textproduct: Duluth

KEY MESSAGES

- Transient dense fog around the Twin Ports and Lake Superior will reduce visibility early this morning but will come and go.

- Steady, moderate rain through tonight will keep water levels high in the Arrowhead where a Flood Watch remains in effect.

- A very low-end threat for an isolated strong storm exists this afternoon in northwest Wisconsin.

- Cooler and progressively drier conditions arrive Tuesday through Friday, bringing low afternoon humidity and possibly fire weather concerns until we green up.

DISCUSSION

Issued at 1253 AM CDT Mon Apr 27 2026

Early this morning, transient dense fog will impact the Twin Ports and western Lake Superior, prompting a Dense Fog Advisory. The fog will come and go rather than being pure soup.

A fairly weakly forced Colorado low pressure system with a rich moisture tap of 1+ PWATs will bring steady rain with moderate rates spreading across the Northland through the day. We have trended lower on the overall precipitation amounts following recent model trends more towards an inch rather than two inches, especially in the ensemble guidance, and the Excessive Rainfall Outlook has been removed after coordination with WPC due to lighter than expected precipitation rates as thunderstorms activity should be further south. Despite the lower expected rainfall totals, the steady and moderate rain will fall on already elevated rivers and streams fresh out of spring runoff from melting snowpack. Local resorts are reporting high lake levels on the Gunflint Trail, so the Flood Watch remains in effect for the Arrowhead through Tuesday morning as water levels will remain high or increase. As for thunderstorms, we are not really excited about any severe threat due to a lack of instability. Most of the energy stays south, except for a brief window this afternoon across northwest Wisconsin where a very low-end threat exists for some hailers. Soundings show tall, skinny CAPE peaking around 700 J/kg in Price County with 35 knots of effective shear which may be enough to muster an isolated threat which matches the SPC outlook.

Rain will taper off from west to east late tonight into early Tuesday morning as the system exits. Winds will shift to the northwest and become blustery for Tuesday, keeping temperatures on the cooler side with highs mostly in the 50s. Dewpoints will drop significantly as drier air filters into the region.

For Wednesday through Friday, expect a quiet but cooler stretch of weather. We have trended progressively drier with afternoon dewpoints each day, utilizing lower percentile guidance. Highs will remain in the 50s with overnight lows dipping near or below freezing. By next weekend, a warming trend arrives with high temperatures climbing back into the 60s under mostly sunny skies, while precipitation chances remain isolated.

The Climate Prediction Center indicates a high probability for below normal temperatures across the Upper Midwest and Great Lakes region heading into the 6-10 outlook period. Precipitation signals generally favor below normal precipitation for the western Great Lakes as anomalous troughing sets up over the eastern CONUS with a drier northwest flow pattern over our area.

AVIATION /06Z TAFS THROUGH 06Z TUESDAY/

Issued at 1253 AM CDT Mon Apr 27 2026

Widespread MVFR to IFR conditions will overspread the TAF sites early this morning as steady rain and lower ceilings move into the region. Transient dense fog will also impact KDLH early this morning. Rain continues through the day with occasional reductions in visibility. A very isolated thunderstorm cannot be ruled out at KHYR this afternoon, but confidence is too low to include prevailing thunder. Conditions will begin to slowly improve to MVFR and VFR late tonight into Tuesday morning as winds shift to the northwest and become gusty.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 1253 AM CDT Mon Apr 27 2026

Transient dense fog will impact western Lake Superior early this morning but should remain patchy rather than a solid wall of zero visibility. We have started Small Craft Advisories earlier across the nearshore waters as northeast winds have already come up. Winds will shift to the northwest late tonight and into Tuesday. Gales still look possible Tuesday morning, with a Gale Watch remaining in effect for gusts reaching 35 to 40 knots, mainly along the North Shore and Twin Ports.

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

FIRE WEATHER

Issued at 1253 AM CDT Mon Apr 27 2026

Widespread rain today and tonight will keep fire weather concerns minimal in the short term. However, we have trended progressively drier with afternoon dewpoints for Tuesday through Friday behind the departing system. Blustery northwest winds on Tuesday combined with the lowering relative humidity may bring near-critical fire weather conditions back to the area, depending on how quickly fine fuels dry out after the rain. Winds will become lighter for the second half of the week.

See the Fire Weather Forecast product for a more thorough breakdown of fire weather conditions.

DLH WATCHES/WARNINGS/ADVISORIES

MN...Flood Watch from 10 AM CDT this morning through Tuesday morning for MNZ012-020-021. Dense Fog Advisory until 9 AM CDT this morning for MNZ037. WI...Dense Fog Advisory until 9 AM CDT this morning for WIZ001. MARINE...Small Craft Advisory from 4 AM to 1 PM CDT Tuesday for LSZ121- 148. Dense Fog Advisory until 7 AM CDT this morning for LSZ140>146. Small Craft Advisory until 4 AM CDT Tuesday for LSZ140>144. Gale Watch from late tonight through Tuesday afternoon for LSZ140>144. Flood Watch from 10 AM CDT this morning through Tuesday morning for LSZ142. Small Craft Advisory until 1 PM CDT Tuesday for LSZ145>147-150.