textproduct: Duluth

KEY MESSAGES

- Precipitation returns today through Thursday afternoon. Rain is the most likely precipitation type. A light wintry mix cannot be ruled out in far northern Minnesota, particularly this morning in Koochiching, northern Itasca, and northern St. Louis counties.

- Areas of fog this morning, some of which will be locally dense in inland northwest Wisconsin.

- Drier weather moves in Friday into this weekend with high temperatures 5-10 degrees above normal.

- An active pattern may develop in the early to middle portion of next week, along with a colder than normal airmass moving into central U.S. mid next week.

DISCUSSION

Issued at 321 AM CST Wed Nov 19 2025

This Morning:

Early this morning, surface high pressure is centered over the Great Lakes to southern Ontario, with low pressure over far southern Saskatchewan and Manitoba, gradually moving ENE with time today into Thursday. In the "warm sector" ahead of this low, a weak feed of moisture and isentropic ascent will favor some precipitation moving into far north-central Minnesota first here prior to sunrise, and then gradually expanding east and south with time this morning into most of north-central Minnesota and portions of the Arrowhead. Precipitation type in the 5/6 AM to 10ish AM timeframe in northern Itasca, Koochiching, and northern St. Louis counties will be tricky to pin down. The reason for this is air temperatures are generally around or just above freezing at both the surface and in a near-isothermal layer from the surface up to around 800-750 mb. In addition, some dry air in the low levels of the atmosphere at onset could delay precipitation reaching the ground and even lead to some wet- bulbing of surface temperatures currently above freezing down to around freezing given surface dewpoint depressions of 15F-20F. As a result, this timeframe (5am-10am) could see a few hours of a wintry mix of rain, very light snow, or even spotty freezing rain (20-30% chance) depending on where surface air temperatures settle out. This could produce up to a light glaze of spotty ice accretion (around one hundredth of an inch or less) before temperatures completely warm above freezing later this morning and precipitation changes over to all rain.

Observations also show some areas of fog/dense fog in inland northwest Wisconsin this morning. High-res models do suggest some fog moving north into more of northwest Wisconsin west to the Brainerd Lakes this morning, but confidence in this actually occurring remains low as cloud cover overhead should limit additional fog formation due to radiational cooling despite light winds. We will continue to monitor fog development and possible expansion as the early morning progresses. For now, we have held off on any issuance of Dense Fog Advisories.

Today - Thursday:

Precipitation changes over to all rain starting late this morning aside from rain mixing with very light snow in the Arrowhead at times today. Look for high temperatures in the Northland to top out in the mid to upper 30s in northeast Minnesota and upper 30s to low 40s elsewhere. Temperatures cool down into the low to mid 30s again tonight, so light snow chances mix back in with the rain in the Arrowhead and northwest Wisconsin this evening and tonight, while the remainder of the Northland sees light rain. Some of this snow does linger in northern Minnesota into Thursday morning to around midday as a cold front sweeps east through the Northland. However, precipitation pretty quickly comes to an end from west to east behind the cold front later Thursday morning and afternoon as a cooler and drier airmass works in. High temperatures on Thursday will range from the upper 30s to around 40F in northern Minnesota to 40s along and south of US-2.

Friday - This Weekend:

High pressure moves through the region Friday and Saturday, keeping conditions dry with high temperatures warming from the mid 30s to mid 40s on Friday to widespread 40s on Saturday. There is some weak shortwave energy aloft that moves through with another cool front Saturday night into Sunday, but a lack of moisture availability looks to keep the Northland largely dry with precipitation chances of less than 20%, with the main weather impact with the late weekend front passage being some cloud cover. Sunday's high temperatures will be similar to Saturday in the 40s, about 5F-10F above normal for the second to last week of November.

Early to Mid-Next Week:

Global model ensemble guidance continues to have a fairly medium to high confidence in the weather pattern becoming more active starting in the early to middle portion of next week as broader, deeper troughing aloft sets up across the northwestern to central U.S. This includes a much colder, winter airmass moving into the Upper Midwest by the middle of next week, with high confidence in below average high and low temperatures returning. Despite the higher confidence in colder temperatures by the middle of next week, precipitation chances for early to mid-next week remains lower due to uncertainty in the track and progression of an Alberta Clipper on Tuesday through early Thursday and when or if it merges with a southern stream low pressure/Panhandle hook during that timeframe. Precipitation potential--including snow--during or just prior to the Thanksgiving travel period will be highly dependent on how these low pressure systems track next week.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 545 AM CST Wed Nov 19 2025

As of 1140Z, LIFR to VLIFR ceilings have pushed into some portions of northwest Wisconsin. HYR has stayed north of this so far, but there may be some brief fog and IFR to LIFR ceilings potential there for a few hours early to mid morning. IFR ceilings at BRD should also expand north to DLH and HIB later this morning and afternoon, with brief MVFR at times. INL should also get MVFR ceilings starting this afternoon. Light rain is starting to spread in from the west, already in the vicinity of INL, though dry air in the low-levels has been slow to saturate, delaying more widespread rain reports. Rain eventually spreads across much of the area this afternoon through the end of the TAF period, with the better chances at INL/HIB/DLH. BRD and HYR may see precipitation more in the form of drizzle once we get into later this evening and tonight. Conditions deteriorate further this evening and tonight and we have gone with a more pessimistic forecast of IFR ceilings at BRD/INL and LIFR conditions at HIB/DLH/HYR, with potential VLIFR ceilings at DLH tonight.

Winds remain light and variable to southerly early this morning and then turn southerly after sunrise at 5-10 kt with occasional daytime gusts of 12-16 kt. Winds weaken again after sunset and veer to the southwest.

MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 321 AM CST Wed Nov 19 2025

Light southwest winds this morning will increase today into Thursday morning with gusts of 15-25 kt before turning northwesterly Thursday PM into early Friday with gusts of 10-20 kt. The strongest of these winds will be this evening into mid- Thursday morning from Grand Marais to Grand Portage, where a Small Craft Advisory has been issued for winds up to 25 kt and wave heights building to 2-5 ft. Northwest winds gradually weaken on Friday before turning southwesterly Friday night and picking up a bit again on Saturday.

For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt.

DLH WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None. MARINE...Small Craft Advisory from 6 PM this evening to 9 AM CST Thursday for LSZ140.