. The main threats will be hail and gusty winds. Storm motion is expected to be at 25 to 30 mph out of from the west to west northwest with the general motion of the line of storm to the southeast. There may be a bit of break in the action during the early to mid afternoon, but hi-res models solutions are beginning to pick up on yet another shortwave moving into the area during the late afternoon hours over the west. Tonight: The next shortwave along with the associated instability and convection is progged to slide into the western U.P. by around 00Z/16. There are some differences in the model solutions; however, a bit more than half of the them are picking up on this convection during the evening hours. Moisture transport into the area is expected to remain strong through much of the night allowing for the continued heavy rain potential across much of the U.P. PWAT values are expected to continue to be in the 1.5 to 2 inch range across the area as well. This second shortwave will still have the 1000 to 2000 J/KG of MU CAPE to work with along with perhaps a bit better shear in the 25 to 35 knot range. This would lead to an even better chance of severe thunderstorm potential across the area during the evening hours or perhaps even the early overnight hours. Large hail and gusty winds would be the main threat from the strongest storms. Individual storm motion this evening would likely be from the west, while the over line of storms motion would be from the northwest to southeast. .LONG TERM...(Saturday through Thursday) Issued at 314 AM EDT FRI JUN 15 2018 Nam shows a deep 500 mb trough in the western U.S. with a strong 500 mb ridge over the central U.S. and a trough off the east coast 12z Sat. The upper Great Lakes are in the ring of fire scenario at the top of the ridge on Sat through Sun night as the pattern changes very little. Any shortwave that is able to top the ridge will kick off convection, so timing and coverage will be tough to pin down at this point and there will be several rounds of convection that move through this weekend, probably more at night than during the day. Temperatures will be tricky on Sat and Sun and will be very dependent on convection and cloud cover. If there is less convection and cloud cover, not unreasonable to see temperatures in the lower 90s in places. For now, did not make any changes to the temperatures as it seems to take into account some cloud cover and some convection, but the highs will definitely have to be watched. Severe weather is also a threat with wind and hail being the primary threats. In the extended, GFS and ECMWF show a 500 mb ridge in the sern U.S. and a deep trough over the western U.S. with a shortwave over the northern plains and south central Canada 12z Mon. This shortwave moves by on Mon and Mon night with very little change to the overall pattern for Tue. A rex block blocking pattern sets up 12z Wed with a closed low over the Rockies and a ridge in the Canadian Rockies. This ridge builds more into the Canadian Rockies 12z Thu with troughing over the ern U.S. The ridge starts to flatten out as it is pushed southeast towards the Canadian prairies and plains as troughing remains over the ern U.S. 12z Fri. Cool down starts on Mon with the front pushing to the south of the area. && .AVIATION...(For the 06Z TAFS through 06Z Friday night) Issued at 137 AM EDT FRI JUN 15 2018 VFR conditions will prevail overnight at KIWD/KCMX/KSAW, and low- level jet shifting into the Upper Lakes will lead to LLWS at KIWD/KCMX. A disturbance combined with moisture and instability transported ne by the low-level jet will generate shra/tsra to the w, and this pcpn should reach KIWD after daybreak and KCMX around mid morning. Could be some MVFR perhaps brief IFR conditions depending on how hvy the pcpn is. There is still uncertainty in whether the shra/tsra will reach KSAW, so only a VCSH mention was maintained late morning/early aftn. Southerly winds will be gusty to around 20kt or so during the day. Additional shra/tsra may develop during the aftn and evening, but confidence in whether there is any development is much too low right now to include a mention. && .MARINE...(For the 4 AM Lake Superior forecast issuance) Issued at 430 AM EDT FRI JUN 15 2018 Winds will be between 10 to 20 knots through the end of the weekend. A complex of showers and thunderstorm are expected to move across western portions of Lake Superior Friday morning, which may result in areas of fog limiting visibility on Friday. This line of storms may also cause some very gusty erratic winds after they pass, maybe even as high as 35 knots for a brief period. Winds will relax Saturday into early next week with speeds generally around or less than 15 knots, with perhaps a brief uptick towards 20 knots on Monday. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && SHORT TERM...KEC LONG TERM...07 AVIATION...Rolfson MARINE...KEC
