152 FXUS63 KDLH 140919 AFDDLHArea Forecast Discussion National Weather Service Duluth MN 419 AM CDT Sun Sep 14 2025
.KEY MESSAGES...
- Areas of fog and low clouds will spread over portions of the Northland before sunrise, and clear out through the morning hours.
- Unseasonably warm and summer-like temperatures are expected through Wednesday. Highs in the 70s to low 80s.
- On-and-off chances for showers and storms for the next week, beginning tonight.
&&
.DISCUSSION... Issued at 313 AM CDT Sun Sep 14 2025
With continued east to northeast winds across western Lake Superior, low clouds and fog have formed again tonight at the head of the lake extending westward south of US-2 and across northwest Wisconsin. Satellite trends show the low stratus now expanding northward, with patchy fog mixed in. Low clouds and fog will lift through the morning hours today, much like the last few mornings.
An upper level ridge over the region will slowly shift eastward today, with southerly low and mid level winds continuing to advect warmer air and moisture northward. This will help push temperatures today into the 70s and lower 80s, except for along the immediate shorelines where temperatures warm into the 60s. A strong shortwave will pivot northward through the Plains today and into south central Canada. This will bring showers and a few storms to the Northland tonight, mainly south of US-2. There is weak elevated instability with bulk shear values of 25=30kts, so cannot rule out a thunderstorm or two, but severe storms are not expected. Shower/storm coverage expands Monday to much of the area. Drier air under the ridge will keep portions of the Arrowhead and northwest Wisconsin dry.
By Tuesday, the upper level continues to be pushed eastward as troughing pushes toward the Upper Mississippi River Valley, keeping the Northland under persistent southwesterly flow through much of the week, with above normal temperatures and humidity the result. Impulses rotating through the trough will allow for periods of rain and thunderstorms. There is some model inconsistency with the timing of these impulses, which would determine when the better rain chances occur. Latest model guidance suggests a large upper low will break from the upper trough and spin over the area the end of the week, bringing the best rain chances to the Northland Thursday and Friday. The upper low would also bring a return to normal temperatures.
&&
.AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 1242 AM CDT Sun Sep 14 2025
Low stratus along the southern shore of western Lake Superior and over the Twin Ports is spreading inland tonight, with east winds at 5-8kts. Cigs at DLH have dropped to LIFR heights, and expect the low stratus to continue to spread north and west, impacting HIB and BRD before sunrise. With the stratus, fog is also possible at DLH with vis below 1 mile.
Conditions improve through the morning Sunday, with improving cigs and vis. Winds will increase from the east, with gusts up to 18kts during the day at all terminals.
&&
.MARINE /FOR NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR/... Issued at 313 AM CDT Sun Sep 14 2025
Areas of low stratus and fog have developed tonight, and will slowly lift through this morning. The worst visibilities will be in the southwestern tip of the lake near the Twin Ports. A dense fog advisory remains in effect through 10AM, for the South Shore and the Twin Ports, but it may need to be expanded to additional areas before sunrise.
Breezy northeast winds will cause building waves into the southwest arm as well, and conditions may become hazardous for mariners at times today before winds diminish this evening. A Small Craft Advisory has been issued for much of the North Shore and the South Shore beginning at 10AM this morning. Gusts may approach 25 knots, causing waves to build to near 5 feet.
The next chance for showers and storms begins early Monday morning, through the day.
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 10 AM this morning to 8 PM CDT this evening for LSZ141>146-150. Dense Fog Advisory until 10 AM CDT this morning for LSZ144>146.
&&
$$
DISCUSSION...HA AVIATION...HA MARINE...HA
NWS DLH Office Area Forecast Discussion