textproduct: Medford

DISCUSSION

High pressure and dry northwest flow aloft will keep mostly dry weather going through the remainder of this week along with a warming trend. High temperatures today through the weekend will be 10-15F above normal. The air mass is pretty dry, but there will be at least a weak marine push from time to time that could produce periods of nighttime/morning stratus and/or fog along the coast, in the coastal valleys, and in the Umpqua Basin.

This afternoon, a weak shortwave will pass overhead within the northwest flow aloft. With a slight increase in atmospheric moisture, this impulse will likely pop off an extensive cumulus field this afternoon and evening over northern California, and a few more robust updrafts could grow into a light shower. The drier layers of the atmosphere should keep any of this precipitation from reaching the ground, but we can't rule it out. Similar conditions are expected again Friday afternoon and evening.

The ridge weakens late in the weekend, and the pattern aloft transitions to more zonal flow Sunday. Then, a trough from the Gulf of Alaska digs south over the area early next week, with a cold front passing through the area. Temperatures will cool significantly Monday, with highs dropping to near or slightly below normal for this time of year. Also of note, the passage of the front will bring gusty northwest winds Monday afternoon, especially over high terrain and across the East Side.

The main impact for the entire forecast area will be a much stronger signal for precipitation than we have seen in well over a week (outside of isolated showers). That said, there are discrepancies between global models on the timing, overall height fields, and hence coverage of precipitation chances. The takeaway here is there is at least a better signal for widespread precipitation than we have seen in recent weeks. Confidence is increasing for precipitation between Monday and Wednesday but details are still unclear.

As we maintain the dry airmass and breezy afternoons, there will be at least an elevated threat for fire weather conditions each day. However, fuel conditions per fire agencies reveal the overall fire weather threat will remain low to moderate. Given the low RH values each afternoon and breezy winds, people should exercise caution with any outdoor activities that could cause sparks or flames. Bottom line is that fire season was declared early this year, so these precautionary actions should already be in place, but its especially important when we have these elevated concerns.

AVIATION...21/12Z TAFs

VFR prevails area wide currently, with gusty N-NW winds closer to the coast (20-30 kt). Marine low clouds/fog have started to develop along the coast north of Cape Blanco and also the coastal valleys (Coquille, Umpqua). This will result in IFR/MVFR ceilings through the early morning hours at North Bend. Some clouds could also form in the Umpqua Basin around Roseburg, but these will be patchy and may avoid the terminal. Right now, probability of an MVFR ceiling at Roseburg is 15-20%. All lower flight conditions should improve through the late morning. For Medford and Klamath Falls (and elsewhere), expect VFR to prevail for the next 24 hours. -Spilde

MARINE...Updated 1200 AM PDT Thursday, May 21, 2026

A thermal trough will bring gusty north winds and steep to very steep seas over the coastal waters through Friday night. Winds will be strongest and seas will be highest during the afternoons/evenings. Through this stretch, very steep seas of 10-13 ft are most likely south of Cape Blanco with steep seas (6-9 ft) north of Cape Blanco. Gale force gusts (~40 kt) are possible across portions of the southern waters, especially from around Gold Beach south.

The pattern will ease some this weekend as an upper trough pushes in from the NW. This should bring lighter winds and lower seas (still at least Small Craft Advisory), especially by Sunday. Could be a brief break Sunday night, but models continue to show another trough moving through on Monday (Memorial Day). The strength and timing of this trough are still somewhat uncertain, but it could bring periods of rain, gusty W winds that shift back to N and steep seas. This one should be followed by a larger WNW swell. -Spilde

MFR WATCHES/WARNINGS/ADVISORIES

OR...CA...None.

PACIFIC COASTAL WATERS...Hazardous Seas Warning until 11 PM PDT Friday for PZZ356-376.

Small Craft Advisory until 11 PM PDT Friday for PZZ350-370.