Hazardous Weather Outlook National Weather Service Marquette MI 409 AM EDT Fri Jun 15 2018 MIZ001>007-009>014-084-085-161200- Keweenaw-Ontonagon-Northern Houghton-Baraga-Marquette-Alger-Luce- Gogebic-Iron-Dickinson-Menominee-Delta-Southern Schoolcraft- Southern Houghton-Northern Schoolcraft- 409 AM EDT Fri Jun 15 2018 /309 AM CDT Fri Jun 15 2018/ This Hazardous Weather Outlook is for portions of western Upper Michigan and central Upper Michigan. .DAY ONE...Today and Tonight There is a chance of thunderstorms through tonight. A few storms could be severe late this afternoon through tonight and could contain large hail and damaging wind gusts. A few storms could also produce heavy rainfall. .DAYS TWO THROUGH SEVEN...Saturday through Thursday Thunderstorm chances continue through Monday. There is potential for strong to severe storms Saturday through Sunday night with large hail and damaging wind gusts the primary threat. Heavy rain will be possible over west and central Upper Michigan through the weekend with any stronger or persistent thunderstorms. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report any observed hail or wind damage from thunderstorms to the National Weather Service in Marquette. The public may also submit reports to the National Weather Service via phone, on our website, or through Facebook or Twitter. LSZ162-240>251-263>267-161200- Lake Superior west of a line from Saxon Harbor WI to Grand Portage MN beyond 5NM-Saxon Harbor WI to Black River MI- Black River to Ontonagon MI- Ontonagon to Upper Entrance of Portage Canal MI- Upper Entrance of Portage Canal to Eagle River MI- Eagle River to Manitou Island MI- Manitou Island to Point Isabelle MI- Point Isabelle to Lower Entrance of Portage Canal MI- Lower Entrance of Portage Canal To Huron Islands MI Including Keweenaw and Huron Bays-Huron Islands to Marquette MI- Marquette to Munising MI-Munising to Grand Marais MI- Grand Marais to Whitefish Point MI- Lake Superior from Saxon Harbor WI to Upper Entrance to Portage Canal MI 5NM off shore to the US/Canadian border including Isle Royale National Park- Lake Superior from Upper Entrance to Portage Canal to Manitou Island MI 5NM off shore to the US/Canadian Border- Lake Superior West of Line from Manitou Island to Marquette MI Beyond 5NM from shore- Lake Superior East of a line from Manitou Island to Marquette MI and West of a line from Grand Marais MI to the US/Canadian Border Beyond 5NM from shore- Lake Superior from Grand Marais MI to Whitefish Point MI 5NM off shore to the US/Canadian border- 409 AM EDT Fri Jun 15 2018 /309 AM CDT Fri Jun 15 2018/ This Hazardous Weather Outlook is for portions of Eastern Lake Superior...Central Lake Superior and Western Lake Superior. .DAY ONE...Today and Tonight There is a chance of thunderstorms through tonight. A few storms could be severe late this afternoon through tonight and could contain large hail and damaging wind gusts. A few storms could also produce heavy rainfall. .DAYS TWO THROUGH SEVEN...Saturday through Thursday There is a potential for strong to severe storms Saturday through Sunday night with large hail and damaging wind gusts the primary threat. Heavy rain will be possible. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report any observed hail or wind damage from thunderstorms to the National Weather Service in Marquette. The public may also submit reports to the National Weather Service via phone, on our website, or through Facebook or Twitter. LMZ221-248-250-161200- Green Bay North of line from Cedar River MI to Rock Island Passage-Seul Choix Point to Point Detour MI- 5NM East of a line from Fairport MI to Rock Island Passage- 409 AM EDT Fri Jun 15 2018 This Hazardous Weather Outlook is for portions of Northern Lake Michigan. .DAY ONE...Today and Tonight There is a chance of thunderstorms through tonight. A few storms could be severe late this afternoon through tonight and could contain large hail and damaging wind gusts. A few storms could also produce heavy rainfall. Dense fog is expected tonight. .DAYS TWO THROUGH SEVEN...Saturday through Thursday Dense fog is expected through Saturday night. Thunderstorm chances continue through Monday. There is potential for strong to severe storms Saturday through Sunday night with large hail and damaging wind gusts the primary threat. Heavy rain will be possible. .SPOTTER INFORMATION STATEMENT... The need for weather spotter reports is not anticipated at this time. 07
Special Weather Statement
National Weather Service Marquette MI
551 AM EDT FRI JUN 15 2018
MIZ002-009-151030-
Ontonagon MI-Gogebic MI-
551 AM EDT FRI JUN 15 2018
...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN GOGEBIC AND WEST
CENTRAL ONTONAGON COUNTIES UNTIL 630 AM EDT/530 AM CDT/...
At 550 AM EDT/450 AM CDT/, Doppler radar was tracking strong
thunderstorms along a line extending from 9 miles northeast of Odanah
to near Upson. Movement was northeast at 45 mph.
Nickel size hail will be possible with these storms.
Strong thunderstorms will be near...
Hurley around 510 AM CDT.
Ironwood around 515 AM CDT.
Bessemer and Wakefield around 525 AM CDT.
