I.) Frost On The Pumpkin: Skies will clear tonight and winds will go calm. Chilly high pressure will briefly build over the eastern Ohio Valley and lead to a calmer period of weather overnight into early Thursday morning. The end result will be the first widespread frost of the season across central Indiana, including many dipping into the lower-to-middle 30s.
II. Gusty Thursday: After a cold, calm start to our Thursday, southerly winds will become gusty late in the afternoon. This is a result of an approaching cold front that will impact the region Friday.
III. Unseasonably Cold Weekend: A cold front will pass Friday afternoon and a band of showers will accompany the frontal passage. Winds will shift to the northwest late in the day and drive in a sharply colder close to the work week. Air will grow cold enough to potentially support snow to mix in with the rain as precipitation comes to an end. Additionally, upper level energy and the colder air mass this weekend (the air will have a bite to it) could support mixed rain and snow showers Sunday. – Novelty stuff only, but those first flakes are always special to see. Nonetheless, temperatures will run well below normal. In fact, highs will be closer to our average low temperature this weekend.
IV: Reinforcing Halloween Chill: We still stand firm on the idea of warm costumes being required this Halloween as chilly reinforcements blow into town Monday night. This will result in Halloween featuring a high in the mid to upper 40s with lows Tuesday night/ Wednesday morning dipping to around freezing (upper 20s in outlying areas away from the metro). Most of Trick-or-treat hours should feature temperatures in the upper 30s and lower 40s.