textproduct: Medford

KEY MESSAGES

* Fire weather conditions this afternoon and evening just shy of critical thresholds of wind and humidity in much the same portions of the area that did reach those levels yesterday. This includes the Shasta Valley, eastern Siskiyou, Modoc, southeast Klamath and southwest Lake Counties.

* Hot, very dry, breezy, and unstable conditions will continue this weekend.

* Smoke will persist for Jackson, Klamath, and Siskiyou counties through the weekend, with some temporary afternoon into early evening improvement expected for Klamath and Siskiyou counties. Also, an influx of smoke into Lake County from fires in central Oregon.

* Thunderstorms re-enter the forecast beginning as early as Monday, mainly for the Cascades and east side. The highest risk will be on Tuesday and Wednesday, including lesser chances for areas west of the Cascades.

* Conditions late next week are indicated to bear some resemblance to those from the past couple of days, with a dry and slightly cooler forecast, accompanied by enhanced afternoon winds that would be strongest east of the Cascades.

DISCUSSION

The upper level trough that has been offshore over the past few days will track northeast into British Columbia today. This will be just enough to relax pressure gradients slightly, but breezy to windy afternoon and evening winds will again be stronger than normal today. Humidity levels, though not quite as extreme as yesterday, will also again be much drier than normal. High pressure will build in Sunday and continue the warming trend while further weakening pressure gradients. As such, our weather for the rest of the weekend will resemble that of the past couple of days.

By Sunday night and continuing into Monday, a plume of monsoonal moisture aloft will bring high clouds into the area. This could generate a few showers, mainly over the higher terrain, but also mainly virga. Weak instability on Monday afternoon is expected to generate a few thunderstorms with a focus on the Cascades into northern Klamath County.

On Tuesday into Wednesday, southerly flow aloft is expected between a trough offshore tracking northward and the persistent ridge over the Great Basin. There is more uncertainty in the convective forecast. But also, more potential for a significant amount of thunderstorms as well as a potential for activity on the west side. A larger portion of the suite of ensemble members does indicate a majority of activity from the Cascades eastward and isolated rather than scattered coverage.

Model uncertainty increases another notch on Thursday, but the region of instability is likely to shift east-northeastward. This could bring another day of thunderstorm activity to the east side, or shift the activity east and northeast out of area.

For Friday into Saturday, the pattern has some resemblance to the current picture. This would result in a dry forecast, but a slow moving dry front would also produce enhanced afternoon and evening winds, strongest on the east side.

AVIATION...18/12Z TAFs

Gusty winds will develop again this afternoon, strongest along the coast, in the Shasta Valley and east of the Cascades.

VFR skies will prevail across most of the area through the TAF period. One exception will be impacts from wildfire smoke that will bring periods of MVFR visibilities and/or ceilings to the Rogue Valley, Klamath Basin, and Shasta Valley including Medford, Klamath Falls, and Montague. Smoke from central Oregon fires will also impact Lake County, including Lakeview.

The other exception will be marine stratus along the coast and offshore as LIFR and IFR ceilings and visibilities persist into mid- morning. By this afternoon, VFR conditions will return to coastal locations.

MARINE...Updated 200 AM PDT Saturday, July 18, 2026

Gusty north winds are maintaining steep seas south of Cape Blanco, before steep seas spread to all waters late this morning. As north winds maintain a lengthy peak this afternoon through Sunday evening, very steep seas will develop south of Port Orford. Conditions gradually improve on Monday with steep seas likely as dominant wind waves transition to fresh swell. Further improvement follows Tuesday into Wednesday as low pressure moves up from the south late Tuesday and Wednesday. This low may remain well offshore and weaken as it moves north.

FIRE WEATHER...Updated 200 AM PDT Saturday, July 18, 2026

The main update this morning is some further clarity on an expectation of weak instability with a modest risk of thunderstorms on Monday afternoon, as well as a heightened risk for more signficant coverage and strength of thunderstorms on Tuesday and Wednesday afternoons.

The three main aspects of the fire weather forecast for the next week are: first, the extent of hot, dry, and breezy/windy conditions today through Sunday, second, the potential risk and coverage of thunderstorms while inland temperatures remain above normal during Monday through Thursday, and lastly, a likely transition to dry and slightly cooler weather late next week that would likely be accompanied by stronger than normal east side westerly winds.

The forecast through the weekend is consistent and pretty straight- forward. Hot temperatures at 5 to 10 degrees above normal will continue to trend slightly upward, humidities will remain significantly drier than normal, and breezy afternoon winds will trend just slightly weaker today than yesterday, before returning to typical strength for Sunday afternoon. The slight moistening of the air mass on Sunday will be accompanied by a late day increase of high clouds, and perhaps some east side cumulus buildups.

Instability could develop as early as late Sunday night into Monday morning, with a few very light showers or virga possible over the higher terrain. A slight chance risk of thunderstorms is expected Monday afternoon, with the highest probability of thunderstorms over the Cascades. Then, on Tuesday and Wednesday, there is a greater uncertainty regarding the area of focus, but also a greater concern that both a significant amount of lightning may develop and coverage may include the west side...east of the Coast Range. For now, the NBM forecast is utilized with a slight chance of mainly east side thundertorms on Tuesday and Wednesday.

Late in the week (Thursday/Friday), some eastward movement in the pattern is likely, which is likely to shift the region of instability east of our area. But, a plausible, slower solution would keep instability and some slight thunderstorm risk over eastern portions of Lake and Modoc counties.

MFR WATCHES/WARNINGS/ADVISORIES

OR...CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory from 11 AM this morning to 11 PM PDT Sunday for PZZ350-356-370-376.

Hazardous Seas Warning from 5 PM this afternoon to 11 PM PDT Sunday for PZZ356-376.