Marine Weather and Tide Forecast for Dennison, MN

DISCUSSION
Issued at 205 PM CDT Thu Apr 30 2026

The broad upper low continues to spin over the Great Lakes region, keeping Minnesota and western Wisconsin within the same northwest flow pattern we've had the past couple of days. A number of weak waves embedded within the flow will provide us with several chances for light rain through at least early next week.

Our first chance is ongoing across the eastern Dakotas and far western Minnesota already this afternoon. Scattered showers tied to a weak boundary will slide southeast through southwestern Minnesota into Iowa, primarily impacting the MN River Valley.
Forecast soundings hint that this morning's pockets of sunshine will allow for some instability to develop, increasing the chance for a few rumbles of thunder this afternoon and evening where those showers move through.

Persistent CAA continues behind this weak wave tonight, prompting another round of frost and freeze headlines. We kept the northern extent of the headline the same as last night for continuity, though areas north of an advisory/warning can assume similar impacts for any vegetation that may be susceptible already. Cloud cover continues to remain tricky, though confidence is increasing for much of Minnesota to see mostly cloudy skies. This should limit any frost/freeze potential for this area specifically. Western Wisconsin should see less cloud cover, at least to start the night, giving us higher confidence for temperatures to approach or drop below 32F, especially in rural and low-lying areas.

The forecast is rinse and repeat for tomorrow night, though cloud cover will be a lot thinner, likely prompting more widespread frost/freeze headlines for areas that have susceptible vegetation. Any additional scattered showers during the day will be limited to southeast Minnesota and west-central Wisconsin.

This weekend, a milder airmass will settle in ahead of another approaching upper low, giving us a brief period of highs in the 60s. A series of cold fronts quickly follow, resulting in minor rain chances Saturday night and Monday morning. Behind the front on Monday, temperatures will dip back down into the 40s and 50s for a few days, and periodic rain chances return, similar to our pattern this week.

AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
Issued at 625 PM CDT Thu Apr 30 2026

VFR conditions will continue to persist through the period.
Expansive deck of bkn strato-cu will tend to become more scattered over most terminals this evening, though cloud coverage likely remains a bit higher across southwestern MN.
Tracking a few isolated rain showers across western MN with additional raindrops possible at RWF early in the period.
Northwesterly winds diminish this evening and will be light overnight, prior to increasing to roughly 10kts tomorrow afternoon. Another expansive strato-cu field with bases around 5-8k feet will develop tomorrow afternoon.

KMSP...No additional concerns.

/OUTLOOK FOR KMSP/ SAT...VFR. Wind SW 5-10 kts.
SUN...VFR. Wind NW 5-10 kts.
MON...VFR. Wind NW 10-15G30kts.

MPX WATCHES/WARNINGS/ADVISORIES
MN...Frost Advisory from midnight tonight to 8 AM CDT Friday for Anoka-Chippewa-Dakota-Goodhue-Isanti-Kandiyohi-Lac Qui Parle-McLeod-Meeker-Redwood-Renville-Sherburne-Washington- Wright-Yellow Medicine.
Freeze Warning from midnight tonight to 8 AM CDT Friday for Chisago.
WI...Frost Advisory from midnight tonight to 8 AM CDT Friday for Pepin-Pierce.
Freeze Warning from midnight tonight to 8 AM CDT Friday for Barron-Chippewa-Dunn-Eau Claire-Polk-Rusk-St. Croix.