textproduct: Marquette

KEY MESSAGES

- Potentially historic blizzard is expected late tonight through Monday night. This will create treacherous and potentially life-threatening travel conditions and could result in tree damage and power outages!

- Snow amounts of 1-3 feet are expected (locally up to 4 feet north-central and eastern U.P.) with wind speeds of 35-65 mph. Strongest winds are expected late Sunday afternoon into Monday in the Keweenaw Peninsula and along the lakeshores of Lake Superior.

- Widespread northeast Gales over Lake Superior on Sunday become northerly storm force winds of 50-60 knots Sunday night into Monday. There is a 30% chance for gusts exceeding 64 knots in the east on Monday. Heavy freezing spray is also expected.

- Large waves on the Great Lakes increase the risk of beach erosion and lakeshore flooding for all Lake Superior lakeshores Sunday night and Monday.

DISCUSSION

Issued at 433 PM EDT Sat Mar 14 2026

The primary focus with this forecast is the potentially historic, record-breaking blizzard that will impact the Upper Great Lakes late tonight/early Sunday morning through Monday night. The prolonged nature of very strong winds and quickly accumulating, blowing, and drifting snow will result in treacherous and potentially life- threatening travel conditions and the risk of power outages Sunday and Monday. Please take advantage of today's pleasant weather to finish any pre-storm preparations. Travel should be restricted to emergencies only Sunday and Monday!

High pressure over the Great Lakes today gives us a quiet before the storm. Temps this afternoon will be in the upper 20s to mid 30s with light winds (gusts mostly below 15 mph). Partly cloudy skies fill in later today from the southwest and dry weather persists until tonight.

A vigorous shortwave ejects out of the Rockies this evening, organizing a surface low over the Plains. This system tracks to near Chicago by Sunday evening, then proceeds slowly northeastward somewhere over lower Michigan Sunday night. The shortwave then takes on a negative tilt near western Lake Michigan early Monday and pivots north-northeast with strong vorticity advection over the east half of the CWA and Lower MI. This alongside favorable jet dynamics strengthen the low to near 980 mb Monday morning. There remains a frustrating spread in the low track and a lesser bit of variability in surface low strength beyond Sunday evening, but big picture changes to the forecast due to these uncertainties would be significant impacts or worse...the message remains the same. Ample moisture accompanies this system, noted in 700 mb specific humidity on NAEFS from the west atmospheric river and stronger lower level moisture transport from the Gulf from a strengthening LLJ.

Strong lift is present in the combination of jet entrance regions, isentropic ascent, robust WAA, and 700 mb f-gen late tonight into Sunday morning. This lifts in heavy snowfall rates of 1-3 inches per hour over the UP between 6-10 Z Sunday. Snow then continues through Monday before tapering down Monday night into Tuesday as the surface low lifts to Quebec while extending bent back surface troughing into eastern Upper Michigan. 850 mb temps near -10C cool as additional CAA builds overhead, bringing 850 mb temps down to near -22 C by Tuesday morning. Because of ample synoptic, lake enhanced, and orographic forcing, and model sounding DGZ depths near or greater than 10 kft for long periods of time, guidance is suggesting widespread 1 to 3 ft of snow through the event with localized amounts up to 4 ft in the north-central and eastern U.P. The heaviest snowfall rates will occur on Sunday, particularly the eastern two thirds of the U.P. Snowfall rates of 0.5 to 1.5 inch per hour are favored through Monday evening, heaviest over the north central. Despite the rates being lower (still high) during the latter half of the event, blizzard conditions are still expected as northerly winds increase even further for Sunday night and Monday.

East-northeast winds begin increasing on Sunday, peaking near 40 mph for most inland locations and 50+ mph in the terrain of the Keweenaw and by the lakeshores by evening. Sunday night into Monday will see these winds increase further from the northeast to north, when 60+ mph gusts are expected in the Keweenaw and by Lake Superior with 40- 50 mph being possible elsewhere. The 12z EPS suggests 20-50% chances for winds exceeding 74 mph along the lakeshore from Big Bay to Whitefish Point Monday and 10-30% chances for interior eastern areas. Should these winds occur, tree damage and power outages should be expected. Northerly to northwesterly winds are expected to lighten Monday night, but still remain elevated near Lake Superior into Tuesday morning. Strong winds over Lake Superior build wave heights of up to 20-30 ft, highest over the central third of the lake. Opted to hoist Lakeshore Flood Warnings and a Lakeshore Flood Advisory Sunday night and Monday. These strong winds will also result in snow drifts of several feet tall, adding to difficult travel and snow load on structures.

