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UPDATE: 2 p.m. Monday
Minor flooding is expected to continue into Monday afternoon, prompting the National Weather Service to issue a flood advisory.
“Ponding of water in low spots and in poor drainage areas will continue this afternoon. Radar indicates moderate rain will continue for another couple of hours before tapering off late this afternoon,” the agency advisory said.
Ontario recorded 1.39” of rain in six hours on Monday, Aug. 21. That puts the day into the records books – so far – as the third rainiest day in recent Ontario history. The record is 1.59” that fell on Sept. 14, 1959.
Forecasters say up to an inch more rain could fall through the afternoon.
“This is causing urban and small stream flooding. Overflowing poor drainage areas have already caused minor flooding,” the advisory said. “In hilly terrain there are hundreds of low water crossings which are potentially dangerous in heavy rain. Do not attempt to cross flooded
UPDATE: 12:55 p.m. Monday
Jim Maret, Nyssa city manager, said the flood threat in Nyssa has receded.
“We are in good shape,” said Maret. Maret said several intersections in town flooded earlier today but they are now clear.
UPDATE: 12:30 p.m. Monday
The City of Ontario has designated a sandbag pickup area for those who may face flooding at the fire training center on Northeast 3rd Avenue. To reach the area, drive north on North Oregon Street and turn right onto Northeast 3rd Avenue. The sandbagging station is at the end of Northeast 3rd Avenue. The city is providing sandbags for those who need them.
UPDATE: 10:30 a.m. Monday
The National Weather Service reports that Ontario had 1.06″ of rain in the three-hour period ending about 9 a.m.
UPDATE: 10 a.m. Monday
Flooding is occurring on some streets in Ontario and Nyssa and ODOT reports rock falls on U.S. Highway 20 west of Harper and also east of Juntura. High water and mud are impacting travel on Oregon Highway 201 about one mile south of Adrian.
The National Weather Service reports the storm is moving north faster than expected. “Due to the speed that everything is moving, it does appear that the heaviest precipitation will be over by late afternoon/early evening,” according to the agency.
UPDATE: 5:30 a.m. Monday
The National Weather Service has cut back the amount of rain forecast for Ontario on Monday, Aug. 21, but renewed a flood watch for Malheur County through Monday evening. Forecasters say Ontario could get .50 to .75 inches of rain on Monday.
At 5:30 a.m. Monday, Ontario was getting light rain but Caldwell, Idaho, was reporting heavy rain.
The agency said early Monday that “the heaviest rain is yet to come” for the area as remnants of Tropical Storm Hilary continue moving north out of Nevada.
“Expect record-setting rainfall” is forecast “will likely produce flash flooding, rock slides and debris flows,” the agency said.
“Up to 1.5″ of rainfall is possible this morning especially across Harney and Malheur Counties in Oregon and the Lower Treasure Valley in Idaho,” the forecast said.
Ontario’s 1-day record for rain
- 1.59 – Sept. 14, 1959
- 1.40 – Dec. 24, 1968
- 1.35 – Jan. 8, 1993
- 1.19 – Jan. 8, 1996
- 1.18 – Aug. 14, 1979
- 1.10 – May 5, 2005
- 1.08 – Dec. 15, 1977
- 1.05 – March 4, 1983
- 1.04 – Aug. 14, 1968
- 1.03 – May 21, 1998.
Records dating to 1945 (National Weather Service)
The heaviest rain in 40 years is expected through Malheur County as the remnants of a hurricane move north on Monday, according to the National Weather Service.
The track of what was Tropical Storm Hilary in California on Sunday, Aug. 20, shifted to the west from what had been predicted earlier, with a path now straddling the Malheur-Harney county line.
A flood watch remains in effect through Monday evening.
“Expect record-setting rainfall today and Monday across the region associated with the remnants of Tropical Storm Hilary. This will likely produce flash flooding, rock slides and debris flows,” the National Weather Service in Boise said in a Sunday afternoon update to its flood watch.
Meantime, the Oregon Department of Geology and Mineral Industries on Sunday issued an alert for landslides and debris flows.
“Debris flows are rapidly moving, extremely destructive landslides. They can contain boulders and logs transported in a fast-moving soil and water slurry down steep hillsides and through narrow canyons,” the agency said in a news release. “They can easily travel a mile or more. A debris flow moves faster than a person can run. People, structures, and roads located below steep slopes in canyons and near the mouths of canyons may be at serious risk.”
Malheur County experienced such a debris flow in June, when thunderstorms triggered flows that buried sections of U.S. Highway 20 east of Juntura.
Stephen Parker, lead forecaster in the Boise weather service station, said in an interview Sunday that thunderstorms that moved over portions of Malheur County on Saturday primed some areas for such debris flows.
He said the forecast calls for 1.39 inches of rain in Ontario through Tuesday. The one-day record was set on Sept. 14, 1959, with 1.59 inches of rain. Baker City is forecast to get 1.75 inches.
Ontario City Manager Dan Cummings said city leaders would gather Monday morning if not sooner to assess the impacts of the storm. He said the city may stage sand and sand bags for citizens to use.
But the heavier rain is expected in rural areas of the county.
“Northern Malheur County is going to get hit hard,” Parker said, with up to 2 inches of rain expected.
He said the heaviest rain will be from about 4 a.m. Monday until noon.
“This is a very unusual event,” Parker said.
He said the strongest winds will be gusts to 30 mph in the southern end of Malheur County on Monday afternoon. In Ontario, winds are forecast to peak at 15 to 20 mph.
In its statement, the Department of Geology and Mineral Industries provided advice in anticipation of debris flows:
• “Listen. Unusual sounds might indicate moving debris, such as trees cracking or boulders knocking together. A trickle of falling mud or debris may precede larger landslides. If you think there is danger of a landslide, leave immediately.
• “Watch the water. If water in a stream or creek suddenly turns muddy or the amount of water flowing suddenly decreases or increases, this is a warning that the flow has been affected upstream. You should immediately leave the area because a debris flow may soon be coming downstream.
• “Travel with extreme caution. Assume roads are not safe. Be alert when driving, especially at night. Embankments along roadsides may fail, sending rock and debris onto the road.”
Parker added that the National Weather Service has standing advice for motorists who encounter water over a road: Turn around, don’t drown.
“Don’t drive on a road if the water is deep enough that you can’t see the road,” Parker said. He said washouts could leave car-swallowing holes hidden beneath that water. “It’s not worth your life” to test the water depth.
National Weather Service:
Oregon Department of Transportation:
Food and Drug Administration:
HELP REPORT: If the weather turns severe as forecast, help the Enterprise by sending sharing photos or information about what’s happening your area. You can message the information via Facebook or email Editor Les Zaitz: [email protected]