


Area Forecast Discussion
Issued by NWS Duluth, MN
Issued by NWS Duluth, MN
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044 FXUS63 KDLH 060839 AFDDLH Area Forecast Discussion National Weather Service Duluth MN 339 AM CDT Sun Jul 6 2025 .KEY MESSAGES... - Seasonal temperatures much of the week with a brief warm up Thursday. - Showers and storms return Monday into Tuesday. A few of these storms could become strong with gusty winds and small hail Monday afternoon and evening. - Additional shower and thunderstorms chances during the latter half of this week into Saturday, some of which could also become strong to severe at times. && .DISCUSSION... Issued at 338 AM CDT Sun Jul 6 2025 Today - Tonight: A largely pleasant day is in store for most of the Northland today in the wake of yesterday`s cold front as more seasonable high temperatures in the 70s are expected for most. A lake breeze today will keep the North Shore, Twin Ports, and portions of northwest WI cooler with highs in the mid to upper 60s. Humidity will be noticeably lower today with dewpoints in the 50s for most and then dropping into the 40s for dewpoints with the lake breeze. Some Canadian wildfire smoke aloft should also mix down to the surface today into this evening, reducing air quality and visibility at times. The best potential looks to be along and north of the Iron Range. A weak shortwave mid/upper level trough sliding through a zonal flow pattern later this afternoon into early tonight may produce some light, stray rain showers/sprinkles (10-20%) for far northern MN, though dry air near the surface should keep it mostly as virga. Little to no accumulations expected. Monday - Tuesday: A stronger mid/upper-level shortwave trough slides through the Northern Plains on Monday and through northern MN Monday night into early Tuesday. Cloud cover increases ahead of this system, with a tongue of 1.25-1.5" of PWAT values nosing into the Northland, which should be a catalyst for shower and thunderstorms in the Northland Monday afternoon into Tuesday. While most of the rainfall is poised to fall Monday evening into Monday night, the instability/shear profile Monday afternoon and evening looks sufficient for a few stronger storms to develop. 0-6km shear around 30-40kt and 800-1400 J/kg of MUCAPE should be enough to produce some semi-organized storm clusters, with isolated gusty winds (40-50 mph) and near severe hail (pennies/nickel size) as the main threats given rather modest low and mid-level lapse rates, along with brief localized heavy rain. Strong storm potential wanes with eastward extent, so the best potential should be across north-central/northeast MN into the St. Croix River Valley. Look for high temperatures both days to be in the 70s to lower 80s, and slightly cooler near Lake Superior. Wednesday - Next Weekend: We see a brief warming trend for Wednesday into Thursday as a shortwave ridge aloft moves across the Upper Midwest, which should push temperatures into widespread 80s away from Lake Superior on Thursday. Can`t rule out some mid-upper 80s with heat indices around 90F in north-central MN on Thursday as the crest of the ridge axis is moving through and the highest dewpoints (mid/upper 60s) would be present. Some mid-level shortwave vorticity and a 30 knot low-level jet Wednesday night/Thursday morning could kick off some showers and storms in north-central MN, but weak shear and instability should keep these as non-severe. More potent moisture advection should then occur later Thursday into Friday ahead of a strengthening upper-level shortwave/low as it crosses the southern Canadian Prairies, bringing PWATs of 1.5-2" into the Upper Midwest once again. Still some decent spread in timing/intensity/track differences among global ensembles with this system, so confidence on exact details on severe thunderstorm and heavy rainfall/flooding potential remains lower at this time. With that said, early indications are that the instability/shear parameter space for Friday/Friday evening could support a severe weather threat should this system track across our area at the optimal time. Regardless, expect a return of precipitation chances (50-70%) late Thursday into early Saturday. Temperatures moderate behind this late week system, with highs back to seasonal values in the 70s to around 80 next weekend. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1248 AM CDT Sun Jul 6 2025 A cold front has moved through the Northland with drier air working into the region in the wake of the front. Some areas that saw rain yesterday could see some areas of MVFR to IFR fog during the current overnight, particularly KHYR. However, as the drier air continues to work in, winds could stay just elevated enough to prevent more than just isolated fog development. Outside of this fog potential, VFR conditions are expected for the remainder of the period with diurnal cumulus developing today with some Canadian wildfire smoke mainly staying aloft. A few showers could affect the KINL vicinity later this afternoon into evening, but drier air near the ground may just evaporate any rain before it reaches the ground. && .MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 338 AM CDT Sun Jul 6 2025 Dense fog along the western Lake Superior waters has lifted, so the Dense Fog Advisory was cancelled. Winds turn northeasterly today at 5-15 kt and gusts to 15-20 kt, becoming strongest along the South Shore and at the head of the Lake where wave heights around 2-3 feet develop today. Winds become light and variable tonight with lower waves before becoming northeasterly again Monday at 5-10 knots with gusts of 10-15 kt. Chances for showers and thunderstorms then return late Monday afternoon into early Tuesday. Additional thunderstorm chances return late this week for late Thursday into Saturday. For the open water discussion, refer to the NWS Marquette Area Forecast Discussion at weather.gov/mqt. && .DLH WATCHES/WARNINGS/ADVISORIES... MN...Beach Hazards Statement from 7 AM CDT this morning through this evening for MNZ037. WI...Beach Hazards Statement from 7 AM CDT this morning through this evening for WIZ001. MARINE...None. && $$ DISCUSSION...Rothstein AVIATION...Rothstein MARINE...Rothstein