Regional weather view.
Attention is on a very chilly airmass settling into the Upper Midwest which came in on a cold front that slid through Tuesday. It will feel very like fall across the entire region, some places may not even get out of the 50s on Wednesday in Minnesota and Wisconsin. A early widespread freeze or frost is likely across South Dakota, Minnesota, Most of Wisconsin and Iowa..
Local View.
Locally we can expect very chilly conditions as we get into Wednesday. It will feel fall like, and will feel chilly to even “coldish” Under chilly but sunny conditions. Highs will not even get out of the 50s. This will set the stage for the areas 1st frost and possibly freeze of the season, which is discussed below. The cool, sunny conditions will last through Thursday with highs a bit warmer in the low 60s, and lows near frosting potential again in the upper 30s to 40.F on Thursday Night.
Widespread Wednesday Night hard Frost/Freeze likely.
Wednesday after highs are reached, clear skies and light winds overnight will allow for significantly dropping temperatures after sunset, lows will fall to the low to mid 30s across many areas. This will likely cause widespread killing frost for much of the area. it now looks to end the growing season for some parts of Southeast Minnesota as some places may reach the upper 20s, The best chance for this and a freeze will be north of Rochester and Winona. South of there are hard frost is still likely with lows in the mid 30s. This is very early for frosts this hard in Southern Minnesota. Temperatures in the upper 20s to low 30s this early will kill tender annuals and veggies, and can cause damage to landscape trees and shrubs. People should take time to bring in tender annuals or veggies, as well as over summering houseplants Wednesday Night, and keep them in Thursday Night as well lows once again will dip to the once again into the mid to upper 30s
Metro view.
For the Rochester Metro, we can also expect Wednesday to be our coldest day, it will be very chilly even with sunshine. Highs may briefly reach 60, then after sunset temps will quickly fall off dipping into the 30s. Thursday will bring slightly warmer conditions with highs in the mid 60s, and lows in the low 40s.
Rochester Frost Chances.
Frost is also a likelyhood for the Rochester Metro, the worst frost or growing season ending freeze with low 30s will be in outlying residential areas such as around the airport and surrounding communities. I still feel the Inner residential and Downtown areas will likely see lighter patchy frosts with lows in the middle 30s. In these areas garden plants may be less damaged.
Wednesday, Very Chilly! Lots of sunshine with highs in the upper 50s to near 60. Wednesday Night, Clear Skies, Cold! Widespread frost or freeze likely. lows falling to the low to middle 30s. with upper 20s possible in cooler spots north.
Thursday, Chilly, Sunny with highs in the low to mid 60s. Thursday Night, Very Chilly, Clear skies with lows in the mid to upper 30s.
Looking Ahead
After this nosedive in temps, it stabilizes into the first part of the weekend with more milder and dry conditions. The models are trying to hint and a slightly wetter pattern trying to set up for the second half of next weekend. Then it dries out with fair temps for Monday and Tuesday the 19th and 20th. The models then show a much warmer, but dry air mass pulling into the region around the 23rd. Then a very cold low pressure system passes Northeast around the 29th, not looking to effect our weather at this time.