Opted to upgrade Winter Storm Warnings to Blizzard Warnings CWA wide given the prolonged period of heavy snowfall rates and strong winds resulting in low vsibilities. Impacts from prior storms this week, heavy snowfall rates, blowing and drifting snow will drag on significant travel impacts into early next week.

Lake effect snow looks to continue into Tuesday over the northwest winds snowbelts, diminishing from west to east as high pressure ridging moves in from the west and WAA aloft weakens delta-Ts. Additional amounts Monday night and Tuesday should remain on the light side.

Behind the storm, polar air will keep below normal temperatures across the region, with highs Monday and Tuesday only getting into the teens to lower 20s and lows Monday and Tuesday nights dropping down into the single digits in the interior to lower teens near the Great Lakes. Wind chills will also fall to near -10F during the overnight hours Monday and Tuesday nights. A weak clipper may also bring another shot of snow Wednesday before we warm back up closer to normal for the rest of the week.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 122 PM EDT Sat Mar 14 2026

VFR conditions continue with light winds through this evening. A major winter storm with blizzard conditions will impact all of the terminals beginning after midnight tonight, with heavy snow and high winds continuing through Monday before gradually tapering off Monday night into Tuesday. Snowfall will begin around 05Z at IWD, spreading to SAW around 08Z and CMX 10Z. There is high confidence in visibility falling below airport minimums at SAW/CMX by the mid to late morning hours as snowfall rates reach 1-2" per hour and winds gust to 25-30 knots. There is also a possibility of visiblity below airport minimums at IWD with a PROB30 to address that potential. All told, snowfall will total 1 to 3 feet through Monday night, highest at SAW. Northeasterly to northerly winds will keep increasing after the 18Z TAF period, gusting to 40-50 knots at CMX/SAW Sunday night into Monday, with 30-35 knots possible at IWD, resulting in extreme blowing and drifting of snow and whiteout conditions.

MARINE

Issued at 433 PM EDT Sat Mar 14 2026

A very strong to historic storm moves through the Upper Great Lakes Sunday and Monday. This will result in increasing winds Sunday, reaching Gales in the morning and then Storms Sunday evening. Guidance continues to hold a low (~30% chance) for hurricane force winds on Monday over the east half of the lake. In addition to the strong winds, cold air descending overhead will create heavy freezing spray; additional warnings for heavy freezing spray are anticipated with the next forecast package. Upgraded the Storm Watches to Storm Warnings and included the far western arm as well. Winds diminish Monday night, falling below gales lakewide Tuesday morning.

A clipper low moves through the region Wednesday, resulting in southerly winds of 20 to 30 kts across the lake during the morning/early afternoon hours before falling below 20 kts Wednesday evening.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Blizzard Warning from 5 AM Sunday to 2 AM EDT Tuesday for MIZ001-003>005.

Lakeshore Flood Warning from 8 PM Sunday to 11 PM EDT Monday for MIZ001-003.

Blizzard Warning from 2 AM EDT /1 AM CDT/ Sunday to 8 PM EDT /7 PM CDT/ Monday for MIZ002-009>012-084.

Lakeshore Flood Warning from 11 PM Sunday to 5 PM EDT Monday for MIZ002.

Lakeshore Flood Warning from 8 PM Sunday to 2 AM EDT Tuesday for MIZ005.

Blizzard Warning from 5 AM Sunday to 8 AM EDT Tuesday for MIZ006-007-013-014-085.

Lakeshore Flood Warning from 8 PM Sunday to 8 AM EDT Tuesday for MIZ006.

Lakeshore Flood Warning from 5 AM Monday to 2 AM EDT Tuesday for MIZ007.

Lakeshore Flood Advisory from 10 PM Sunday to 4 PM CDT Monday for MIZ009.

Lake Superior... Gale Warning from 8 AM EDT /7 AM CDT/ to 8 PM EDT /7 PM CDT/ Sunday for LSZ162-240>242-263.

Storm Warning from 8 PM EDT /7 PM CDT/ Sunday to 11 AM EDT /10 AM CDT/ Monday for LSZ162.

Storm Warning from 8 PM EDT /7 PM CDT/ Sunday to 2 PM EDT /1 PM CDT/ Monday for LSZ240>242-263.

Gale Warning from 11 AM to 8 PM EDT Sunday for LSZ243>251- 264>267.

Storm Warning from 8 PM Sunday to 2 AM EDT Tuesday for LSZ243>251-264>267.

Lake Michigan... Gale Warning from 8 AM to 8 PM EDT Sunday for LMZ248-250.

Storm Warning from 8 PM Sunday to 4 PM EDT Monday for LMZ248- 250.