Lingering cold air will bring another round of cool overnight lows tonight into Friday morning. A Freeze Warning is in place for the Rogue, Applegate, Illinois, and parts of the Klamath River Valley for early Friday morning. Frosty conditions may be possible in the Umpqua Valley, as that valley runs a little warmer.

A more stable pattern looks to guide conditions on Friday and Saturday, bringing a period of warm daytime highs and dry conditions. Saturday is forecast to be the warmest day of this period. Coastal areas may reach the low 60s, while west side valleys have forecast highs in the low 70s. To the east, expected temperatures in valleys and basins are on the mid to high 60s.

A low pressure system approaches the area on Sunday, but its modeled behavior seems to change from one run to the next. Current deterministic guidance limits precipitation to coastal areas on Sunday, and even that is uncertain. Ensembles for both ECMWF and GFS models have 50-60% chances for rainfall at North Bend on Sunday, with chances decreasing farther inland. The low dips farther south before hovering off the northern California coast. At this point, southerly flow could bring showers focused on Curry and southern Siskiyou counties. Snow levels of 5000-6000 feet at this point would allow for some mountain snow in western Siskiyou County, but widespread winter impacts look unlikely in this pattern.

The modeled low moves inland over Tuesday and Wednesday, allowing for widespread showers. Overall, nothing in this system`s forecast behavior looks especially threatening, but this is a very preliminary impression. Chances of winds exceeding 35 mph (a speed safely below Advisory thresholds) are minimal in NBM probabilistic guidance, topping out at 20-40% over the Warner Mountains in Modoc County and 10-20% over some other east side peaks through Sunday and Monday. Southerly flow can favor gusty winds developing in the Shasta Valley and over nearby terrain, but models struggle with that level of detail this far out. Forecast snow levels stay in the 5000-6000 foot range. Curry County, western Siskiyou County, and the Mount Shasta region could see 1 to 1.5 inches of rainfall in this timeframe. But to repeat, expectations for this system could change as models get a better hold of its potential. Past Wednesday, deterministic imagery starts to diverge. Meteogram guidance shows some expectation of a warm, dry period towards the end of next week.