textproduct: Marquette

KEY MESSAGES

- A system passing through Minnesota brings chances for light rain to mainly the western half of the UP today.

- Another system brings additional rain chances late Wednesday through early Thursday.

- Near normal temperatures today will be followed by a warm- up midweek.

DISCUSSION

Issued at 316 AM EDT Tue Oct 27 2026

Early morning RAP analysis and water vapor imagery shows a shortwave trough lifting through the eastern Dakotas, with an associated surface low located over NW Iowa. A weak warm advection regime and isentropic ascent ahead of these features is resulting in light rain showers spreading into the western and southcentral UP this morning, with temperatures mainly in the 30s across the area. Chances for light rain will persist through the day today, mainly across the western half of Upper Michigan as the surface low tracks northeast across Minnesota and grazes the western tip of Lake Superior this evening. Expect only minimal precipitation amounts of a tenth of an inch or less for most of the area today as the highest QPF values remain west of the UP, though a few spots in the west from the Porcupine Mountains to the Keweenaw could see slightly higher amounts approaching a quarter inch (30% chance per latest HREF). Breezy south-southeast winds will also develop today as the pressure gradient tightens between the approaching low and surface high pressure over northern Ontario, yielding widespread gusts to 20 mph across the UP and gusts as high as 30 mph for favored downslope areas near Lake Superior. Temperatures will be a bit warmer than yesterday across the area, with highs in the 50s for most locations.

Temperatures will spike well above normal on Wednesday as continued warm advection sends 850 mb temps to 10-12 C and allows surface temps to reach the upper 60s and perhaps even 70 degrees in a few locations Wednesday afternoon. However, the warm up will be short lived as another low forming in the lee of the Colorado Rockies tracks to northern Ontario and drags a cold front across the UP Wednesday night. This will bring another round of rain Wednesday evening through Thursday morning. Rainfall amounts do not look particularly impressive, but the NBM does depict a 50-75% chance for a wetting rain of a quarter inch over roughly the western third of the UP by Thursday morning. Those probabilities quickly drop off to 15-25% across the central and eastern UP. Modest instability on the order of a few hundred J/kg MUCAPE could also produce a few rumbles of thunder as the front passes through the area. Once precipitation clears the eastern UP Thursday morning, dry weather looks increasingly likely for the rest of THursday through Friday as high pressure builds back into the region from the northern Plains while temperatures moderate back down into the 50s for the end of the work week. Medium range guidance then hints at another system approaching the region with additional rain chances this weekend, but with a relatively high degree of spread at this time.

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 747 AM EDT Tue Oct 27 2026

A shortwave lifting through the Upper Midwest continues VFR/MVFR conditions and light rain for the western UP. The bulk of the rain will be seen at IWD with scattered showers impacting CMX. Cant rule out a few isolated showers at SAW but left out any mention in the TAF at this time. Ascent for scattered showers departs to the NW this afternoon after ~18z, returning dry conditions to all TAF sites, however a few isolated showers may linger at IWD. Additionally, gusty S to SW winds will be on the increase today reaching 15-25 kts by evening, greatest at SAW.

MARINE

Issued at 316 AM EDT Tue Oct 27 2026

Lake Superior: Southeast winds increase to 15-25 kt across the lake today as the surface gradient is squeezed between approaching low pressure over Minnesota and high pressure over northern Ontario. This will support small craft headlines across many of the nearshore zones into at least tonight. Can't completely rule out a few stray gusts to near gale force later this afternoon into this evening, but low probability and sparse coverage preclude consideration for any headlines. Winds gradually veer south-southwesterly and diminish below 20 kt through early Wednesday, but southerlies increase again Wednesday night as another low tracks into northern Ontario. Winds shift northwesterly behind a cold front on Thursday, gusting to 25- 30 kt over the eastern half of the lake with around a 25-40% chance for low end gales at this time. Winds diminish below 20 kt as high pressure builds over the region Thursday night into Friday.

Northern Lake Michigan and northern Bay of Green Bay: Southeast winds increase to 15-20 kt this afternoon as surface low pressure passes well to the west across Minnesota, gradually turning south- southwesterly tonight through Wednesday. Another low passing north of the area increases southerlies to 20-25 kt Wednesday night. Winds then shift northwesterly at 10-15 kt behind a passing cold front on Thursday, with lighter winds then expected as high pressure builds in for the end of the week.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... None. Lake Superior... None. Lake Michigan... None.