Some good news is in store for flood-ravaged Colorado this week. The weather pattern responsible for the tremendous and deadly flooding is moving away.
The mechanism responsible for bringing once-in-100-year rainfall rates to parts of Colorado was breaking off this week. In some cases, the rainfall rates exceeded a 100-year event.
Boulder, Colo., has received nearly 10 inches of rain since Sept. 8, 2013, which is 26 times the normal rainfall for the past week. Some locations have received nearly double this amount.
While there will still be spotty drenching thunderstorms over central Colorado this week, the activity will be far less persistent and much less concentrated compared to last week, thanks to dry air filtering in from the West.
The spotty storms can still cause incidents of flash flooding, but most streams and rivers over Colorado will recede over time this week. However, the runoff will work downstream into the other rivers over the Plains, such as the Platte River in Nebraska, where some areas could face record flooding.
While it will take a couple of days, incidents of flash flooding over Colorado become more isolated in nature as the week progresses.
Even though the rain will diminish, many roads will remain closed due to damage from washouts and debris flows.
According to Chief Meteorologist Elliot Abrams, "The persistent flow of tropical moisture is shifting away as a large area of high pressure moves farther to the east."
A band of tropical moisture over the interior West in recent weeks was being squeezed over Colorado last week. Meanwhile, circulation around high pressure over the Midwest was forcing additional moist air uphill over the Front Range and foothills of the Rockies.
"It is possible that a lack of organized tropical systems moving into the South Central and Southeastern United States so far this season may be partially to blame for the surge of heavy rain over the Rockies," Abrams said.
Large tropical storms and hurricanes tend to draw in moisture, near their center. The air becomes drier some distance away, suppressing rainfall and thunderstorms.
Moving forward, another zone of heavy rainfall will be setting up late this week into this weekend. This time, however, the rain will be centered over Texas and the southern Plains.
While much of the South Central U.S. needs rainfall, there is the potential for an excessive amount in some locations that could lead to flooding.
A northward push of tropical moisture will deliver showers and thunderstorms to the Tennessee and Ohio valleys through Sunday night.
Storms forced the termination of the Idaho-Florida college football game at Ben Hill Griffin Stadium after just one play.
lightly above-normal temperatures are expected through the Labor Day weekend across the Los Angeles area.
A change in the weather pattern will signal warmer, more summerlike conditions across the East Coast to bring in the new month.
Minneapolis is on the front line of a severe weather outbreak this Labor Day weekend.
Humidity and the threat of thunderstorms will continue in the Atlanta area through at least Tuesday.
The East (1966)
"Official" end of the East's worst drought. Some places had a 4-year deficit of nearly 4 feet.
Death Valley, CA (1971)
The high today was 108; the low 84. These were the coolest readings in the entire month. The average high during August was 115.7 degrees, and the low averaged 93.4.
Boise, ID (1984)
One-day-old Cadillac is crushed by a dumpster thrown by thunderstorm winds.