textproduct: Medford

DISCUSSION

A Pacific ridge is stuck between two upper lows (an omega block) while an upper trough around the Gulf of Alaska is flattening the ridge from the north. This pattern is causing the ridge to bulge over the area, resulting in daytime highs 5 to 15 degrees above average across the area today and on Sunday. For today, most areas are expected to see high temperatures on the low to mid 60s. Brookings and parts of the Klamath River Valley are already approaching 70 degrees early this afternoon. Onshore flow has supported marine stratus and fog along Coos County coastal areas, keeping temperatures cooler than expected. While satellite imagery shows this area clearing out, continuing onshore flow may allow marine stratus to rebuild later this afternoon.

On Sunday, the changing shape of the upper ridge will move the highest temperatures to Modoc and eastern Siskiyou counties. Forecast highs for those areas have come down slightly. Highway 89 south of the Mount Shasta region still has a 50-70% chance to see temperatures above 70 degrees, and the Klamath River Valley will stay warm as well. the chances for those conditions around Adin and Alturas have dropped to 0-10%. So while these areas will see temperatures in the mid to high 60s, getting into the 70s seems unlikely. The Klamath River, Scott, and Shasta Valleys will also be in the mid to high 60s. Southern Curry County looks to cool to the low 60s, and other areas will see similar temperatures as they did on Saturday.

On Monday, the ridge flattens further and allows zonal flow with some northwestern tilt to become the influential pattern. A tight gradient between the Pacific ridge and Gulf of Alaska trough will guide moisture to the Pacific Northwest, although much of this moisture looks to stay north of our area. As where the moisture arrives changes based on how models handle the Alaska trough and the Pacific ridge, slight chances (20-50%) for precipitation are a near- constant feature along the coast and Cascades through this week. Overall, forecast precipitation amounts are measured in the hundreths and will be unimpactful where showers do develop. Elevated terrain will experience breezy to gusty afternoon and evening winds through much of the week ahead, but current forecast speeds are safely short of Advisory levels.

Two features in this pattern will bring minor effects to local conditions, but hazardous conditions are not expected through the forecast period. The first feature of interest is the expectation of cold air advection to start the week. This will bring below seasonal daytime highs and cool nighttime lows on Monday and Tuesday. As this cold air moves over the area, snow levels periodically drop to 1500- 2000 feet. However, given the generally dry conditions and the absence of an atmospheric lifting mechanism moving over the area, winter impacts are not a concern currently. At most, a few isolated snow showers are possible. Given residual surface warmth from the weekend, accumulation is unlikely. Frosty conditions are possible for coastal areas. Monday night into Tuesday morning looks to have the lowest temperatures across the area, but freezing concerns are low as NBM probabilistic guidance has a 0-30% chance for lows below 32 degrees along the coast.

The second feature is that the low pressure system over the Gulf of Alaska may start to drift east towards Thursday, which could flatten the Pacific ridge just enough for increased precipitation chances over west side areas. With the ridge flattening but otherwise staying in place, heavy rainfall is not expected. With snow levels towards the end of the week forecast to be at least 5500- 6500 feet, any snowfall would be limited to peaks and ridgelines. Showers could continue into Friday and the weekend, depending on the position of the ridge and trough in this period. -TAD

AVIATION...07/18Z TAFs

IFR/LIFR fog/low clouds persist along the coast from Bandon and the Coquille Valley north (including North Bend) at least for the next hour or so (20Z), then should break to VFR for a while this afternoon before returning to IFR/LIFR again tonight into Sunday morning (around 03Z). Inland, satellite shows the low clouds and fog in the Umpqua Basin eroding with VFR expected this afternoon and most of tonight. Areas of fog and LIFR conditions are expected to redevelop in those same areas (and also likely Roseburg) for a few to several hours late tonight and Sunday morning. We don't think precipitation will occur, but there is a low chance of light coastal rain north of Cape Blanco. There is a chance of shallow fog at Medford around sunrise Sunday morning. Elsewhere, expect VFR conditions. -Spilde

MARINE...Updated 230 PM PST Saturday, March 7, 2026

Expect advisory level north winds and steep, choppy seas through Monday night south of Port Orford. Lighter winds and lower seas are expected north of there. North winds strengthen a bit on Monday, especially south of Cape Blanco, where steep seas will persist. There is a ~60% chance for very steep, short period seas (10-11 ft/7 seconds), south of Gold Beach Monday afternoon/evening. Improving conditions are possible on Tuesday as the dominant wind seas transition to west-northwesterly swell. Even so, the WNW swell arriving will be borderline for small craft advisory (10 ft/13 seconds). This swell decays Tuesday night into Wednesday with winds shifting to SW. Mid-late week, guidance shows a front stalling nearby to the north. This would keep the core of the windier, more unsettled weather to the north, but with additional westerly swells moving through. -Spilde

MFR WATCHES/WARNINGS/ADVISORIES

OR...CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PST Tuesday for PZZ356-376.

Hazardous Seas Watch from Monday morning through late Monday night for PZZ356-376.