textproduct: Medford

DISCUSSION

Currently, southern Oregon and far northern California lie under cloud-free skies as high pressure builds in overhead. These clear skies will allow for good radiative cooling, with this morning's lows expected to be just slightly below normal for this time of year. Additionally, frost is expected east of the Cascades this morning, and a Frost Advisory is in effect for many locations there. More details on this can be found at PDXNPWMFR. This may be the lats time we speak of cool temperatures for some time, however.

A broad trough over the Rockies and Central Plains will shift east over the coming days, allowing the upper level ridge over the eastern Pacific to amplify and build into the western US through this weekend. Meanwhile, with high pressure in control, a thermal trough will strengthen along the coast, with temperatures in and around Brookings expected to rise well into the 80s each day. 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 into Sunday 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 also 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 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.

The ridge is expected to flatten a bit by Wednesday. This could be delayed by as much as a day, as these pattern 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 tend to see an increased risk for thunderstorms on the back side of heat waves. Currently, 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 county. 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.

AVIATION...11/12Z TAFs

Patchy late night into early morning IFR/LIFR is possible in the lower portions of the Coquille and Umpqua valleys, but unlikely. Also, breezy to gusty northwest to north afternoon and evening winds will develop again on Thursday. Otherwise, VFR with clear skies will continue across the area through Thursday night.

MARINE...Updated 100 AM PDT Thursday, June 11, 2026

A strengthening thermal trough will produce 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 develop by tonight and persist through the weekend. Winds will ease on Sunday, but steep fresh swell is likely to persist into Monday, with north winds strengthening again around Tuesday.

FIRE WEATHER...Updated 100 AM PDT Thursday, June 11, 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. Meanwhile, broad east flow will produce moderate to poor ridgeline recoveries each night, especially over the Klamath, Siskiyous, and Cascades.

The heat wave will culminate Sunday through Tuesday, with daytime highs about 20 to 25 degrees warmer than normal for early to mid June. Our typical diurnal afternoon breezes could become gusty at times, particularly on Friday. 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.

Also of note, once the heats 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.

MFR WATCHES/WARNINGS/ADVISORIES

OR...Frost Advisory until 7 AM PDT this morning for ORZ029>031.

CA...Frost Advisory until 7 AM PDT this morning for CAZ084-085.

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 from 2 PM this afternoon to 11 PM PDT Saturday for PZZ356-376.