Weather Outlook: Increasing concern for flooding Saturday night through Monday night.
The latest information from NWS Medford indicates increased concern about flooding. Heaviest rain for local region expected Sunday night into Monday night.
Wet weather will continue this weekend trough at least early next week. The first front is quickly moving east of the Cascades. A brief break in the steady precipitation is expected tonight into Saturday from the Cascades eastward, but another front will bring steadier precipitation back to coastal areas and then the Umpqua by Saturday morning.
Then, an atmospheric river (AR) will take aim on the forecast area Saturday night through Monday. With a source of moisture from near Hawaii, it will feature heavy rain and snow levels above 7000 feet. Snowmelt and increased runoff will result in significant rises to area rivers, streams, and creeks. Models have been consistent in showing the main heavy rain area from Curry County southward into western Siskiyou County with a wetter trend across northern California and portions of the East Side.
As such, small stream and urban flooding is likely in those areas, and main stem river flooding is possible. Forecast graphics below have been updated.
One front is quickly moving east of the area with a break in precipitation for most areas tonight. Another front will arrive at the coast late tonight/Saturday with steadiest precipitation west of the Cascades. That front will set up over the area with low pressure areas riding along it to maintain periods of moderate to heavy rain at the coast Saturday night through Monday.
Heavier precipitation will then push into northern California and east of the Cascades Sunday night through Monday night.
Latest model data have trended wetter across northern California (Shasta Region) and over portions of the East Side late Sunday through Monday. We have added Flood Watches for portions of south-central and SE Siskiyou Counties as well as east of the Cascades.
Snow levels above 7000 feet and heavy rain late Saturday through Monday will result in significant rises to area rivers, streams, and creeks, especially west of the Cascades and in Siskiyou County. There is increasing concern for flooding Saturday night through Monday night.
A few main stem rivers are expected to reach action stage/bankfull, and latest information is showing the Sprague River near Beatty reaching minor flood stage by Tuesday due to a combination of rainfall and snowmelt. We encourage you to keep a close watch on river forecasts, as well as our general forecasts and forecast discussions.
Landslides and debris flows are possible with this event. The Hooskanadan slide area could be particularly vulnerable to this heavy rain event.
Enhanced flash flood threat for wildfire burn scars, including the Klondike and Chetco Bar with peak rainfall rates of 0.50-0.75 of an inch per hour possible late Saturday night through Sunday evening.
Snow impacts will be minimal during the daytime, but there is potential for snow impacts across the high elevation areas like Crater Lake.
Below: Latest radar returns showing passing rain showers ahead of an atmospheric event that is expected later this weekend.