Marquette, Michigan

• A few light showers are possible this evening (20-40% chance). Those headed out trick-or-treating may want to have an umbrella handy, particularly in the far western U.P. and close to the WI/MI border.
• Temperatures will be unseasonably warm Sunday through Tuesday with highs/lows 15-25F warmer than seasonal averages.
• Periods of widespread rain are expected Monday afternoon through Tuesday evening. There is a 60-80% chance for over 1" of rainfall over a 48 hour period, highest in the southern and western U.P.
• Forecast confidence is low for precipitation chances Wednesday through Friday as some model solutions are slower with the progression of the system this week, which could result in additional rainfall for the mid to late week.

This afternoon GOES satellite imagery and GFS 500mb height analysis showed upper level ridging over the central U.S ahead of an upstream trough along the West Coast. Clouds were widespread from the Gulf coast north through the Plains and Midwest as warm, moist are was spreading northwards. A weak shortwave on the western edge of the ridge and area of isentropic ascent was kicking of scattered showers across the eastern portion of Minnesota and northern WI. Clouds were starting to spread over the southern half of the U.P. but were taking their time, working against dry air in place. Surface observations showed light southerly winds across the U.P. with temperatures in the upper 40s to lower 50s. Temperatures should continue to climb into the mid 50s as the afternoon progresses.

Tonight the shortwave and associated warm front will lift north through the U.P. bringing widespread cloud cover and a period of scattered showers. Clouds and increasing low level moisture will help keep temperatures warmer tonight, generally in the 40s. While most of the showers are expected later this evening, areas in the western U.P. and near the WI/MI border could see scattered showers earlier in the evening. Showers are expected to remain on the lighter side, with only a few hundreths of an inch of rainfall.

Unseasonably warm temperatures can be expected for Sunday into early next week along with widespread cloud cover. Sunday should be mostly dry but deep saturation in sounding profiles favor the potential for a few sprinkles. Expect highs in the low to mid 60s through Tuesday and lows in the upper 40s to 50s (15-25F above average for early November).

Along with the warmer and more humid conditions, periods of widespread rainfall are expected Monday night into Tuesday night. The first period is expected to overspread the U.P. from west to east Monday late afternoon into the evening hours as low pressure lifts north from Colorado and tracks towards Minnesota. This bring strengthening isentropic ascent / waa resulting in moderate to potentially heavy rainfall at times. Additional rounds of showers can be expected on Tuesday into Tuesday night with the area remaining in the warm sector of the system as the low tracks north into Ontario and stalls/retrogrades as it phases with a clipper like system. Couldn`t completely rule out thunder at times as LIs approach 0 to -1 and mucape reaches 200-500 J/kg.

There will be an elevated risk for excessive rainfall Monday night into Tuesday; WPC highlights a marginal (5%) risk. ECMWF EFIs are relatively high over much of the U.P. with a SOT of 1 over the south and west for QPF Monday night through Tuesday afternoon. NBM probabilities for 1" or more of rainfall through the event are around 80% in the south and west and 60% in the east. The probability for 2" or more is around 30% in the south and west but the higher probabilities lie west of the area over central MN, closer to the track of the low pressure.

Winds turn westerly Wednesday behind a cold front that sweeps across the U.P. on Wednesday night, with a shift to the north by Thursday. This will bring cooler air back into the area with highs in the upper 40s to low 50s, closer to but still several degrees above seasonal averages. Shower chances continue Wednesday through Friday but generally in the 20-30% range at this time. Models diverge on how they handle the merging of the low Colorado and clipper-like lows with the ECMWF much slower (and wetter) with the system. Cluster analysis (GEFS, ECS and CMC) have about 23% of the members favoring the deterministic ECMWF solution while the remaining members fairly evenly spread across solutions favoring either a more northerly track and/or faster (drier) solutions. Thus quite a bit of uncertainty remains at this point.

VFR conditions will continue across the UP this evening; however a disturbance will move through this evening, and will lower ceilings down to MVFR early this evening and down to IFR overnight. After sunrise tomorrow, condition will improve to back to MVFR. Southerly winds less than 10 kts are expected for the forecast period.

Light southerly winds of 20 kts or less continue through early next week as high pressure ridging largely dominates. Monday night into Tuesday low pressure will track north from Colorado to MN with an associated warm front lifting across the region. Southerly winds will increase up to 30kt over the eastern part of Lake Superior and 20-25kt over Northern Lake Michigan. For the western half of Lake Superior winds will be around 20kt. Winds shift westerly 15-20kt behind a cold front Tuesday night (stronger 20-25kt over the eastern part of Lake Superior) and eventually turn northerly on Thursday. Warm, moist air and widespread rainfall could result in dense fog Monday night into Tuesday.

Upper Michigan

None.

Lake Superior

None.

Lake Michigan

None.