By Meteorologist Tom Skilling
Get those extra blankets, jackets and sweaters ready! There's a formidable early season mass of cool air on the way which may produce frost patches in far northwest and west suburban locations in coming nights.
Chicago's earliest occurring 60-degree or lower daytime high in 15 years appears a real possibility Thursday as a huge Canadian high, extending 2,500 miles from north to south and 1,600 miles from west to east, settles southward into the Lower 48. Its central pressure is to be an impressive 1030 mb (30.42") when it arrives in North Dakota from Saskatchewan Wednesday evening.
The predicted Thursday high of 60-degrees at O'Hare would be 15-degrees below normal and more typical of a late October daytime reading than one in mid-September.
Chilly as a 60-degree high on Sept 15 would be, it's not a record---though it's not far from it. The record low max on the books here for Sept. 15 is 55-degrees set in 1993.
Freeze advisories posted for sections of 5 states
Sections of 5 states, from the Dakotas to Minnesota and northern Iowa, have been placed under freeze watches and warnings as the fresh batch of chilly air approaches. Though temperatures will be marginal for frost in Chicago's far west and northwest suburbs, mid 30-degree thermometer level temperatures, such as those predicted toward McHenry, Ogle, Lee, DeKalb, Boone and Winnebago counties, may well be cold enough to support a thin layer of freezing temperatures near the ground. In that environment some light patches of frost may form.
An official 32-degree or lower temperature last occurred at O'Hare April 21 and prospects a chill of that magnitude might occur in the city proper during the upcoming cool surge appears very low.
First 60-degree high last year arrived 10 days later; only one in ten years has seen highs this cool so early
Temperatures as cool or cooler than the 60-predicted Thursday at O'Hare didn't occur until Oct. 1-2 last year. That puts chill of this magnitude into the area nearly 2 weeks ahead of 2010.
In the past half century of observations at the O'Hare site, only one in 10 years has produced a 60-degree or lower high temperature by Sept. 15.
The Pagami Creek wildfire, responsible for Chicago's acrid shroud of smoke Tuesday, grows to 100,000 acres, triple its Sunday size
The eye-catching, orange-colored shroud of acrid-smelling smoke which settled over the Chicago area Tuesday afternoon originated in northeast Minnesota. Known as the Pagami Creek Wildfire, the blaze began with a lightning strike in the Boundary Waters Canoe area of northern Minnesota on Aug. 18. The fire tripled in size between this past Sunday and Tuesday.
Late arriving information expands to 100,000 acres the area which was burning Tuesday evening and predictions of powerful winds settling over the fire and much of the Midwest in coming days have to be worrisome to fire crews trying desperately to contain the blaze.
Winds are to blow toward Chicago from the fire in northeast Minnesota again Wednesday afternoon into Thursday. It's a set-up which could indeed deliver additional smoke to the Chicago area. But much of the smoke may arrive at a higher altitudes than Tuesday.
Lake breeze circulation critical in tapping densest smoke and lowering it to the surface Tuesday
Afternoon visibilities Tuesday dropped as low as 3 miles especially in lakeside counties. The development of a "lake breeze" there is forced air to sink offshore drawing dense smoke above the ground down to lake level where it was able to move onshore.
Dallas, Texas sets new all time annual record for triple digit temperatures with Tuesday's record busting 107-degree high
It finally happened in Dallas! The mercury soared to a record-breaking 107-degrees Tuesday bringing the 2011 tally of triple digit days to 70--a new record for the Dallas/Fort Worth Metroplex.
Another day of 100 degree-plus temperatures at Wichita Falls, Texas boosted the 2011 tally there to 100!
Get those extra blankets, jackets and sweaters ready! There's a formidable early season mass of cool air on the way which may produce frost patches in far northwest and west suburban locations in coming nights.
Chicago's earliest occurring 60-degree or lower daytime high in 15 years appears a real possibility Thursday as a huge Canadian high, extending 2,500 miles from north to south and 1,600 miles from west to east, settles southward into the Lower 48. Its central pressure is to be an impressive 1030 mb (30.42") when it arrives in North Dakota from Saskatchewan Wednesday evening.
The predicted Thursday high of 60-degrees at O'Hare would be 15-degrees below normal and more typical of a late October daytime reading than one in mid-September.
Chilly as a 60-degree high on Sept 15 would be, it's not a record---though it's not far from it. The record low max on the books here for Sept. 15 is 55-degrees set in 1993.
Freeze advisories posted for sections of 5 states
Sections of 5 states, from the Dakotas to Minnesota and northern Iowa, have been placed under freeze watches and warnings as the fresh batch of chilly air approaches. Though temperatures will be marginal for frost in Chicago's far west and northwest suburbs, mid 30-degree thermometer level temperatures, such as those predicted toward McHenry, Ogle, Lee, DeKalb, Boone and Winnebago counties, may well be cold enough to support a thin layer of freezing temperatures near the ground. In that environment some light patches of frost may form.
An official 32-degree or lower temperature last occurred at O'Hare April 21 and prospects a chill of that magnitude might occur in the city proper during the upcoming cool surge appears very low.
First 60-degree high last year arrived 10 days later; only one in ten years has seen highs this cool so early
Temperatures as cool or cooler than the 60-predicted Thursday at O'Hare didn't occur until Oct. 1-2 last year. That puts chill of this magnitude into the area nearly 2 weeks ahead of 2010.
In the past half century of observations at the O'Hare site, only one in 10 years has produced a 60-degree or lower high temperature by Sept. 15.
The Pagami Creek wildfire, responsible for Chicago's acrid shroud of smoke Tuesday, grows to 100,000 acres, triple its Sunday size
The eye-catching, orange-colored shroud of acrid-smelling smoke which settled over the Chicago area Tuesday afternoon originated in northeast Minnesota. Known as the Pagami Creek Wildfire, the blaze began with a lightning strike in the Boundary Waters Canoe area of northern Minnesota on Aug. 18. The fire tripled in size between this past Sunday and Tuesday.
Late arriving information expands to 100,000 acres the area which was burning Tuesday evening and predictions of powerful winds settling over the fire and much of the Midwest in coming days have to be worrisome to fire crews trying desperately to contain the blaze.
Winds are to blow toward Chicago from the fire in northeast Minnesota again Wednesday afternoon into Thursday. It's a set-up which could indeed deliver additional smoke to the Chicago area. But much of the smoke may arrive at a higher altitudes than Tuesday.
Lake breeze circulation critical in tapping densest smoke and lowering it to the surface Tuesday
Afternoon visibilities Tuesday dropped as low as 3 miles especially in lakeside counties. The development of a "lake breeze" there is forced air to sink offshore drawing dense smoke above the ground down to lake level where it was able to move onshore.
Dallas, Texas sets new all time annual record for triple digit temperatures with Tuesday's record busting 107-degree high
It finally happened in Dallas! The mercury soared to a record-breaking 107-degrees Tuesday bringing the 2011 tally of triple digit days to 70--a new record for the Dallas/Fort Worth Metroplex.
Another day of 100 degree-plus temperatures at Wichita Falls, Texas boosted the 2011 tally there to 100!
