textproduct: Medford

DISCUSSION

Another morning of almost perfectly clear skies is in store southern Oregon and far northern California. Satellite imagery does however show an area of fog and low clouds rounding Cape Mendocino, and surging north towards the south coast. Brookings, which reached 96 degrees F yesterday at the airport, dropped to 64 degrees F in less than one hour once the Chetco effect shut off and marine influence returned. Now, with the coastal wind reversal approaching from the south, fog and low clouds are expected to reach Brookings around or shortly after sunrise, and get as far north as Gold Beach by late morning. These low clouds will shift offshore in the afternoon, but are likely to return tonight.

Heat will be the primary concern for the next few days. The thermal trough that has sat along the California and southern Oregon coast will push inland today, as a weakness in the strong upper level ridge settles southward into northern California. This is the mechanism that will result in that aforementioned surge of southerly wind up the coast that is acting as nature's air conditioning for the Brookings area today. Temps still could be in the 70s/80s early on, but we do expect onshore flow to provide cooling. The strongest offshore flow will shift to the north today and this will allow coastal areas near Coos Bay/North Bend to get much warmer than usual. We are expecting highs largely in the 80s, but possibly even around 90F if the afternoon northerlies stay more NNE. Areas inland just a few miles will have highs well into the 90s.

If the air conditioning has been turned on near Brookings, then the inland push of the thermal trough will turn the thermostat up to high heat for inland areas. All inland areas west of the Cascades, as well as the Mount Shasta City area will see high temps of 95-105F through Tuesday. Even a few locations in the lower Klamath river valley in western Siskiyou County will get close to 110F. Heat Advisories have been issued for all these areas starting today, including the north coast, and will spread into the Klamath Basin and also the rest of norCal east of Mt. Shasta City on Monday, where highs of low to mid 90s are expected with moderate heat risk. Those who are sensitive to heat or lack cooling/hydration resources could be affected by heat- related illnesses.

Recent trends in the guidance suggest that there will be some cooling from the NW Tuesday as the thermal trough shifts farther inland. As such, the advisories for Coos and Douglas counties end a bit sooner than the rest.

The ridge is expected to flatten a bit at midweek as a strong upper jet becomes directed across southern British Columbia into northern ID/MT. As such, the reduction in heat has been muted a bit over the latest few model cycles. Temperatures are now expected to cool only slightly Wed/Thu, as in around 5 to 10 degrees, then lower towards more seasonable, but still above normal temperatures Fri into next weekend as an upper level trough digs in from the northwest. As mentioned over the past few days, we tend to see an increased risk for thunderstorms on the back side of heat waves. Models are still keeping the area mostly dry at the end of this one, but models are showing increasing signs of instability in some runs as early as Wednesday afternoon, but moreso Thursday and especially Friday afternoon, mainly over Modoc and Siskiyou counties as the trough moves into the area. Moisture values in the model runs are increasing, now with PWATs approaching 1 inch, and the trough itself is likely to act as a sufficient trigger. So while chances are very low/low (~10-15%) for Wed, they are increasing for Thursday, and are now solidly in the forecast for Friday over portions of northern California and the East Side. The exact timing and location of thunderstorm risk are difficult to pin down due to model differences at this time range, but confidence is increasing for thunderstorms somewhere in our area Thursday, and especially Friday, afternoons. -Spilde/BPN

AVIATION...14/12Z TAFs

North to northwest winds will not be as strong this afternoon with breezy northerly winds limited to the coast north of Cape Blanco. Coastal IFR/LIFR presently well to the south near Cape Mendocino will surge northward through this morning. LIFR is expected to reach Brookings around 13Z, Gold Beach around 15Z, and persist through around 18Z. For Sunday afternoon and early evening, the stratus is expected to retreat offshore from the immediate coast. After 03Z Sunday evening into Monday morning, the LIFR/IFR is forecast to return to the south coast and continue expanding north to around Cape Blanco. Otherwise, clear skies/VFR conditions will persist across the area.

MARINE...Updated 100 AM PDT Sunday, June 14, 2026

The thermal trough will push inland Sunday, allowing winds to weaken temporarily. Although winds diminish, residual fresh swell and wind seas will keep waves steep for all areas, potentially very steep south of Gold Beach, though latest guidance shows seas easing from around 6-7 feet down to 4-5 feet during the afternoon at Buoy 46027 (Pt. St. George). Also, a wind reversal is likely south of Gold Beach and within 20 nm of shore, where a southerly wind surge could produce reduced visibilities in fog.

The thermal trough quickly reforms Monday and Tuesday, bringing the return of strong north winds and steep to very steep wind driven seas through much of next week. -Spilde/BPN

FIRE WEATHER...Updated 100 AM PDT Sunday, June 14, 2026

Rapid warming and drying continue as an early season heat wave lasts through midweek. Temperatures will peak Sunday to Tuesday with daytime highs about 20-25 degrees above normal. This will likely result in some triple digit readings for the valleys west of the Cascades, but especially western Siskiyou County, where it could get to around 110F. Minimum relative humidities will also trend lower (bottoming out in the 10-20% range for most areas) -- though RHs could even drop into single digits at times, especially over the East Side deserts and some of the West Side valleys. Meanwhile, broad north through east flow will produce moderate to poor RH recoveries over upper slopes/ridges each night, especially over the Klamath mountains, Siskiyous, and Cascades. Poor ridge RH recoveries are likely again Sunday night. Expect another round of enhanced northerlies to channel through the Goose Basin near Lakeview this morning.

Elsewhere, expect fairly typical diurnal afternoon N-E winds that could become breezy at times during the afternoons/evenings through Tuesday. This will make for elevated fire weather concerns into early next week and localized conditions could get extremely close to Red Flag criteria, especially considering the low teens and potential single digit minimum humidities during the peak of the heat wave, along with the afternoon breezes. Undoubtedly, this period of hot, dry, breezy weather will continue to move the needle toward higher fire danger as we head into next week.

We continue to see a signal in the extended forecast as the heat begins to ease mid next week that moisture/instability will increase. As such, lightning potential will increase. Right now, models are showing focus areas mainly to our south through Thursday. However, there is a low possibility (10-15% chance) that something pops up in some of our southern and eastern mountains (Mt Shasta region/Warners) Thursday afternoon/evening. But, by Friday afternoon/evening, the signal remains stronger for a slight chance of thunderstorms in those same general areas (SE sections of the forecast area). We'll continue to monitor and adjust the forecast as necessary. -Spilde/BPN

MFR WATCHES/WARNINGS/ADVISORIES

OR...Heat Advisory until 11 PM PDT Tuesday for ORZ021-023>026-029.

CA...Heat Advisory until 11 PM PDT Tuesday for CAZ080>085.

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT Tuesday for PZZ350-356-370-376.