Marine Weather and Tide Forecast for Rochester, MN

DISCUSSION
Issued at 312 AM CDT Wed Jul 22 2026

Through Friday: Below Average Temperatures and Dry Conditions

Upper level high pressure is forecast to remain over the Southern Plains with the main ridge axis oriented northwest towards the Pacific Northwest. Troughing should persist over the eastern Great Lakes leading to northwest flow over the Northern Plains into the Midwest. This pattern will continue to favor dry conditions along with slightly below average temperatures the rest of the work week. High temperatures will slowly climb back into the lower 80s by Friday as upper level heights increase over the Southern Plains into the Intermountain West.

This Weekend into Next Week: Summer Heat Returns along with Thunderstorm Chances

The strong high pressure system over the south central US should solidly remain in place this weekend into early next week. Moisture throughout the column will surge northward towards the Upper Mississippi River Valley which should result in the return of thunderstorm chances. A subtle shortwave may lead to some rain chances on Saturday night into Sunday morning, but confidence in that scenario is not high at this time with blended model guidance depicting only a 10-20 percent chance at rain this far out. There is higher confidence in the rain potential on Sunday afternoon into the evening as a stronger shortwave and secondary moisture plume move over the region. Sufficient instability may be in place to support a severe storm threat on either Saturday or Sunday, however, low level capping could be an issue due to the ridge.

The combination of higher moisture and hot temperatures may result in heat index values approaching 100 degrees across portions of the western and southern CWA on Sunday. The latest long range ensembles are certainly hinting at this potential with a 30-40 percent chance at reaching the 100 degree heat index value on Sunday, which is currently expected to be the hottest day of this forecast period.
Just how hot it could get on Sunday will be highly dependent upon cloud cover and the potential precipitation chances throughout the day.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
Issued at 548 AM CDT Wed Jul 22 2026

VFR expected through much of the 22.12Z TAF period. Valley fog is possible primarily within the Wisconsin (KOVS) River and potentially Mississippi River for Thursday morning. Lower confidence in short term model solutions at the current forecast hour nearing the terminus of current TAF period omits inclusion in KLSE TAF.

ARX WATCHES/WARNINGS/ADVISORIES
WI...None.
MN...None.
IA...None.