textproduct: Marquette

KEY MESSAGES

- Well above normal temperatures persist through Monday. Highs into the 80s are likely over the western UP today and Sunday.

- A Red Flag Warning is in effect for Ontonagon and Gogebic Counties today into Sunday. Elevated fire weather conditions are likely elsewhere across the U.P. today and Sunday.

- Chances for widespread rain showers with light accumulations late Monday afternoon into Tuesday morning.

-Temperatures return to near-normal Tuesday.

DISCUSSION

Issued at 411 PM EDT Sat Oct 10 2026

18Z RAP analysis and GOES visible imagery show a 994 mb low centered over the Northern Plains while sprawling high pressure dominates above New England. This leaves a tightly packed pressure gradient sitting atop Lake Superior and the Upper Peninsula this afternoon. Temperatures in the eastern UP remain mostly below 70F, with southerly flow modified by cooler Lake Michigan SSTs and lingering cloud cover over the east. Most locations in the western UP have already achieved temperatures in the low 80s, with some spots in the mid 80s. Likewise, relative humidities in the east range from 50%- 60%, while those in the far west have dropped to 30%-40%. The upstream 12Z GRB sounding shows dry air (dewpoints to 0C) at 925 mb and very dry air (dewpoints to -20C) at 700 mb. SPC Mesoanalysis shows elevated 925 mb winds of up to 35kt over land areas. With primed HDW conditions and a Red Flag Warning currently in effect for Ontonagon and Gogebic counties and elevated fire conditions elsewhere, we continue to monitor for ongoing wildfires.

As the day reaches its period of peak mixing, expect to see breezy conditions intensify and relative humidities continue to drop. The most recent REFS run continues to highlight areas of the far western and eastern UP, along with the Huron Mountains toward the Lake Superior shoreline, with a 40-90% chance of seeing gusts to 40 mph well into this evening. This is thanks largely to high temperatures allowing mixing with a strong LLJ (100th percentile at 50-60 kts at 925 mb per the REFS) prior to nocturnal PBL decoupling. As observations trend toward the low-end scenario of dryness, can likewise anticipate relatively widespread RH's in the 30-35% range in the western UP to be achieved this early evening. It's a good idea to check with your local DNR restrictions this evening prior to lighting the campfire.

Tomorrow, the Northern Plains low is forecast to weaken and elongate rapidly between northern MN and toward James Bay, resulting in a swath of low pressure to the area's NNW. The pressure gradient eases up slightly tomorrow, though with continued WWA, anomalously high temperatures persist through Monday, with highs and lows 15-30F above normal the rule until Monday night. Lows tonight are forecast in the mid 50s and low 60s and highs tomorrow very similar to today, in the high 70s and low 80s. Winds diminish after late morning tomorrow, followed by lows again tomorrow night near 60F. Tuesday marks a sharp break in the pattern, with the stretched low system descending south across the CWA. Winds shift northeasterly, and precipitation chances for a wetting rain Monday into Tuesday range between 35% and 50%. For later in the week, high pressure looks to move in, though will note that LREF clusters show noticeable spread by only Day 4, so uncertainty remains high for that time period.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 724 PM EDT Sat Oct 10 2026

VFR conditions will prevail at all sites throughout the period. The biggest threat to aviation is LLWS ongoing at CMX/IWD and soon to begin at SAW in response to a low level jet over the UP above a stable surface layer tonight. LLWS ends as atmospheric mixing increases in the morning hours, though the gusty winds out of the southwest will continue, only slowly decreasing throughout the day.

MARINE

Issued at 411 PM EDT Sat Oct 10 2026

Lake Superior: Low-end gale force gusts are observed on eastern Lake Superior this afternoon, with sustained winds over the open lake at 25-30 kt and gusts to 35 kt holding steady since mid-morning. Nearshore observations indicate similar strength winds, consistent with today's southerly regime. Over the western arm, winds are southeasterly at 10-15kts. This evening and tonight, waves will be 4- 9 ft (highest offshore) in the east and 2-3ft in the west. Sunday afternoon, winds lighten to 10kts and shift southwesterly over the western arm while winds remain at 15-20kts and southerly in the east. Waves will be 1-3ft. Monday morning, winds shift northeasterly and increase up to 35kts with wave heights building to 5-7ft in the afternoon. Gales are possible, particularly in the western arm, with frequent gusts to 35 kt and waves to 9ft. Tuesday, wind speeds decrease to 15-20kts but remain northerly with wave heights from 3 to 5ft. Winds look to decrease further into the midweek period.

Northern Green Bay and northwestern Lake Michigan: Winds have built to 20 kt sustained (gusts to 25 kt) throughout the day while veering southeasterly to southerly. Winds are expected to remain elevated into the evening, before diminishing to 10-15 kt sustained (gusts to 25 kt) by sunrise Sunday morning. Some gale-force gusts are not out of the question on the Lake Michigan side through this evening. Waves will be 2-3ft in the bay, 4-8ft in northern Lake Michigan into Sunday. Winds remain somewhat elevated through Sunday (10-15 sustained with gusts to 20 kt), while wave heights remain at 2-3ft for the bay and 3-5ft over northern Lake Michigan. Winds continue to decrease through Sunday night, reaching 10-15kts by Monday morning with 0-2ft waves. Monday afternoon, winds shift to northerly and increase up to 15 kts as a cold front moves through the area. Tuesday, northerly winds continue near 20 kts with 2-3ft waves.

FIRE WEATHER

Issued at 411 PM EDT Sat Oct 10 2026

A Red Flag Warning remains in effect for Ontonagon and Gogebic Counties for critical fire weather conditions today and Sunday. Elevated fire weather conditions are expected elsewhere across the U.P. this weekend. Highs are reaching into the mid-80s in the interior west (mid-70s east), with the same expected for Sunday. RHs will bottom out around 30-35% for most locations over the western UP (over 45% to the east) this afternoon, and 35-40% over the west (55- 60% east) tomorrow. Recovery Saturday overnight will be moderate, with RHs increasing to 60-70%, and very good Sunday night (90-100%). Southerly winds at 10-15mph (gusts up to 35mph in the west) remain elevated well into the evening tonight prior to diminishing slightly prior to sunrise. After a brief period tomorrow morning of elevated winds similar to today, winds start to diminish Sunday morning, falling to gusts to 15 mph by the nighttime. The next chances of rainfall occur Monday into Tuesday, with 30-50% chance of more than 0.25" 2pm Monday through 2pm Tuesday, and 60-90% chance of more than 0.10" during the same time frame. Northeast flow and cooler temperatures take hold late Monday, with highs Tuesday projected to be in the 50s across the UP.

Minimal recent rainfall and ongoing drought conditions make ignition more likely. Any fire that develops could catch and spread quickly. Members of the public should obey local burn restrictions and report any wildfires by calling 911. Fire partners should continue to monitor forecast updates.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Red Flag Warning until 6 PM EDT /5 PM CDT/ Sunday for MIZ002- 009.

Lake Superior... Gale Warning until 2 AM EDT Sunday for LSZ248>251-266.

Lake Michigan... None.