MADISON (WKOW) - A Freeze watch is in effect for the entire after Friday night into Saturday morning.
Cold air will spill in from the Arctic Circle. The jet stream, which are fast-moving winds in the upper-levels of the atmosphere, divide air masses.
The polar jet stream, aka the "polar vortex" will break off from the Arctic Circle and spill into the Great Lakes region before shifting towards New England.
This is highly unusual for this late in the season.
Today has been pleasant with mostly to partly sunny skies and highs in the low 60s. There has been a breeze out of the NW at 10-15 mph.
Temps tonight dip to the low and mid 30s under partly to mostly clear skies.
Patchy frost is possible, especially in rural communities, so plan on covering or bringing in your sensitive plants.
Temps will be significantly colder as the Arctic air moves in. Highs will only get to the mid 40s, about 20° below average for this time of year.
Friday night into Saturday morning will be even colder in the upper 20s!
Temps rebound to the mid 50s by Saturday afternoon with a good amount of sunshine.
Light rain develops Saturday night as a clipper system moves in from the Northern Plains.
Scattered rain will continue for Mother's Day and the added clouds will cause a cooler feel in the low 50s.