textproduct: Medford

KEY MESSAGES

* Daytime highs 5 to 15 degrees above normal continue today and Friday, supporting an extension of a Heat Advisory through Friday evening.

* Wildfire smoke accumulation continues this morning, with improvement possible on Friday and into the weekend.

* A slight pattern change to zonal flow looks to bring temperatures back to seasonal norms by next week, with little indication of impactful conditions in the forecast period.

DISCUSSION

An upper ridge remaining over the area will keep temperatures 5 to 15 degrees above normal across the area through Friday. The Oregon coast will be in the low to mid 70s through the rest of the week. The Umpqua Valley will be in the high 90s to low 100s while most other west side valleys linger near 105. the Klamath River Valley will have the hottest spots in the CWA. with highs reaching or exceeding 110. To the east of the Cascades, daytime highs in valleys and basins will be in the mid to high 90s. With constant high temperatures comes warmer nights and less chance for relief. For this reason, a Heat Advisory for most inland areas has been extended through Friday evening to highlight these hazardous conditions. Individuals who are sensitive to the heat or lack adequate cooling and hydration may experience heat-related illnesses with these ongoing temperatures.

With gentle overnight winds allowing for smoke accumulation, air quality looks to be a concern through the morning as well. Most areas will see some amount of smoke to start the day, but westerly flow aloft looks to change the pattern going forward. West side areas should see decreased accumulation on Friday morning, with east side areas still seeing some lingering smoke. Improving morning air quality may continue over the weekend.

That change to a westerly flow pattern will also help to slowly and steadily decrease temperatures across the area through the weekend and into next week. But even with the change in direction, the flow aloft stays relatively dry and free of substantial energy. A few weak disturbances may bring enhanced afternoon breezes at some point next week, but there's nothing to indicate worrisome conditions at this point. Long-term ensemble guidance supports this forecast, with both ECMWF and GFS modeling showing a seasonable period through much of the week ahead. -TAD

AVIATION...06/12Z TAFs

IFR to LIFR ceilings under a solid layer of marine stratus persisting along the Oregon coast. This layer looks to clear out this afternoon, but onshore flow looks to bring IFR/LIFR levels back this evening and into the end of the TAF period.

Inland areas looks to generally remain at VFR levels under clear skies, although wildfire smoke may bring periods of MVFR visibilities to area terminals through the TAF period. -TAD

MARINE...Updated 830 PM PDT Wednesday, August 5, 2026

Below advisory conditions continue today with lower wave heights due to north wind waves and fresh swell. North winds are expected to strengthen Friday through the weekend, with steep seas likely south of Cape Blanco. A small craft advisory is in effect for Friday over the southern waters, and this will likely expand in coverage through the weekend.

FIRE WEATHER...Updated 100 PM PDT Wednesday, August 5, 2026

Ridging aloft and a thermal trough at the surface will produce persistent heat and near-critical to critical fire weather concerns through the week. Temperatures will peak at about 10 to 15 degrees above normal today and Friday, before cooling slightly to more normal or just slightly above normal values by late this weekend and early next week.

Poor RH recoveries continue overnight, but should see some very gradual improvement through the rest of the week. Meanwhile, daytime minimum humidities will continue to be very dry, dropping into the low teens or single digit percentages in many locations, but these too should see some gradual improvement. Winds also remain breezy each day, with the usual diurnal pattern of breezy northwest winds in the afternoons, and broad east flow overnight. With these hot, dry, unstable, and windy conditions in the valleys during the day today, we are expecting to reach critical conditions across much of the area west of the Cascades. A Red Flag Warning is in effect for the Illinois and Rogue valleys, the Umpqua Basin, and western and south central Siskiyou County this afternoon and evening.

Some slightly improved conditions on Thursday will help reduce fire weather concerns a bit, but critical fire weather conditions are still expected in the Rogue, Illinois, and Applegate valleys yet again. A new Red Flag Warning has been issued for these areas for Thursday afternoon.

As humidities improve, and temperatures start to cool Friday into Saturday, further Red Flags may not be necessary, but some locations may still get very close to critical criteria. We will also have to watch for the potential passage of a dry front Saturday, and another early next week, that could produce enhanced winds and additional concerns.

Outside of the Red Flag Warning areas, for the rest of this week conditions will still be hot, dry, windy, and unstable, with poor ridgetop and east side recoveries, but conditions should stay below critical thresholds.

MFR WATCHES/WARNINGS/ADVISORIES

OR...Heat Advisory until 11 PM PDT Friday for ORZ023-024-026-028>031.

Red Flag Warning from 2 PM this afternoon to 8 PM PDT this evening for ORZ620-622.

CA...Heat Advisory until 11 PM PDT Friday for CAZ080-081-083>085.

Red Flag Warning from 2 PM this afternoon to 8 PM PDT this evening for CAZ280.

PACIFIC COASTAL WATERS...Small Craft Advisory from 2 AM to 8 PM PDT Friday for PZZ356-376.