975 FXUS66 KMFR 270606 AFDMFRArea Forecast Discussion National Weather Service Medford OR 1106 PM PDT Fri Sep 26 2025
.Updated the Aviation and Marine sections...
.AVIATION...27/06Z TAFs...VFR conditions will continue through the TAF period for all terminals. The exception is locations west to southwest of the Moon complex where smoke could result in MVFR visibility. It`s not our of the question there could be a brief period of patchy shallow fog overnight, toward sunrise, at North Bend, but confidence is not high enough to include it in the TAF. Coastal IFR is expected to develop later Saturday evening. -Petrucelli/DW
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.MARINE...Updated 800 PM PDT Friday, September 26, 2025...A thermal trough along the Oregon Coast will maintain gusty northerly winds this evening with steep seas south of Cape Blanco, very steep seas south of Gold Beach, and below advisory seas north of Cape Blanco.
A transition to a dominant northwest swell starts on Saturday morning as winds decrease, limiting steep seas to waters south of Port Orford into Saturday afternoon.
Seas look to remain below advisory level from Saturday afternoon into Sunday afternoon. Then, an approaching front will bring gusty southerly winds, with steep to very steep and hazardous seas Sunday night into Monday. Active weather with a second front Monday night into Tuesday could include gales. Winds and swell from this second front could support hazardous wind/sea conditions continuing into midweek. -TAD/DW
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.PREV DISCUSSION... /Issued 510 PM PDT Fri Sep 26 2025/
DISCUSSION...Mainly sunny, dry and warm weather is expected today through almost the entire weekend as high pressure remains in place; Saturday will likely be the warmest day for much of the area.
A significant pattern change then occurs Sunday night into Monday. On Sunday, the dominant flow will become more southwesterly as a strong upper level trough develops over the Gulf of Alaska. We`ll probably eke out one more dry and warm day. By late Sunday, the trough will dig south over the northeastern Pacific, then send a cold front into the Pacific Northwest Monday, followed by another front Tuesday, then continuing showers Wednesday into Thursday as onshore flow persists and the trough axis passes onshore along the Oregon and Washington coastlines. In short, as September closes out and October arrives, it will definitely begin feeling much more like fall.
These fronts are likely to produce gusty south to southwest winds, below normal temperatures, and a very high chance of much- needed wetting rainfall area wide. It will be breezy everywhere as these fronts pass, but wind concerns will be concentrated along our typically wind-prone areas: the coast, the Shasta Valley, the East Side, and higher terrain, where wind gusts could peak up to 50 mph. We`ve adjusted NBM winds upward during this period to account for local terrain-induced effects, and should trends continue, Wind Advisories will likely be needed for the Shasta Valley and portions of the East Side, such as in the vicinity of Summer Lake. Meanwhile, with water vapor transport (IVT) values forecast to be quite healthy (especially for this time of year) and snow levels remaining well above pass levels, widespread rainfall is expected. Preliminary rainfall of 0.50 to 1 inch is forecast for most of the West Side, 0.25 to 0.5 inches over the East Side, and as much as 2-3 inches along the coast, the coastal mountains, and western Siskiyou County from Sunday night through Tuesday night. Showers are then expected to continue Wednesday and Thursday as the upper level trough passes overhead and onshore flow persists.
This will be the first event of its type this season, and the first significant front to pass through the region since early May. As a result of this and the usual lower skill of model guidance during seasonal transitions, confidence is lower than normal regarding the strength and timing of the fronts and the passage of the upper level trough. Also, with this being the first significant wind and rain event, some additional concerns arise. Summer-weakened trees could be more easily susceptible to damage, blocked drainages could result in ponding of stormwater, and rain could combine with oil/residue buildup on area roads, making them slicker than expected. Be aware of these hazards when out and about early next week.
The good news is, this could be a wildfire season ending event, at least for much of the area. That being said, dry and warm periods are still possible and have occured during October in previous years, so only time will tell.
Models are suggesting that high pressure will return by early next weekend, with the area drying out and temperatures warming back up to near normal Friday into Saturday. However, those same models show continued activity across the Pacific which could easily mean additional systems are possible by late in the weekend into early next week. So, changeable weather should be expected as we transition out of summer and into fall. -BPN/Spilde
FIRE WEATHER...Updated 200 PM PDT Friday, September 26, 2025... Warm and dry conditions continue today and into Saturday. Easterly flow over area peaks and ridgelines will bring another night of moderate to locally poor recoveries tonight into early Saturday morning. Recoveries across the Cascades and terrain in Siskiyou County are forecast to be only in the 25-35% range. The easterly winds should ease somewhat later tonight as the thermal trough weakens. We`ll maintain a headline for the dryness and elevated east flow, but warnings aren`t necessary.
While Saturday remains warm and dry, recoveries into Sunday morning increase. Southerly winds develop across the area Sunday, with gusty winds developing over east side terrain and into the southern Shasta Valley during Sunday afternoon. These winds may reach Advisory levels. Widespread wetting rainfall is likely as a couple of strong fronts move through the area, one late Sunday night into Monday and another Tuesday through Tuesday night. In addition to the wind/rain, Mon-Wed will also see higher than usual humidity and below normal temperatures. -Spilde/TAD
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.MFR WATCHES/WARNINGS/ADVISORIES... OR...CA...None.
PACIFIC COASTAL WATERS...Small Craft Advisory until 2 AM PDT Saturday for PZZ356-376.
Hazardous Seas Warning until 2 AM PDT Saturday for PZZ356-376.
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NWS MFR Office Area Forecast Discussion