textproduct: Duluth

KEY MESSAGES

- Lake effect snow showers to gradually diminish this afternoon and evening.

- Colder than normal temperatures Tuesday morning with lows dropping near or below zero.

- The next chance of precipitation will be Tuesday night into Wednesday. Mostly rain is expected but there is potential for mixed precipitation and a glaze of ice.

- A more substantial system is expected over the weekend into early next week.

DISCUSSION

Issued at 356 PM CDT Mon Apr 6 2026

High pressure is building into the Northland this afternoon, with a much colder and drier airmass moving in. Clouds have cleared for a large portion of the area this afternoon, with only some lingering, predominantly diurnal cumulus clouds over parts of northwest Wisconsin downstream from Lake Superior. North to northwest winds remain breezy with gusts up to 25 mph, reinforcing the much cooler air, which has stalled temperatures in the mid 20s to low 30s so far. A few scattered flurries or light snow showers remain possible from our lingering cloud cover through sunset, particularly along the higher terrain of the South Shore where weak lake effect processes are ongoing.

For tonight, skies will fully clear as a robust ridge of high pressure builds in from Manitoba. This setup, combined with the fresh snowpack and a very dry air mass, provides ideal conditions for radiational cooling. Temperatures will plummet well below seasonal normals, with most areas dropping into the single digits. Typical cold spots in the interior North and the Iron Range could see values dip below zero, with some sites approaching record low temperatures for the date. Curiously, the NBM gave us overnight lows between the 50th and 75th percentile, which seems counter intuitive. Have bumped overnight lows down to between the 25th and 50th, and lowered some of our typical cold spots even more. This is on the low end of the raw and MOS guidance.

Tuesday starts clear and cold, but the surface high will quickly slide east by the afternoon. This will allow southerly return flow to set up, initiating a warming trend that will push highs back into the 30s to near 40. The quiet weather is short- lived as a clipper- like system tracking along the international border approaches Tuesday night. Expect cloud cover to increase through the afternoon and evening with precipitation chances ramping up after midnight. Thermal profiles suggest we will start out with a wintry mix which transitions to all snow overnight. However, during the early morning hours, a surge of more warm air advection transitions precipitation back to mostly rain Wednesday morning. This warm surge may bring enough instability into the region to generate some rumbles of thunder, but have left out for now. Significantly warmer temperatures can be expected, with highs reaching the 40s and 50s.

A more substantial storm system appears likely for the weekend into early next week. Highs by Saturday and Sunday could surge into the 50s on Saturday, then mid 50s to mid 60s for Sunday. This next system will have a substantial feed of moisture from the Gulf, raising the potential for a soaking rainfall and some rumbles of thunder across the region Saturday night through Sunday and into Monday.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 627 PM CDT Mon Apr 6 2026

VFR through the TAF period. North winds gusting to 20 kt will decouple after sunset and become calm before turning to the south on Tuesday and increasing.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 356 PM CDT Mon Apr 6 2026

Small Craft Advisories remain in effect for the South Shore and Apostle Islands through 9 PM this evening due to northwest gusts to 25 knots and waves up to 5 feet. Conditions improve tonight and Tuesday as high pressure crosses the lake. Stronger south to southeast winds develop early Wednesday ahead of an approaching low, which may require new Small Craft Advisories for the North Shore as waves build to 3 to 5 feet.

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 until 9 PM CDT this evening for LSZ147- 148-150.