Driftless Week: Cool Showers, Morning Fog, Then a Midweek Reprieve

October 30, 2025

A compact meteorological story this week: today we sit in a weak ridge between two upper lows — one over the lower Ohio Valley and another swinging down from the Canadian Prairies. That positioning keeps most of the ARX region dry through the day with near-normal temperatures in the low–mid 50s, but the Canadian shortwave will begin to nudge in late afternoon and could spark a few very light showers across southeast Minnesota and northeast Iowa. Think brief drizzle or a few hundredths of an inch at most — nothing to cancel a midday hike, but enough to make wet leaves and slick rocks grabbier than they look.

Friday into Saturday the Canadian upper low drops into the Upper Mississippi Valley and nearly cuts off. In plain terms: the atmosphere becomes a little more stagnant, mid-level moisture hangs around, and while surface forcing is weak you still get periodic, scattered chances for light showers. Models and HREF clusters show low QPF — the rain will be spotty and mostly light — but forecasters nudged PoPs up slightly from previous guidance because even when totals are tiny that’s when trails go slick. Temperatures respond to northerly flow; highs fall into the mid-to-upper 40s and nights drop to the low-to-mid 30s. The profile is cold enough in places (especially in southeast Minnesota and parts of north-central Wisconsin) that a few flakes could mix with showers — a few snow grains at best, no buildup expected.

Sunday and into early next week the trough slides east and upper-level flow becomes more zonal. Return flow increases moisture surging in from the southwest overnight Sunday into Monday, but most of the sensible weather trend is toward drier, warmer conditions. A rebuilding ridge to the west shifts temperatures upward: expect pleasant afternoons Monday–Wednesday with highs touching the upper 50s into around 60 by midweek. Winds can gust briefly — models show gusts into the 20s Monday — so plan camp setups and small-boat outings around that.

Practical translation for adventurers:

• Morning river valleys and tributary lowlands (Mississippi corridor, side creeks) can produce dense valley fog and low stratus. Visibility reductions to a quarter mile are possible into mid-morning; expect MVFR/brief IFR conditions at local fields early. If you’re launching a canoe or kayak at sunrise, be prepared for very limited visibility and err on the side of leaving later.
• Late-afternoon light showers are possible today in southeast MN/northeast IA; Friday–Saturday bring the best chance for scattered light showers across the region. Most precipitation amounts are under a tenth of an inch. This means wet trails, slippery roots, and damp gear more than soggy, rain-soaked days.
• Cold pockets and a shallow cold layer near the surface Friday–Saturday could allow a few snow flakes to mix in for northern bluff country and higher terrain. This is a curiosity for photographers, not a concern for winter sports. No accumulation expected.
• Sunday through midweek looks like the best window for longer adventures. Drier air, milder afternoons, and clearer skies make extended hikes, road/gravel rides, and paddling (when winds are light) attractive. That said, afternoons can be gusty Monday; secure tents and be cautious on exposed ridge lines and on large rivers.

How to plan your outing:

• Short, local hikes, trail runs, and technical singletrack on Thursday are workable if you time them midday — mornings will be foggy and late afternoons could see a stray shower.
• Friday and Saturday, treat trails as wet: use footwear with good grip, expect colder air, and layer warm, water-resistant outerwear. Avoid long river crossings if you can, and keep river put-ins for later in the day when fog has burned off.
• Reserve the longer big-day adventures (multi-hour hikes, long bike loops, full-day paddles) for Sunday–Wednesday when the pattern trends more reliably dry and comfortable.

Risks to keep front of mind: morning fog and low ceilings that reduce visibility on roads and rivers; slick leaves and wet rock on trails during the light shower periods; cold overnight temperatures that make an unexpected night out more dangerous; and gusty winds Monday that can complicate tent camping and make river conditions choppy.

Bottom line: this is an autumn transition week — a few damp, cool days followed by a warmer, drier midweek window. Be flexible with start times, carry a light waterproof layer, and choose the quieter, lower-risk adventures early in the week while saving the long outings for the sunnier midweek stretch.