ROCKFORD (WREX) — Friday morning is off to a frosty start, as lows dive below freezing for the first time since May.
Hello, sub-freezing temperatures:
A well-advertised freeze is underway early Friday morning, as temperatures drop to and below 32°. A freeze warning remains in effect until 9 a.m. Friday, advertising the potential of crop-killing freezing temperatures. The cold start is a sign of the cool air that sits on top of the Upper Midwest late in the work week.
Highs Friday afternoon climb into the lower to middle 50s under a mix of sun and clouds. A quick-moving disturbance could provide a few spotty showers late in the morning into the afternoon. If precipitation can start early enough, a flake or two of snow is possible. If flakes fly, it is going to be a novelty and not so much a nuisance thanks to still-warm surface temperatures. Scattered showers later in the day could contain graupel, or "soft hail" thanks to very low freezing levels in the atmosphere.
Any shower activity that develops across the Stateline Friday afternoon should wrap up by early in the evening. Clouds do move in by early Saturday morning, keeping lows slightly "warmer," generally in the middle 30s.
Weekend of change:
Saturday does feature more clouds than sunshine, but the weather headline to pay attention to is the wind! As pressure falls out ahead of an approaching cold front, winds respond in a gusty way. Southwesterly winds, while pulling in warmer temperatures, could gust to 45 or 50 miles per hour.
For areas along and south of I-80, a fire weather watch goes into effect Saturday. Locally, nothing like that goes into effect, but outdoor burning is still off-limits Saturday afternoon thanks to the wind.
An isolated shower is possible during the second half of the day Saturday as temperatures climb into the middle 60s. Better chances for precipitation come in overnight Saturday into Sunday morning.
Cold front means business:
The cold front that comes marching through the Stateline late Saturday night means business. Temperatures Sunday afternoon struggle to make it out of the 40s under mostly cloudy and breezy conditions.
Kicking off Sunday morning could be an interesting one! Some models hint at that four letter "S-word" that people either love or love to hate. The cold frontal passage is going to bring a narrow band of light precipitation, but the issue is whether or not the air is cold enough.
Cold air tends to move pretty sluggishly, so does the cold air catch up to precipitation before it exits? That remains the million dollar question that should become more clear over the next 24 to 48 hours.
Briefly cooler next week:
The potent cold front moves through Sunday, allowing temperatures to come tumbling. Lows overnight Sunday into Monday morning could again drop into the upper 20s and lower 30s. Freeze warnings might not be needed if Friday morning marks the end of the growing season.
High temperatures to kick off the next work week only top out in the upper 40s, which is well below average for mid-to-late-October.