textproduct: Medford

DISCUSSION

Updated aviation discussion for 00Z TAFs.

AVIATION...28/00Z TAFs

Areas of IFR/LIFR stratus and fog will develop and impact the coast from Cape Blanco northward, including North Bend, tonight into Friday morning. Patchy IFR/LIFR ceilings/fog could also develop along the coast south of there this evening; these will become more widespread south of Pistol River overnight into Friday morning.

Once again, there should be enough moisture to cause MVFR ceilings to develop in the Umpqua Basin, around Roseburg, for at least several hours late tonight into Friday morning before clearing to VFR in the afternoon.

It should remain VFR in the Rogue Valley, including Medford and while Klamath Falls will have some high clouds at times, VFR will prevail there as well.

Coastal areas will have gusty N breezes (~25 kt) Friday afternoon, while areas east of the Cascades and in NE California have gusty S-SW afternoon winds (20-30 kt). Isolated showers/thunderstorms could graze far SE sections of the area Friday afternoon/evening, especially out around the Warner Mtns of Modoc/southern Lake counties. -Spilde

PREV DISCUSSION

/Issued 239 PM PDT Thu Aug 27 2026/

KEY MESSAGES...

* Today: Critical fire weather conditions continue for eastside areas, including areas of Klamath and Lake counties in Oregon and parts of Modoc County in northern California.

* Tomorrow: Chance (15-30%) for thunderstorms over far eastern Modoc County and southeast Lake County with lightning being the main threat.

* Temperatures are mostly seasonable through Monday (Saturday is a bit cooler), but next week is shaping up to have below normal temperatures through much of the week as a system passes through.

* System next week could bring rainfall in addition to the cooler temperatures. Rainfall chances increasing midweek and continuing through later parts of next week, especially westside areas.

DISCUSSION...

A closed upper level low off the coast of British Columbia will meander over this general area for the next several days. This will result in continued southwesterly flow aloft that will keep the forecast area generally dry as this trough pattern maintains (small exception for tomorrow). This pattern will maintain gusty winds and low RH today, but improvement in fire weather conditions look to develop Friday and continue through the weekend.

On Friday, an upper jet streak looks to develop between the aforementioned low and an area of high pressure over the Desert Southwest. This could help trigger a couple thunderstorms through peak heating as convective temperatures will be reached. While we have increased moisture, PWATs are not overly impressive, so not expecting a lot of rain. Main threat will be lightning, but if a storm or two can maintain in our area, we could have isolated gusty winds as well. Overall, the limited instability may only lead to isolated chances with better chances east of our area.

By Sunday, it does appear this upper trough pattern will shift east and we will briefly transition to a zonal pattern, but another trough pattern looks to quickly form over the west coast by Monday. In fact, It looks like a couple discernible troughs will transition the PacNW next week. There is some uncertainty in some of these cases where deterministic models vary on the timing, orientation, and strength of the upper pattern, but the overall pattern does appear to favor a trough. The increased rainfall chances do make sense given this pattern, but some of the finer details are a little hazy at this time given the model differences. It does also look like westside areas will be favor under this pattern. It should also be noted this doesn't appear to much rainfall for any of our locations. Westside areas will be favored, but the highest probability for any 24hr time period is only 60% for 0.05" of rainfall for Wed/Thurs. Coastal areas would be the higher probability for this rainfall, especially Coos County and western Douglas County. Instability looks very feeble across our forecast area, so not expecting much--if any--thunderstorms under this pattern next week. All that said, given uncertainty in the upper levels, it is advisable to check back as the forecast may change for both rainfall amounts and thunderstorm possibilities. If nothing else, increased cloud cover and cooler temperatures is looking very favorable Tuesday through middle/later parts of next week.

AVIATION...27/18Z TAFs...Fair weather cumulus will continue this afternoon along the coast with mainly clear VFR skies farther eastwards. We'll see another round of IFR stratus and visibilities along the coast. Fog down to 1/4 is possible at times, especially closer to Brookings.

-Smith

MARINE...Updated 100 PM PDT Thursday, August 27, 2026...Relatively calm conditions with light winds switching to the north this afternoon and low seas are expected through tomorrow morning. North winds increase tomorrow afternoon with steep seas developing south of Cape Blanco. These steep seas and gusty winds will persist through the weekend. Winds will be strongest each afternoon and early evening Friday through Sunday. Conditions are likely to improve Monday afternoon.

MFR WATCHES/WARNINGS/ADVISORIES

OR...Red Flag Warning until 8 PM PDT this evening for ORZ624-625.

CA...Red Flag Warning until 8 PM PDT this evening for CAZ285.

PACIFIC COASTAL WATERS...Small Craft Advisory from 2 PM Friday to 5 AM PDT Monday for PZZ356-376.