Other locations impacted by these storms include Thomaston, Little
Girls Point, Clark Lake, Van Buskirk and Presque Isle Reservoir.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
If on or near Lake Superior, get out of the water and move indoors
or inside a vehicle. Remember, lightning can strike out to 10 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.
&&
LAT...LON 4662 9042 4681 8996 4687 8987 4689 8969
4625 8963 4633 9011 4650 9022 4650 9027
4652 9028 4651 9032 4656 9034 4654 9035
4654 9040 4657 9042
TIME...MOT...LOC 0950Z 246DEG 38KT 4671 9055 4631 9049
07Special Weather Statement
National Weather Service Marquette MI
510 AM CDT FRI JUN 15 2018
MIZ009-151100-
Gogebic MI-
510 AM CDT FRI JUN 15 2018
...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN GOGEBIC COUNTY UNTIL
600 AM CDT...
At 509 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 6 miles east of Odanah to 6 miles southwest of
Upson. Movement was east at 30 mph.
Nickel size hail will be possible with these storms.
Strong thunderstorms will be near...
Hurley around 540 AM CDT.
Ironwood around 545 AM CDT.
Porcupine Mountains State Park, Bessemer and Wakefield around 600
AM CDT.
Other locations impacted by these storms include Thomaston, Little
Girls Point, Van Buskirk, Ironwood Airport and Copper Peak.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
If on or near Lake Superior, get out of the water and move indoors
or inside a vehicle. Remember, lightning can strike out to 10 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.
&&
LAT...LON 4663 9043 4675 9012 4681 8989 4660 8986
4659 8984 4627 8977 4633 9011 4650 9022
4650 9027 4652 9028 4651 9032 4656 9034
4654 9035 4654 9040 4656 9042
TIME...MOT...LOC 1009Z 257DEG 26KT 4657 9054 4630 9048
07Special Weather Statement
National Weather Service Marquette MI
527 AM CDT FRI JUN 15 2018
MIZ009-151115-
Gogebic MI-
527 AM CDT FRI JUN 15 2018
...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN GOGEBIC COUNTY UNTIL
615 AM CDT...
At 527 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 10 miles north of Saxon to near Upson. Movement
was east at 20 mph.
Dime size hail will be possible with these storms.
Strong thunderstorms will be near...
Hurley around 550 AM CDT.
Ironwood around 600 AM CDT.
Porcupine Mountains State Park, Bessemer and Wakefield around 615
AM CDT.
Other locations impacted by these storms include Thomaston, Little
Girls Point, Van Buskirk, Ironwood Airport and Copper Peak.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
If on or near Lake Superior, get out of the water and move indoors
or inside a vehicle. Remember, lightning can strike out to 10 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.
&&
LAT...LON 4663 9043 4681 8996 4687 8987 4687 8985
4679 8984 4677 8988 4660 8986 4659 8983
4629 8981 4629 8986 4633 9011 4650 9022
4651 9032 4656 9034 4654 9040 4656 9042
TIME...MOT...LOC 1027Z 252DEG 19KT 4664 9037 4633 9035
07The Duluth radar (KDLH), 163 km away, was scanning. The volume nearest the first event began at 10:29 UTC.
6 high wind, 1 heavy rain, 1 hail, 1 thunderstorm wind, 1 flood. Local standard time, as filed.
Approximately two inches of rainfall in two hours from thunderstorms caused minor street flooding in Ironwood.
The spotter in Ironwood observed dime-sized hail from storms.
There was a social media report of several small poplar trees down on Sunset Road in Ironwood Township.
The Gogebic County Sheriff reported vehicles stranded on streets in Ironwood with multiple closures of roads due to flood waters, including Highway US-2 between Lowell Street and Douglas Boulevard. Multiple basements were also flooded in the Ironwood area with estimated rainfall reports between four and five inches. Governor Rick Snyder declared a state of disaster in Gogebic County as damage estimates from the flooding were estimated at nearly $344,000.
Peak wind gust measured at the Brockway Mountain observing site during wake low event.
An NWS employee reported a eight-inch diameter tree down near Rublein Street in Marquette.
A spotter reported half a tree down blocking part of County Road 480, one mile east of the Crossroads in Sands Township.
There was a public report of a snapped aspen tree blocking Cherry Creek Road near Harvey.
There was a public report of power and cell service out in L'anse.
There was a picture on social media of a downed tree two miles west of Trowbridge Park in Marquette. A spotter also reported a tree limb down on a home west of Harvey.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Michigan in 2018Every state in 2018This day in weather historyWarnings in Michigan, June 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: 751814, 751813, 751815, 751816, 759763, 759085, 759084, 759083, 759086, 759080.