A 70-degree high Friday would be 2014’s fifth here; sharp weekend temp pullback ahead as east/northeast winds take hold and strengthen

By Meteorologist Tom Skilling

Chicago finds itself in a windy air mass of Pacific origin Friday.   Temperatures are headed for 70-degrees for the 5th time this year. That’s 4 more than had occurred by this date a year ago and surprisingly, in a year so dominated by temperature deficits, close to the long-term average number of 70-degree days by this date.

But enjoy the mild temperatures—a downturn looms once a front passes Friday night and shifts winds northeasterly. And, the development of a potent spring storm to our west is to set the stage for strengthening winds likely to gust over 30 mph as they ride into the city off chilly Lake Michigan.

The persistence of easterly winds into the first half of next week is likely to produce a wide spread in temperatures between lakeside and inland locations.

Large, slow-moving spring storm generating big computer model rainfall estimates 

The huge spread in barometric pressures between a sprawling Canadian high pressure to the north and a deep storm expected to trek only slowly out of the central Rockies and into downstate Illinois and Indiana by the middle of next week is not only to produce gusty winds but also to encourage moisture-rich Gulf air to ride into the cooler air predicted here. It’s a process expected to give rise to waves of rainfall—some thundery and capable of downpours—which may really add up between Sunday and later next week.

Model forecasts suggest rains across that span of time could be as much as three times the 0.83” which typically falls over a 7 day period this time of the year—with totals potentially ending up in the 2 to 3″ range—possibly even higher  in some locations.

Chicago spring rainfall of 3.04” the driest to date in 9 years and 20th driest on record

Rainfall of that magnitude would reverse the “drier than normal” precipitation trend which has dominated meteorological spring here.

At present, 3.04” is on the books—just 59% of the normal 5.16” to date. The tally is the lowest of any spring here in 9 years and 7.54” behind the season’s total rainfall by this date a year ago. The 3.04″ total to-date ranks 20th-driest of the past 143 springs.

ASKT TOM: Shortest distance between U.S. temperature extremes

Dear Tom,

The nation’s extreme temperatures Monday were both recorded in California at locations separated by only about 250 miles. What is the closest distance between extremes ever recorded?

–Thomas Rocheleau, Gurnee

Dear Thomas,

Temperature observation stations at Truckee and Death Valley (the locations in question), both in California and separated by 254 miles, register same-day extremes a few days every year. That was the case Monday on April 21. We searched the lists of national daily temperature extremes back to 1997 and found that on Sept. 11, 2013, Medford and Silver Lake, both in Oregon, recorded the national temperature extremes on that day. Separated by only 135 miles, those cities might very well have be the shortest “as-the-crow-flies” distance.

Weather snapshots

Photographer John Kleeman is getting a wave from Lanny Gray whose out in the field sowing oats with the assist of his trust 1956 John Deere tractor.  He's working the field here between Route 83---Lake/Cook Road and Buffalo Grove Road in our near northwest suburbs. Photo courtesy of John Kleeman, Buffalo Grove, IL

Photographer John Kleeman is getting a wave from Lanny Gray whose out in the field sowing oats with the assist of his trust 1956 John Deere tractor. He’s working the field here between Route 83—Lake/Cook Road and Buffalo Grove Road in our near northwest suburbs. Photo courtesy of John Kleeman, Buffalo Grove, IL

A closer look at Lanny Gray looking over his tractor. Photographer John  Kleeman says its a ritual of spring and one in which our local farmers and gardeners engage in each year--and a sign spring planting is getting underway. Photo courtesy of John Kleeman, Buffalo Grove, IL

A closer look at Lanny Gray looking over his tractor. Photographer John Kleeman says its a ritual of spring and one in which our local farmers and gardeners engage in each year–and a sign spring planting is getting underway.
Photo courtesy of John Kleeman, Buffalo Grove, IL

