textproduct: Medford

AVIATION...26/18Z TAFs

Marine layer stratus is eroding, but will maintain patchy MVFR ceilings along the coast north of Cape Blanco and into the Coquille and lower Umpqua valleys into the early afternoon. This improvement will be brief. A weak front will bring a more extensive push of MVFR marine stratus after 22Z, both extending into the coastal valleys and lowering to IFR at the coast early in the evening with about a 10% probability of very light showers at the coast. The stratus surge will continue into the Umpqua Valley after 05Z, with MVFR expected at Roseburg/KRBG after 10Z, then lingering through Thursday morning.

Elsewhere, VFR conditions will prevail with typical summer time diurnal breezes, increasing high clouds, and the potential for a few patches of stratus to extend over the Umpqua Divide into Josephine County/Grants Pass early Thursday morning.

MARINE...Updated 830 AM PDT Wednesday, August 26, 2026

Relatively calm conditions with light winds and low seas are expected into Friday morning. Southerly winds will persist today, then turn northerly on Thursday. North winds increase on Friday south of Cape Blanco, then likely strengthen further during the weekend.

PREV DISCUSSION

/Issued 254 AM PDT Wed Aug 26 2026/

KEY MESSAGES...

* Temperatures trend cooler today, trending cooler through the week into the weekend.

* Weather pattern largely influenced by upper level troughing, resulting in gusty winds in the afternoons/evenings.

* Heightened fire weather concerns across the East Side through Thursday due to gusty winds and low RH.

DISCUSSION...Southwest flow persists over the region today with persistent high pressure over the the Desert Southwest and low pressure offshore. This low pressure will gradually move inland into the Pacific Northwest over the remainder of the week...a pattern quite similar to that of last week. With this trough, temperatures will gradually trend cooler over the remainder of the week, eventually settling into the 80s area wide (except for the coast) for the weekend behind the trough passage. Persistent onshore flow will bring the nightly return of marine layer intrusions along the coast, and eventually into the Umpqua Basin Thursday morning. Expect periods of increased mid and high level cloud cover as shortwaves pass through in southwest flow ahead of this trough.

Aside from the cooler temperatures, the main concern with this trough will be increased afternoon winds each day through Thursday. This will bring heightened fire weather concerns each afternoon/evening as daily winds increase and RHs remain fairly low. Fire weather concerns diminish some Friday onward as RHs trend higher, but with no precipitation expected anytime soon, fire danger remains very high across the region. Please remember to do your part and prevent a spark. One less spark, one less fire.

The mid-levels will be too dry to support any thunderstorm development this week, and while no widespread precipitation is not expected through the forecast period, some of the guidance is showing some tropical moisture being swept into the westerlies on Friday. Current guidance brings this moisture into central CA/northwestern Nevada, which could clip the southeastern portions of the forecast area or remain just south, depending on how it interacts with the trough passing inland at the same time. Overall, the thunderstorm threat is minimal, but it's something worth watching this week.

Broad troughing will remain over the western CONUS over the weekend and into early next week. Dry conditions likely continue for most areas with temperatures near to a few degrees below normal. There are some indications in the extended guidance for the potential for a more wet front to move onshore at some point next week (mid-latter half). It certainly doesn't look like a widespread precipitation scenario, but more of a weakening front as it moves onshore scenario. This scenario focuses the highest chances for precipitation (only light amounts at that) along the coast, into the Umpqua Basin and areas northward. Of the 00z/26 ensemble solutions, about 50% show some amount of precip along the coast and in the Umpqua Basin, with about 15-25% showing lighter amounts farther inland (Medford, Klamath Falls, Mt Shasta City). The GEFS suite is more bullish with inland/southward extent compared to the EC suite. It's still early in the forecast period to have any confidence in this coming to fruition, and often times, we see these precip chances lower as the time gets closer, or get pushed later in time over future model runs. Confidence is higher for continued cooler temperatures through next week, but we'll just have to wait and see how precipitation chances trend.

FIRE WEATHER...Updated 200 AM PDT Wednesday, August 25, 2026... Southwest flow will persist over the region through much of the week. The upper level pattern will largely be dominated by an upper level trough over the eastern Pacific that will move inland into the Pacific Northwest. This pattern is quite similar to that of last week, when gusty winds combined with low daytime RHs and brought critical fire weather conditions. This will again be possible through Thursday, potentially Friday as well, as this trough brings gusty winds in the afternoons/evenings. With low daytime RHs expected, near critical conditions are possible each day, with critical conditions also possible in the Shasta Valley and portions of the East Side.

RHs will trend lower across the East Side today and Thursday while winds will trend a bit stronger as a dry front gradually moves inland. These two days seem most likely for gusty winds/low RH to overlap and result in critical conditions for portions of the East Side. A Red Flag Warning is in effect for this afternoon and a Fire Weather Watch is in place for Thursday afternoon, both for Fire Weather Zones (FWZs) 285 and southern 624/625. Gusty winds will continue on Friday (maybe just a bit weaker thought), but RHs trend upward which could limit the concern for critical fire weather conditions on Friday. Another dry front/upper level trough passes through the region on Saturday, bringing another round of gusty winds, though generally weaker compared to this week. Also, RHs likely remain elevated enough through the weekend to lower the concern for critical fire weather conditions.

Meanwhile, onshore flow will generally maintain moderate to good recoveries with nightly marine pushes for coastal zones. The exception to this could be Thursday morning when poor recoveries are possible along the Warners and southern portions of the Fremont- Winema National Forest. Thunderstorms remain out of the forecast. Guidance maintains an area of increased moisture moving into central CA/northwest NV, which could bring some precipitation to the southeastern corners of Modoc/Lake counties on Friday. Instability isn't all that impressive for our zones at this time, but can't rule out an isolated thunderstorm on Friday for those areas.

MFR WATCHES/WARNINGS/ADVISORIES

OR...Red Flag Warning until 8 PM PDT this evening for ORZ624-625.

Fire Weather Watch from Thursday morning through Thursday evening for ORZ624-625.

CA...Red Flag Warning until 8 PM PDT this evening for CAZ285.

Fire Weather Watch from Thursday morning through Thursday evening for CAZ285.

PACIFIC COASTAL WATERS...None.