textproduct: Medford

Update AVIATION Discussion

AVIATION...17/00Z TAFs

VFR conditions prevail across the region with isolated showers continuing in the Umpqua Basin, east of the Warners and over the Modoc Plateau. This shower activity will diminish after sunset and skies will clear. VFR conditions will continue for most areas through Friday afternoon, but there is the chance for some patchy fog to develop in the Umpqua and Coquille Basins, possibly resulting in LIFR conditions at Roseburg and North Bend late tonight. If these lower conditions develop, expect improvement to VFR by Friday morning. /BR-y

PREV DISCUSSION

/Issued 114 PM PDT Thu Apr 16 2026/

DISCUSSION...As the large upper level trough passes to the east today, light rain showers are expected to continue through this afternoon and taper off this evening. With clear skies tonight and cold air settling in, we are forecasting another cold night/morning, with frost and freeze conditions across much of the region. A Freeze Warning is in place for the Rogue, Applegate, Illinois, and parts of the Klamath River Valley for early Friday morning, with a Frost Advisory in effect for the Umpqua and Coquille basins.

A more stable pattern with high pressure overhead will 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 there is wide variation on how it will track. Current deterministic guidance limits precipitation to coastal areas on Sunday, and even that is uncertain, as some ensembles keep precipitation offshore. Overall, across both ECMWF and GFS suites, there is a 50-60% chance 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. This pattern is also favorable for thunderstorms, with Monday and Tuesday afternoons looking as the most likely time periods for thunderstorm development (around 15-20%).

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. Ensemble trends show some expectation of a warm, dry period towards the end of next week.

MARINE...Updated 200 PM PDT Thursday, April 16, 2026...Fresh north- northwest winds and steep seas persist through this afternoon, highest south of Port Orford. Seas could be around 10 ft. Winds ease some this evening, but a weak thermal trough will develop and maintain gusty north winds/steep seas south of Cape Blanco into early Saturday morning. Low pressure offshore will bring a return to active weather late this weekend into next week. -Spilde

MFR WATCHES/WARNINGS/ADVISORIES

OR...Freeze Warning from midnight tonight to 11 AM PDT Friday for ORZ024-026.

Frost Advisory from midnight tonight to 11 AM PDT Friday for ORZ021-023.

CA...Freeze Warning from midnight tonight to 11 AM PDT Friday for CAZ080.

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 PM PDT this afternoon for PZZ350-356-370-376.