textproduct: Medford

DISCUSSION

Marine stratus still covers much of the coast and Umpqua Basin this afternoon. We're also watching some cumulus build ups along the Cascades as the atmosphere begins to destabilize. The Cascades and most of northern California will be areas to watch for thunderstorms this afternoon. Convective available potential energy(CAPE) is modest around 500-750 J/kg, which is enough to support some stronger storms for our area. Upper level shear is also about 20 to 30 knots out of the east. Main threats will be some gusty winds and sporadic lightning through this afternoon and early evening.

Thunderstorm activity will diminish tonight as the atmosphere begins to stabilize. There could be some patchy fog along the coast tonight and perhaps in some of the smaller river valleys. The GFS and NAM are both showing some light QPF along the coast, and that usually suggests some drizzle mixed with fog in the marine layer. In any case, just something to watch out for tonight.

The upper level low bringing all these thunderstorms will move eastwards through the day on Tuesday into southern California as high pressure begins to build over our region. The net effect will be warming temperatures above normal for this time of year as highs push into the lower 80's here in Medford on Tuesday and mid to 80's through the rest of the week. Looking at Medford's climate data, we'll be about 15 degrees warmer than the normal highs for this time of year.

Towards Thursday, models are showing a short wave riding over the top of this ridge in Washington. 850mb equivalent potential temperature maps are showing a dry cold front approach our area around early Thursday, yet it never really moves through according to the GFS. With that said, our official forecast trends down from 85 degrees to the upper 70's on Friday, perhaps due to cloud cover and the breaking down of the ridge. Our best chance at more precipitation is towards Friday evening when the PoP is around 5-10% in our Oregon areas. Essentially, it's looking pretty dry and warm through the week.

AVIATION

18Z TAFS MVFR ceilings will continue along the coast for the majority of the TAF period with some clearing in the Umpqua Basin near RBG later this afternoon. Showers and thunderstorms will start popping up later this afternoon and evening over northern California and the Cascades. These storms could produce some gusty outflows as they move westwards. Fog and marine stratus will cover the coast with some light drizzle and IFR ceilings later tonight.

MARINE

Updated 100 PM PDT Monday, May 4, 2026 An extended period of relatively calm conditions will continue through much of this week with west-northwest swell dominated seas likely remaining below 10 ft through Friday. Light south winds and fog are expected through tonight, with gradually diminishing seas. Moderate north winds likely develop on Friday, with the return of the thermal trough.

MFR WATCHES/WARNINGS/ADVISORIES

OR...None.

CA...None.

PACIFIC COASTAL WATERS...None.