textproduct: Duluth

KEY MESSAGES

- Rain showers and perhaps a few rumbles of thunder today (60-80%) and again Thursday into Friday (50-70%).

- Briefly cooler today in spots before warming into the weekend with highs in the 70s to low 80s by Friday.

- Minor flooding continues in the Minnesota Arrowhead and along the International Border this week.

- Near-critical fire weather conditions are expected Thursday and Friday due to low humidity and gusty winds.

DISCUSSION

Issued at 322 AM CDT Tue May 12 2026

Early this morning, a low pressure system approaching from the west has brought a round of rain showers and isolated thunderstorms to the Northland. The strongest storms so far have been producing some small hail. We have mid level lapse rates of 7 to 8 C/km as of early this morning. These steep lapse rates remain over the area through this morning, but then slide to our southeast for this afternoon. This should help limit most of our thunder probabilities to these morning hours, then diminishing for the afternoon and evening. The cold air aloft and steep lapse rates will continue to support some small hail production this morning, but severe storms are not anticipated at this time. This should also cause our coverage of showers to be highest this morning, also diminishing through the afternoon and tonight. Highs today will be cooler with the extra cloud cover and precipitation chances, ranging from the 40s and low 50s for the Arrowhead, to the mid 50s to mid 60s elsewhere.

Conditions quiet down tonight as high pressure begins to build in from the west, with a few showers lingering overnight across our east. Winds will shift to the northwest and remain somewhat breezy, especially near the lake. Lows will drop into the 30s for most of the region. Wednesday looks to be a very pleasant day across the Northland under full sunshine. High pressure centered over the area will keep winds lighter and allow temperatures to climb into the 60s to near 70, though it will be 5 to 10 degrees cooler along the Lake Superior shoreline.

The low pressure system which moves from Manitoba into Ontario still looks on track to drag a cold front across the region Thursday into Friday. This system will drag some warm air into the region for both days, with highs by Friday into the 70s to low 80s. In fact, it creates the potential for near critical fire weather conditions on both days. Thursday it is due to breezy southerly winds and low RH values, then on Friday winds turn westerly and are gusty again, with low RH values once again. The cold front itself will bring a chance for rain showers and storms Thursday afternoon and night into Friday. If the front timing shifts to a daytime passage, we could be looking at reduced fire weather concerns, but then storms could be much stronger.

Not much has changed for the weekend forecast, Saturday currently appears to be mostly sunny and dry with highs remaining in the 60s and 70s. Precipitation chances increase again for Sunday into Monday as our upper level pattern finally shifts away from the northwest flow to a more amplified one with troughing over the western states and southwest flow over the upper midwest. This should give us some more precipitation chances along with warmer temperatures.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 633 AM CDT Tue May 12 2026

A low pressure system just west of the area this morning will move across the terminals this morning and early afternoon. Ahead of the low, conditions are predominantly VFR, with a band of showers and storms which have affected a few of the terminals with a brief period of heavier rain, reducing visibilities to MVFR. As the low pressure system passes across the area during the day today, winds will switch directions from generally southeast, to west and then northwest by the end of the TAF period. It will also be followed by gradually lowering ceilings, generally dropping to MVFR for most of the area, advancing from northwest to southeast from mid morning through early afternoon. Once in the northwest flow behind the low pressure system, there will also be scattered showers with MVFR visibilities across most of the terminals. Most of these showers should decrease in coverage during the evening as winds decrease for the overnight time frame.

MARINE /FOR NEARSHORE WATERS OF WESTERN LAKE SUPERIOR/

Issued at 329 AM CDT Tue May 12 2026

A Small Craft Advisory has been issued for parts of western Lake Superior north of Taconite Harbor today and this evening. East to northeast winds gusting up to 25 knots this morning to gradually back to northeast this afternoon and then north tonight before decreasing again. Waves should reach 3 to 5 feet this morning, then diminish this afternoon and tonight.

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

FIRE WEATHER

Issued at 322 AM CDT Tue May 12 2026

Rain and isolated thunder chances along with RH values generally above 40 percent today to help keep fire weather conditions minimized today. Only light accumulations are expected, but a few spots could see a couple tenths of an inch from moderate rain under storms. Dry conditions return Wednesday with minimum relative humidity values below 35 percent, though winds will be northwest to north with gusts up to 20 mph. A more significant fire weather threat may develop Thursday into Friday as southerly winds gust over 30 mph amid warm temperatures and low humidity.

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

DLH WATCHES/WARNINGS/ADVISORIES

MN...None. WI...None. MARINE...Small Craft Advisory until 11 PM CDT this evening for LSZ140- 141. Small Craft Advisory until 10 AM CDT this morning for LSZ143>146.