textproduct: Medford

KEY MESSAGES

* Dry weather is expected for inland areas through Thursday with above normal warmth and fairly typical afternoon breezes.

* Nightly marine pushes will bring cooler air and stratus to the coast, and also a chance of drizzle.

* Offshore low pressure brings heightened fire weather concerns Friday with gusty winds and at least a slight chance of thunderstorms.

* Breezy winds continue Saturday with a slight cool down.

* Dry, warmer weather returns Sunday/Monday.

DISCUSSION

Upper ridging will amplify a bit over the area through Thursday resulting in above average warmth for inland areas (NWS HeatRisk tops out as minor with pockets of moderate, especially in the typically hotter valleys). Despite the elevated risk, this type of heat is common for late August and primarily impacts those who have heat sensitivities or lack adequate cooling/hydration systems). Even so, this will be a hotter period, so try to find ways to keep cool and stay hydrated. Expect highs in the mid to upper 90s for the west side valleys south of the Umpqua Divide with even some triple digit readings in the lower Klamath river valley of western Siskiyou County. East side locations and the Umpqua Basin will have highs in the upper 80s and lower 90s. Nightly marine pushes will continue at the coast bringing periods of low stratus/fog and even a chance of drizzle at times. From around Port Orford to Gold Beach, it should stay comparatively clear due to a slight offshore wind component. Coastal areas will have highs in the 60s/low 70s.

A closed low well offshore will get a kick north-northeastward Friday into Saturday as it gets absorbed into the westerlies. At the very least, this will bring an increase in W-SW winds in NorCal and from the Cascades eastward and NW winds in the west side valleys Friday. Models continue to differ on timing, strength and position of the low as it moves northeastward across the PacNW. And, this has some impact on the forecast - especially thunderstorm chances. Will the low be close enough to the coast so that forcing is better or far enough offshore that most of the forcing stays offshore or to our north? There should at least be some moisture and instability available due to SSW flow aloft. So, there's a slight chance of showers and thunderstorms Friday afternoon/evening, but the best chances at this time are up across the north (easternmost Douglas, northernmost Klamath/Lake counties). The associated upper trough should swing through on Saturday. By then, most of the moisture will lift to the north (mentionable PoPs stay north), but gusty afternoon/evening W-NW breezes could persist. Either way, we should see a cooling trend Fri/Sat compared to the mid week warmth.

It should dry out and turn warmer again Sunday/Monday with the flow aloft turning more into the south Monday into mid next week. This could increase chances for t-storms again, but it's only a low chance at this time (5-10%). -Spilde

AVIATION...18/18Z TAFs

Satellite imagery shows stubborn marine stratus along the coast north of Cape Blanco, including at North Bend and south of Pistol River, including at Brookings. This is resulting in IFR ceilings currently at North Bend and LIFR ceilings/fog at Brookings. Sandwiched in between is an area of VFR (Gold Beach to Port Orford) due to a more offshore wind component. Where the lower conditions are currently, we expect conditions to improve somewhat this afternoon with some areas scattering out to VFR around 21Z, but this will be short-lived. We expect IFR/LIFR conditions to redevelop this evening and continue overnight into Wednesday morning.

Inland, mainly VFR is expected through Wednesday morning with just some high and mid level clouds. -Spilde

MARINE...Updated 230 PM PDT Tuesday, August 18, 2026

Gusty north winds and steep seas, highest during the afternoons and evenings are expected south of Cape Blanco through Wednesday evening. Conditions are expected to improve Thursday and Friday. A thermal trough will redevelop along the coast this weekend bringing a return of strong north winds and steep seas. Once again, strongest winds and highest seas are most likely south of Cape Blanco. -Spilde

FIRE WEATHER...Updated 130 PM PDT Tuesday, August 18, 2026

Aside from some enhanced afternoon breezes today, fire weather concerns will remain fairly standard for this time of year through Wednesday. Expect typical summer conditions with dry weather across the area and nightly marine pushes along the coast. Temperatures will trend upward today through Thursday, resulting in a downward trend in afternoon RHs. Overall, recoveries will remain in the moderate to good range, though poor to moderate recoveries are expected along and east of the Warners as well as the Salmon Mountains in western Siskiyou County through Friday morning.

Thursday will be a transition day into a pattern that brings some heightened fire weather concerns. A stronger upper level trough, currently spinning out beyond 140 W, will gradually move eastward this week, moving inside of 130 W by Thursday. This will start a period of increased winds that will likely persist through Saturday as this low pressure gradually moves inland into the PacNW through the weekend. Gusty winds are expected to develop Thursday afternoon as the trough nudges closer, and this could overlap with low RHs in portions of northern California and east of the Cascades, possibly resulting in critical conditions on Thursday.

There is some uncertainty regarding just how strong winds get and this could be the limiting factor on Thursday. There are subtle differences in the model guidance on how close to shore that low pressure is on Thursday, which will be a player in how strong winds are. Gusts 15 to 25 mph will be common across the region, but if the closer to shore solutions are correct, the windiest locations (Shasta Valley/East Side) could see gusts of 25-30 mph on Thursday. Confidence is higher for winds to peak on Friday (gusts 25-35 mph), but the limiting factor for critical conditions could be the uptick in daytime humidities expected Friday as temperatures trend cooler.

In addition to winds/RH concerns for Friday, mid-level moisture increases Thursday and Friday, raising the concern for thunderstorms potential. Current guidance indicates that the best chance for storm development would be along the Cascades from Crater Lake northward and across northern Klamath/Lake Counties. With the approach of the trough Thursday night into Friday, we're monitoring the potential for any nocturnal convection, but current guidance is steering clear of that for now.

Heading into Saturday, models differ a bit on how fast that trough moves through the region, but confidence is fairly good that the thunderstorm threat will shift north of the area. The question that lingers from these differing solutions is how strong will winds be on Saturday, especially east of the Cascades. While it's likely to be another breezy day, most areas should see weaker winds on Saturday compared to Friday. Some solutions would maintain another day of stronger winds across the Modoc Plateau and east of the Warner Mountains. Regardless, daytime RHs look similar to what's expected Friday, so again, that could be limiting factor for critical conditions on Saturday. Stay tuned for updates. /BR-y

MFR WATCHES/WARNINGS/ADVISORIES

OR...CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT Wednesday for PZZ356-376.