textproduct: Medford

DISCUSSION

We're having another clear night in southern Oregon and far northern California. Cool overnight temperatures are being experienced across the region, but we will warm up quickly again today. The warm trend continues late this week into the weekend, culminating in a broad heat wave expected during the Sunday to Tuesday (maybe Wednesday - esp east side) time frame.

A broad trough over the Rockies and Central Plains will shift east over the coming days, allowing an upper level ridge over the eastern Pacific to amplify and build into the western US through this weekend. With high pressure in control, a thermal trough has strengthened along the coast, with temperatures in and around Brookings expected to rise well into the 80s again today and Saturday. Models show the peak of offshore flow tonight into Saturday morning, so it could be quite warm at the mouth of the Chetco tonight (not much cooling) as the NE winds funnel down the river valley. With onshore flow lacking into Saturday, it could conceivably reach into the 90s, even though current models don't explicitly show that potential. Inland, temperatures will rise by 2 to 5 degrees over the previous day each afternoon into this weekend.

The upper level ridge will weaken slightly Saturday night as a trough interrupts the flow briefly, then the ridge rebuilds quickly and remains overhead through the first part of next week. This interruption will push the thermal trough inland, and this will result in very warm temperatures Sunday through Tuesday/Wednesday. Daytime highs across the area will be 20 to 25 degrees above normal for early to mid June, with widespread triple digit, or upper 90s, highs west of the Cascades, and upper 80s to low 90s to the east. Model forecast 850 temperatures (a very reliable signal for daily highs) are forecast to reach 26 to 28 degrees C, which when mixed to the surface (especially now during our longest daylight hours of the year), suggest highs could reach as high as 105 degrees F in Medford and Grants Pass, and as high as 110 in the lower Klamath and Salmon valleys in western Siskiyou County. These will be the highest temperatures we have seen so far this year, and chances are very good that we will see record daily highs for many locations across the region. NWS HeatRisk is showing widespread moderate impacts with areas of major impacts. At this time, it appears as if nighttime temperatures will be somewhat of a mitigating factor to the heat, since most areas should be able to cool off adequately. As such, this looks like an advisory level event. We'll be evaluating the need for heat headlines over the next couple of shifts.

The ridge is expected to flatten a bit by Wednesday. This could be delayed by as much as a day, as these patterns typically are, which will let temperatures cool slightly through the rest of the week. However, temperatures are still expected to remain above normal. Of note, we also tend to see an increased risk for thunderstorms on the back side of heat waves. As has been the case over the last few shifts, model suites keep the area dry at the end of this one, but there are some hints of instability starting to appear in some runs on Wednesday or Thursday afternoon, mainly over Modoc and Siskiyou counties. The limiting factor will be atmospheric moisture, which appears lacking as of now, and a clear trigger to set off convection. So while chances are very low now, we can not rule out some lightning around the middle of next week. Confidence should improve as we get closer to the time period in question, and model better resolve the situation. -Spilde/BPN

AVIATION...12/12Z TAFs

VFR levels persist across northern California and southern Oregon under stable atmospheric conditions. Chances for cloud development over North Bend and along other coastal river valleys near sunrise remain, but chances for a dense enough layer to affect flight levels remain slight. If stratus does develop, clearing is expected within a few hours after sunrise. Gusty winds are expected along the coast and possibly at the Roseburg terminal late Friday morning and through the afternoon. -TAD

MARINE...Updated 100 AM PDT Friday, June 12, 2026

A thermal trough pattern will maintain gusty north winds and steep to very steep wind-driven seas across the southern Oregon coastal waters through this weekend. The worst conditions are expected south of Cape Blanco, where gales and very steep seas will persist through the weekend. Winds ease some on Sunday, but steep fresh swell is likely to persist into Monday. Gusty north winds likely strengthen again around Tuesday. /BR-y

FIRE WEATHER...Updated 100 AM PDT Friday, June 12, 2026

A steady warming and drying trend is expected through the rest of this week, culminating in an early season heat wave this weekend into early next week. Generally, temperatures will warm by 3 to 5 degrees and humidities will trend about 3 to 5 percent drier each afternoon (minimum RHs 10-20%). Meanwhile, broad north through east flow will produce moderate to poor RH recoveries over upper slopes/ridges each night, especially over the Klamath mtns, Siskiyous, and Cascades. There could be a period of gusty offshore E-NE winds over the Siskiyou Mtns and coast ranges Friday night/Saturday morning with peak gusts in the 25-35 mph (40 mph?) range.

Our typical diurnal afternoon breezes could become gusty at times, particularly Friday/Saturday. While critical conditions are not expected within the current forecast, localized conditions could get close, especially considering the low teens and single digit minimum humidities that are likely during the peak of the heat wave. The heat wave will reach a peak Sunday through Tuesday, with daytime highs about 20 to 25 degrees warmer than normal for early to mid June.

Also of note, once the heat begins to ease midweek, we will need to keep an eye out for possible thunderstorms. Model guidance is not currently showing any significant convection chances, but there are some hints in the various model suites, and thunderstorms do typically accompany the breakdown of a heat wave in this area, so there is at least a very slight potential, probably focused on far northern California and the East Side. Confidence is low right now, but we will update the forecast as necessary over the coming days. -Spilde/BPN

MFR WATCHES/WARNINGS/ADVISORIES

OR...Heat Advisory from noon today to 8 PM PDT Saturday for ORZ022.

CA...None.

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

Small Craft Advisory until 11 PM PDT Saturday for PZZ350-370.

Gale Warning until 11 PM PDT Saturday for PZZ356-376.