Thanks to Gina Tedesco for sharing the gorgeous colors at The Morton Arboretum.
Nyssa sylvatica, or sour gum tree.
East side of the Arboretum.
Thanks to Connie Koehler for this shot of the Eau Claire River in central Wisconsin.
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By Meteorologist Tom Skilling
Wednesday's 66-degree high was the Chicago area's coolest in 9 days and the most seasonable of any since Oct. 4. Readings are to peak at comparable levels Thursday.
A glimpse at Chicago's temperature records proves we could be a lot worse off. It's been a whole lot cooler at this point in the season on many occasions in the past. Only a year ago, the area was five days into a stunning 7-day run of unseasonably cool days---each with daytime highs which failed to break out of the 40s. But the same observational record offers evidence we're probably not done with 70-degree temperatures. An average of five additional 70-degree or higher readings has typically occurred from this date forward. And we need look no further than Saturday to see what looks likely to be the city's next 70-degree day.
Thundery cold frontal passage starts the temperature pullback
The current temperature downturn began early Wednesday with a thundery cold frontal passage. The rains these thunderstorms produced were, in most instances, the first to fall in 10 days. Though the lightning and sharp claps of thunder garnered immediate attention in affected areas, most Chicago area rain tallies were light and unimpressive.
O'Hare and Midway, the city's two official observation sites, received just 0.10 and 0.20 inches respectively. But, in a few harder hit areas, situated most directly beneath some of the stronger cells which affected the area---the tallest among them Doppler-scanned with cloud tops to 43,000 ft.--- ended up with unofficial half inch or greater tallies. Included among these were 0.60- and 0.63-inch totals at the Weather Bug rain gauges in the Lawndale neighborhood at King Elementary and Kellman Corporation Community School, 0.55 inches in Wicker Park at Diego Community Academy and at Hillside 0.39 and Oak Lawn 0.32 inches.
Wednesday morning's thunderstorms here blast areas to the east with hail, high winds
Noisy as early Wednesday's storms were here, it was sections of Indiana which bore the brunt of the day's most impressive storms. Wind damage was reported at Kokomo, Ind. where gusts hit 64 mph, while Marion was bombarded by hailstones the size of golf balls.
By late Wednesday, thunderstorms made their way into Ohio and Kentucky. The thundery complex of storms was predicted to undergo eye-catching intensification by Friday morning, developing into a mammoth storm along the mid-Atlantic and New England coasts.
Northeast and Mid-Atlantic brace for "bombogenesis"; wind, rain, high surf to hammer the area with deepening storm
Storm development can be incredibly vigorous along the East Coast, because, in part, of the heat energy developing storms are able to tap from the Atlantic to fuel their development. Forecasters up and down the East Coast have come up with a term which covers explosive storm development in that region: "bombogenesis". A storm with a central pressure which drops at least 24 millibars in 24 hours---a stunning rate of intensification---is said to be undergoing "bombogenesis".
Such a storm is to come together over the coming 24 hours along the Eastern Seaboard. The moisture expected to ride the system's rapidly strengthening winds, which may gust to 70 mph at times late Thursday night into Friday on the coast of Maine, could lay down 3-inch-plus rains at the hardest hit locations and possible local 6 inch or greater snows above the 3,500 ft. level in the Adirondacks, White and Green Mountains from New York state into New Hampshire and Vermont
Reinforcing chill the length of Lake Michigan hits Chicago Friday setting stage for lake effect clouds, showers
An influx of high and mid-level cloudiness Thursday marks the approach of a new lobe of still cooler air expected to ride into the Chicago area behind another cold front late Thursday night. The reinforcing cool shot is to ride into the metro area on winds which shift northerly and run the length of Lake Michigan into the city Friday.
With air temperatures a mile above the lake to drop to 37 degrees, the stage is set for lake-effect cloud and rain shower formation Friday.
Daytime temperatures may reach no higher than the low 60s Friday---but should warm to around 70 Saturday with the return of southwest winds. It's next week which may see the season's coolest air invade. Early indications show temperatures by mid-week may rise no higher than the mid or upper 50s.
Should I believe news reports that ice exists on Mercury?
Believe it. Mercury, the innermost planet of our solar system, rotates around the sun at a distance less than half of Earth's 93 million miles. Temperatures at Mercury's equator reach 800 degrees Fahrenheit and, as Dr. David Williams of NASA's Goddard Space Flight Center writes, "Mercury would seem to be one of the least likely places in the solar system to find ice. ... The local day on ... Mercury is 176 Earth-days, so the surface is slowly rotating under a relentless assault from the sun."
However, radar imaging of Mercury has revealed areas of high radar reflectivity indicative of ice near the north and south poles. Williams says, "Presumably, the ice is located within permanently shadowed craters where it may be cold enough for ice to exist."