Marine Weather and Tide Forecast for Altoona, WI

DISCUSSION
Issued at 228 PM CDT Fri May 16 2025

A remarkably deep surface low (earlier as low as 980 mb) is tracking across central Minnesota this afternoon. Steady wind- driven light rain to the south of the low will continue to overspread the entire forecast area through the remainder of the afternoon and evening then gradually taper off overnight.
Precipitation amounts will be light, generally less than a few tenths of an inch at most. Gusty winds will decrease a bit but still gust as high as 30-40 mph at times this afternoon and again overnight as winds switch to northwesterly following the passage of the low to the north.

Saturday will be dry precip-wise but steady cyclonic low-level flow/cold air advection through the day will keep persistent cloud cover in place and will also keep temperatures confined to the lower/middle 50s through the day, and parts of central MN may not make it out of the upper 40s. Clouds will scatter out a bit on Sunday allowing temperatures to rise into the upper 50s and lower/middle 60s.

The next system of interest will track into the Central Plains/Midwest early next week with a surface low tracking across northern MO/southern IA. This track will keep any threat for strong storms well to the south of the area, and a recent southerly trend of this track may mean precip struggles to make it any further north than the I-94 corridor. Should this system trend a bit northward it could bring some beneficial rains of 1" to 2" into southern MN, but for now this seems more likely to occur across Iowa. Ridging behind this system will finally bring temperatures back to near normal (low 70s) by Thursday and Friday.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
Issued at 703 PM CDT Fri May 16 2025

As the surface low wobbles down into central MN, we've started to see the winds relax, with directions veering toward the northwest with time. We'll remain in moist cyclonic flow through Saturday, which means the clouds will remain in place through then as well. Models are aggressive with dropping cigs into the IFR level tonight and we should get there tonight, but did delay their arrival with this update. Otherwise, TAFs look to be in good shape, with winds becoming northwest overnight and remaining there through the day on Saturday with gusts still going at around 25 kts.

KMSP...Rain will continue for about the first three hours, with more intermittent showers continuing through 10z. LAV still drops cigs down to 007 overnight, but upstream obs haven't really supported the widespread IFR cigs like the LAV has, so started to trend cig heights up a bit for the overnight hours.
As for when we'll shake the clouds, 21z RAP soundings show these clouds sticking around until around noon on Sunday.

/OUTLOOK FOR KMSP/ SUN...VFR. Wind NE 5-10 kts.
MON...Mainly VFR. Chance MVFR/SHRA. Wind E 15-20G30kts.
TUE...Mainly VFR. Chance MVFR/SHRA. Wind E 15-20G30kts.

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