Marine Weather and Tide Forecast for Nelson, WI

DISCUSSION
Issued at 253 AM CDT Sat Apr 18 2026

Surface analysis this early this morning shows a potent 996mb low over Lake Superior with a trailing cold front sagging southwest over WI/IL/MO. Expansive high pressure sits over the Rockies, extending as far east as the Mississippi River and as far west as the Pacific shoreline. Aloft, a wound-up 516dam low sites over the Manitoba/Ontario border, with a trough axis extending south over the North-Central Plains. A highly amplified ridge is moving onshore the Pacific Coast, helping nudge the trough eastward, albeit slowly.

The cold front will continue to press east through the day while surface high pressure moves in from the west. While this will result in gradual clearing (aside from passing high clouds)
going through the daylight hours, the area of high pressure over the Rockies will also spill over into the Plains, making for a tightened pressure gradient into the Upper Midwest. This combination of features will make for breezy and dry conditions, potentially near-critical fire weather conditions, through the day today but also continued cold conditions for mid-April.
While normal highs are in the mid 50s, highs today will only reach the mid 40s. The lack of airmass change between today and tomorrow will mean that temperatures will have very little change for Sunday, mainly in the mid 40s but temperatures near and southwest of the Minnesota River may creep into the upper 40s for highs. Meanwhile, lows both this morning and early Sunday morning will drop below freezing, potentially as low as the mid 20s.

The only chance of precipitation through at least the middle of next week will come late tonight to early Sunday morning as a weak trough axis rounds the western fringes of the departing aforementioned surface low and under the deep upper level low.
This trough will coincide its movement over the Upper Midwest with a slightly deeper swath of H7-H5 moisture. Given the sub- freezing depth in the atmosphere at the time it looks to move across the WFO MPX coverage area, there may be a few snow showers moving across our area. No accumulations are expected with much warmer ground temperatures and green-up occurring.

Dry and warmer weather is expected through the first half of the upcoming week as the western ridge expands east into the north- central CONUS with high pressure dominating our region of the lower 48. Even with a frontal boundary looking to push through the region on Tuesday, its only impact will be an increase in cloud cover as the depth of atmospheric moisture will be rather lacking and upper level forcing will be moot with incoming ridging. Otherwise, the notable feature will be a return to above normal temperatures for the workweek. Highs will return to the 70s and 80s through Thursday, which is when the next widespread notable rain-maker is expected for our area. That system will move across the Upper Midwest Thursday night through Friday morning, followed by another appreciable cool- down for next weekend.

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
Issued at 545 AM CDT Sat Apr 18 2026

Main aviation concern for the 12z TAF period will be the persistence of breezy northwesterly flow across all terminals.
Sustained winds between 15-20kts with gusts between 25-30kts will be common throughout the day, though there will be little if any change in the prevailing direction. Winds will relax this evening. Otherwise, quiet with low VFR stratus between 3-4k feet set to mix out early in the period. A quick moving disturbance will bring the chance for a few raindrops/snowflakes late tonight into early Sunday. No mention was made in the TAFs as this precipitation will result in little impact.

KMSP...Breezy WNW winds prevail through the period. Strongest gusts will approach 30kts before diminishing this evening.

/OUTLOOK FOR KMSP/ MON...VFR. Wind SE 10kts becoming S 10G20kts.
TUE...VFR. Wind SW 5-10kts becoming N.
WED...VFR. Wind SE 5-10kts.

MPX WATCHES/WARNINGS/ADVISORIES
MN...None.
WI...None.