A hot, dry fall
Alecia Warren | Hagadone News Network | UPDATED 12 years, 1 month AGO
COEUR d'ALENE - I know what you're thinking: 'If this is fall in Idaho, why didn't I just stay in California?'
It's hardly trick-or-treating weather yet in Kootenai County: Sunshine still steaming down relentlessly, not a spec of rain cluttering the skies. Throngs are still hiking and biking in shorts, embracing the thermostats teetering around the 70s.
Even our eyes are denied the seasonal promise: Most trees remain a sea of chlorophyll, delaying the usual coppers and golds.
This faux fall will continue at least through the first half of October, said climatologist Cliff Harris.
"We may be seeing a change in two to three weeks from now," Harris said. "I would tell people, enjoy the good weather while we have it."
For the past several weeks, a high pressure ridge has domed the Inland Northwest like a "pot lid," Harris said, keeping the area in tinderbox conditions.
The period from July 20 to Oct. 1 was the driest on record, with only .23 inches of precipitation, compared to .37 in 1934.
This year saw September go completely rainless for only the third time since 1895.
"We're seeing a situation here where one spark could create a real wildfire," Harris said.
There will be a break in the heat midweek, with highs in the 60s and lows near freezing. But afterward, temperatures will pop back into the 70s, he said.
"No rain in sight," Harris added.
The conditions the week of Oct. 15-22 will determine the rest of the season, he predicted.
If the high pressure ridge stays put, he said, that means more tank top weather and drought.
But if it breaks up, exposing the region to a low pressure trough, there will be a deluge like the record-setting moisture that plagued the spring.
"Don't expect normal, no matter what," Harris said. "Either we're going to be way drier and hotter than normal, or we'll be wet, cold and miserable."
Leaves won't shift shades without the magic combination of cooler and shorter days, said Dorothy Kienke, Master Gardener program coordinator at the University of Idaho Extension Office.
"We just have not had cooler triggers for the fall foliage," she said.
Waning sunlight slows leaves' production of the green pigment chlorophyll, according to the U.S. Forest Service website. Other color pigments then become dominant, and multiply in cool temperatures.
A summer drought like this year's can also delay the onset of fall color by a few weeks, the USDA site states.
The lack of moisture has sent many leaves straight to brown, Kienke noted.
"Now that people aren't watering, leaves are turning for a different reason, rather than the changing of colors," she said.