Jeffrey Katz, camera in hand at Beverly Shores Indiana Dunes, captures the Chicago skyline catching the first rays of the rising sun, in this tremendous photo.Photo courtesy of Jeffrey Katz, Beverly Shores Indiana Dunes

Jeffrey Katz, camera in hand at Beverly Shores Indiana Dunes, captures the Chicago skyline catching the first rays of the rising sun, in this tremendous photo.Photo courtesy of Jeffrey Katz, Beverly Shores Indiana Dunes

At the other end of the day, Dan Kuiper sends us this eye-catching sunset with its spectacular orange and red hues taken from the Indiana Dunes.  Dan says he's put this gorgeous shot to work as the screensaver photo on his computer--and NO WONDER!  It's quite a shot, Dan---THANK YOU! Photo courtesy of Dan Kuiper, From Indiana Dunes

At the other end of the day, Dan Kuiper sends us this eye-catching sunset with its spectacular orange and red hues taken from the Indiana Dunes. Dan says he’s put this gorgeous shot to work as the screensaver photo on his computer–and NO WONDER! It’s quite a shot, Dan—THANK YOU!
Photo courtesy of Dan Kuiper, From Indiana Dunes

This majestic fella is a Swallow soaking up the Easter Sunday rays in this photograph which comes to us from William Vermette.  William took this at Wolf Road Prairie in Westchester. Photo courtesy of William Vermette, Wolf Prairie Road-Westchester

This majestic fella is a Swallow soaking up the Easter Sunday rays in this photograph which comes to us from William Vermette. William took this at Wolf Road Prairie in Westchester. Photo courtesy of William Vermette, Wolf Prairie Road-Westchester

And this gorgeous sunset this past Tuesday evening comes to us from Lynn Xydas in Palatine.  Such beautiful sunsets of late! THANKS Lynn! Photo courtesy of Lynn Xydas, Palatine, IL

And this gorgeous sunset this past Tuesday evening comes to us from Lynn Xydas in Palatine. Such beautiful sunsets of late! THANKS Lynn! Photo courtesy of Lynn Xydas, Palatine, IL

Scattered showers and a few thunderstorms possible this evening and overnight

Showers and a few embedded thunderstorms will precede and accompany a center of low pressure as it tracks east out of Missouri through central Illinois tonight on into Indiana early Friday. In the Chicago area, showers and possibly a few thunderstorms should spread into the area from the west late this afternoon/early evening and continue as the center of low pressure passes just to our south overnight.

Rainfall amounts should generally be a half-inch or less, although greater amounts under stronger thunderstorm downpours may occur. Strong southeast winds gusting over 30 miles per hour will continue in our area this evening – then swing more east to eventually northeast as the center of low pressure tracks east through central Illinois tonight.

By sunrise Friday, rain should be over in the Chicago area with the center of low pressure in central Indiana pulling away to the east. Winds Friday morning will be northwest 15 to 25 miles per hour here – gradually becoming more westerly as the day progresses.

Cubs fans celebrate Wrigley Field’s 100th birthday in a late March-level chill; northeast winds establish a large temp spread across the area

By Meteorologist Tom Skilling

It was SO nippy Wednesday that the day’s chilly northeast flow off Lake Michigan could only muster a March-level high of 51-degrees.

The flow produced quite a range ion temperatures across the greater Chicago area Wednesday. While inland readings hit 60 degrees toward Pontiac, lakeside temperatures made it no higher than 42 degrees at a number of locations.

Temps are to surge most strongly away from the lake Thursday; highs likely to beat Wednesday’s by almost 20-degrees inland.

Readings will rebound Thursday and Friday reaching the mid-60s inland Thursday and close to 70 degrees over much of the area Friday—-a near 20-degree increase compared to Wednesday’s highs.

Powerful spring storm’s southerly front side winds are to help pump temperatures up during this period. But model forecasts take readings down dramatically this weekend as rain chances edge higher Sunday—and even more so Sunday night and Monday.