Warmth has been in short supply in 2014. It’s a fact which has led to excitement over a potential for a 60-degree Friday daytime high.
Not since the 69-degree peak reading in the area on Nov. 17 has the Chicago area been treated to such a level of warmth.
Weather records indicate an average of three 60s have often occurred here by March 21, underscoring the sluggishness of seasonal warming to date.
The warmth won’t be present right away. In fact, the southeast winds predicted into the early afternoon in lakeshore areas are likely to maintain a level a chill well below 60-degrees, and nowhere more so than along Lake Michigan. But a northbound warm front is to make its way into the area, likely reaching all but the northernmost lakeshore communities in northeast Illinois. In these areas, 40s could stand their ground Friday, even as 60-degree readings advance into much of the Chicago area to the south and southwest.
The pool of mild air which Friday’s southwest winds are to tap, produced 60-degree and warmer temperatures over all but 19 of the Lower 48 states Thursday. Unfortunately, unseasonable warmth aloft over western North America into Alaska is to produce the latest northward buckle in the jet stream over coming days which sets the stage for the powerful northwesterly steering winds which will ride down the eastern flank of this upper reservoir of mild air into the Midwest. This is a formula for transporting late season arctic air back into the region. Temperatures will be downtrending as a result in the days ahead.
Colder air’s arrival to provoke late Friday/Friday evening shower development
Models suggest the beginning of this cooling process, expected to follow a cold frontal passage into the Chicago area beginning Friday evening, may initiate shower development. It’s not out of the question a thunderstorm may develop in a few locations before the predicted Friday night temp downturn begins.
Cooling over the weekend is to come in stages—with daytime readings dipping into the low 40s Saturday and to the low or mid 30s Sunday.
Thursday’s 0.7″ snow brings official snow tally to 80″—just 9.7″ short of the record
The burst of snowfall which swept portions of the Chicago area Thursday morning generated a short-lived 0.7” accumulation at O’Hare. It was enough snow to push the city’s official 2013-14 seasonal snow total to 80”. That’s just 9.7” shy of the city’s official seasonal snow record of 89.7” in 1978-79.
99 of 129 years have recorded measurable snow beyond March 21; 14 of them have generated 6″+ snows
That reaching or exceeding the snow record may still be within reach is underscored by official weather records here.
99 of the 129 years for which we have snow records—-77% of them—have produced measurable snow beyond March 21. And 14 of these years have generated significant snowfalls in excess of 6”.
Monday night/Tuesday snow chances continue, making it a system to monitor; conditions could be favorable for some lake enhancement Tuesday
The snow threat which could next produce an accumulation here would take place in the Monday night/Tuesday time frame. Early temperature and wind profiles don’t rule out the possibility lake-enhanced snowfall could be part of that snowy period. We’ll keep you posted.