CHICAGO, IL – JUNE 26: Wrigley Field is shown during the seventh inning of a game between the Chicago Cubs and the Washington Nationals on June 26, 2014 in Chicago, Illinois. (Photo by David Banks/Getty Images)

The fog was so dense in Chicago Thursday that the Wrigley Field umpiring crew considered delaying the game between the Cubs and the Washington Nationals.

From the Post’s sports writer James Wagner:

The apartment buildings and rooftop seats just outside the stadium were out of sight all afternoon. Every half-inning, thick fog rolled in and out, making it hard for players to see. Outfielders were fuzzy masses from the stands.

Nationals center fielder Denard Span lost a fly ball in the blinding fog, resulting in a triple for the home team.

The fog has resulted from the interaction of lake-cooled air over Lake Michigan and a flow of warmer, humid air from the east and northeast off the land.  As the stream of warm, moist air from the east has collided with the lake-cooled air, it has risen and condensed forming an envelope of fog that has then spilled over Chicago’s lakefront.

The effect of the lake-cooled air early this summer season is especially strong thanks to colder than normal waters over Lake Michigan, a parting gift from the brutal polar vortex winter in which ice extent on the Great Lakes challenged record levels and Chicago experienced its third snowiest winter on record.

Notes the Chicago Sun Times: “The water temperature at the south buoy, which sits in the middle of Lake Michigan due east of Racine, Wisconsin, was 46 degrees Fahrenheit, said Ben Deubelbeiss, a meteorologist with the National Weather Service in Romeoville.”

The chilly waters have given rise to multiple bouts of fog this month.

“Chicago has had 32 hours of fog and low clouds this month — quadruple normal levels, according to the National Weather Service,” writes the Chicago Tribune.

Winds coming in from the south – off the land rather than the chilly water – promise to cut off the fog into this afternoon and over the weekend.

Here are some remarkable views of the fog from the past two days, via Twitter:

Cover up Chicago #fog #chicago #chitecture #aon #officeview
Photo cred @knl2811 :) #chicago
hello and see you later foggy #chicago #vscocam
And the funky #weather continues. #Chicago
#chicago #chitown #insta_chicago #fog