textproduct: Marquette

KEY MESSAGES

- Rainfall has returned and will continue through Friday as a deepening low pressure system works through the Great Lakes, bringing periods of rain and gusty N to NW winds across the area.

- Hazardous marine weather is expected Friday. Northerly gales to 45 kts are expected, creating significant wave heights between 13-17 ft.

- Dry air and increasing winds Saturday and Sunday could bring elevated fire weather concerns back across Upper Michigan over the weekend.

DISCUSSION

Issued at 217 PM EDT Thu Oct 15 2026

As a low digging down from Lake Winnipeg phases with another low lifting from the Central Plains this afternoon, radar imagery shows rainfall beginning to move into the far west by Ironwood as of the time of this writing. As the lows become a new, phased low over Lower MI and Lake Huron tonight, expect the rainfall to continue across the rest of the U.P. the rest of this afternoon through this evening, with generally light rainfall seen across the entire area over the next 12 hours. Within the synoptic phase of this system, expect a wetting rainfall across the area as guidance shows generally around half an inch of liquid falling. However, as robust CAA cycles down behind the phased low late tonight through Friday, expect lake enhanced rainfall to pick up over the north wind belts, eventually transitioning over to pure lake effect rain showers by Friday as the low pulls away and delta-Ts in the mid to upper teens keep the lake effect going until high pressure ridging returns Friday night through this weekend. Additional rainfall amounts from the lake enhanced and effect rain showers late tonight through Friday could bring an additional half inch or more of liquid to the north wind belts, with some of the higher elevations in the upslope areas potentially seeing a 15 to 40% chance of seeing an inch and a half of liquid between now and early Friday afternoon (according to the latest REFS run). With high pressure ridging returning for the weekend, expect the last of the lake effect rain showers to wrap up by Friday night. One last note on the lake effect showers: there could be a transition over to snowfall as the lake effect showers wrap up Friday night. While accumulations should practically be nothing, it is worth noting that these could be the first snowflakes of the season.

With precipitation looking to stay away from the area this weekend through the first half of next week, the WAA seen with the high pressure ridging moving overhead could induce elevated fire weather conditions across the area this weekend, particularly over western Upper MI. This is due to very dry air coming in above the boundary layer (think 925mb level); with mostly sunny skies overhead, robust mixing during the daytime hours could bring RHs down into the 20 percents (lowest on Saturday) and southwesterly wind gusts of 30 to 40 mph to the sfc (strongest on Sunday). In addition, poor RH recoveries are expected over the western U.P. Saturday night (<80% MaxRH). While the recent rainfall will help alleviate drought concerns, with plenty of dead leaves being added to the sfc and the drought conditions not expected to be completely removed after the rainfall this afternoon through Friday, we could see some critical fire weather concerns this weekend across the area. Therefore, as reminder, you should obey all burn bans in place if you are under one (which can be found at www.dnr.state.mi.us/burnpermits). In addition, avoid power equipment that creates sparks, and for smokers, please properly discard your cigarettes, cigars, etc. While the fire weather danger decreases once we enter the first half of the work week next week due to calmer winds, we could see some fairly dry sfc conditions still on Monday and Tuesday (MinRHs down to 30%). Rainfall may finally return by the latter half of next week.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/

Issued at 121 PM EDT Thu Oct 15 2026

A storm system moving through the Great Lakes region will bring widespread rain and low level moisture to the U.P. this afternoon into Friday. Expect MVFR/VFR conditions to deteriorate as the afternoon progresses with widespread LIFR by this evening and VLIFR cigs at CMX. Winds shift north overnight which will help start to lift cigs with improvements to IFR by Friday morning. Widespread rain pushes out during the morning but lake effect rain showers will develop along with gusty northerly winds to 30kt. Conditions will be mainly MVFR by early Friday afternoon as drier low levels help to lift cigs.

MARINE

Issued at 217 PM EDT Thu Oct 15 2026

Lake Superior: Light winds of 20 kts or less this afternoon into this evening rapidly increase to high-end northerly gales up to 45 kts Friday morning as robust CAA drops down across the area. Because of the strong winds and waves building up to 13 to 17 ft (highest over southeast lake), a Gale Warning has been issued for the entire lake Friday. In addition, while not expected, there is up to a 15% chance that a storm force gust or two could be seen in the southeastern lake near Marquette and at the tip of the Keweenaw Friday morning into mid Friday afternoon. As high pressure ridging returns Friday night, expect the winds to die down to 20 kts or less late. However, with the pressure gradient over the lake tightening and a LLJ coming in this weekend, expect winds to pick up from the southwest once again by Saturday to 20 to 30 kts, with the latest REFS showing a 30 to 60% chance for low-end gales over the west half of the lake on Saturday (highest chances along the Bayfield Peninsula followed by the Keweenaw). Gale chances could increase between the Keweenaw and Isle Royale on Sunday as the latest LREF shows up to a 40 to 80% chance of low end gales by then. As the pressure gradient weakens overhead and high pressure ridging builds once again over the Upper Great Lakes, expect the winds to die down to 20 kts or less by Monday morning, remaining that way through the first half of the work week next week.

Northern Green Bay and northwestern Lake Michigan: Light winds of 15 kts or less this afternoon into this evening give way to northerly gales up to 35 kts by late Friday morning as strong CAA drops down from Canada across the Upper Great Lakes. While this will immediately be followed up with high pressure ridging moving in Friday night (which will bring lighter winds of 15 kts or less back across the area), with a tightening pressure gradient and LLJ returning to the area for the weekend, expect winds to pick up from the southwest to 20 to 30 kts, with a 20 to 50% chance of gales up to 35 kts possible on Sunday according to the latest LREF. However, once the pressure gradient weakens early next week and high pressure ridging builds once again over the Upper Great Lakes, expect the winds to drop back down to 15 kts or less again by Monday morning, remaining that way through the first half of the work week next week.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... Gale Warning from 5 AM EDT /4 AM CDT/ to 2 PM EDT /1 PM CDT/ Friday for LSZ162-240.

Gale Warning from 5 AM EDT /4 AM CDT/ to 4 PM EDT /3 PM CDT/ Friday for LSZ241-242-263.

Gale Warning from 5 AM to 5 PM EDT Friday for LSZ243-244-264.

Gale Warning from 6 AM to 9 PM EDT Friday for LSZ245>248-265.

Gale Warning from 6 AM to 11 PM EDT Friday for LSZ249>251-266- 267.

Lake Michigan... Gale Warning from 9 AM to 10 PM EDT Friday for LMZ221-248-250.