textproduct: Medford

DISCUSSION

Updated aviation discussion for 06Z TAFs.

AVIATION...27/06Z TAFs

IFR/LIFR stratus and fog will impact the coast overnight into Thursday morning, gradually becoming VFR by late morning/early afternoon. The marine layer should be deep enough to impact Roseburg with MVFR ceilings Thursday morning. Model guidance is only showing about a 10% chance of an MVFR ceiling here in Medford, but hi-res models are showing some "spill over" into the Rogue Valley around sunrise. Confidence in this scenario is pretty low, but we've added a broken ceiling at around 3500 ft to indicate the potential and will reassess at the night moves along. Some of the higher terrain west of the Cascades could be obscured. Other than some high cirrus, VFR will prevail for the rest of the area through Thursday evening. Gusty west to southwest winds will occur Thursday afternoon/evening east of the Cascades (east of Klamath Falls) and in NE California with peak gusts in the 25-35 kt range.

Expect marine stratus to return to the coast and also portions of the Umpqua Basin Thursday night. -Spilde

PREV DISCUSSION

/Issued 258 PM PDT Wed Aug 26 2026/

KEY MESSAGES...

* Heightened fire weather concerns across the East Side through Thursday evening due to gusty winds and low RH.

* Weak instability just clipping far southeast portions of Modoc and Lake counties for a slight chance of thunderstorms late in the day on Friday.

* Temperatures trend cooler into Saturday, and remain near or below normal for the next week.

* Weather pattern largely influenced by upper level troughing, resulting in gusty winds in the afternoons/evenings, and night and morning coastal stratus extending into the Umpqua Valley for the early morning hours.

* Strong troughing Tuesday through Thursday next week for coastal rain chances, with the highest probability north of our area.

DISCUSSION...Model agreement/confidence in the forecast is high through Monday. A trough will be centered near the border with Canada through Saturday, then after brief ridging/slight warming and drying on Sunday, a stronger trough will quickly follow a similar track southeastward from Alaska beginning Monday. The exact track and strength of that trough is in question, but it is likely to be the main driver of our weather conditions during next week.

Over these next several days, the cooling trend and gusty, breezy afternoon and evening winds will continue. This will continue to bring heightened fire weather concerns, peaking during the afternoon/evening, particularly on Thursday, with stronger winds and RHs remaining fairly low. Fire weather concerns diminish some Friday onward as RHs trend higher, but with afternoons remaining breezy, and no precipitation expected (at least into Tuesday), fire danger remains very high across the region.

The only exception to a stable air mass, with dry mid-levels will be some tropical moisture being swept into the westerlies on Friday. Guidance brings this moisture into central CA/northwestern Nevada, then just clipping the far southeastern portions of Lake and Modoc counties.

The outlook is for the stronger trough to bring at least slight rain chances to at least the coast and Douglas County, and northward as early as Tuesday, with a focus from Tuesday night through Wednesday night.

MARINE...Updated 200 PM PDT Wednesday, August 26, 2026...Relatively calm conditions with light winds and low seas are expected into Friday morning. Southerly winds will persist today, then turn northerly on Thursday. North winds increase on Friday with steep seas expected south of Port Orford and within 30 nm of shore. Winds then strengthen further during the weekend, with steep seas likely south of Cape Blanco. Winds will be strongest during the afternoon and evening hours. Conditions are likely to improve Monday into Tuesday.

FIRE WEATHER...Updated 200 PM PDT Wednesday, August 26, 2026...

Critical fire weather conditions are anticipated east of the Cascades this afternoon and early evening as an upper level low remains off the Washington coastline. This low will move eastwards by Thursday with a dry cold front moving into the Oregon coast Thursday afternoon. Winds will trend slightly higher while humidities remain very low and perhaps hit the single digits in some areas. Critical fire weather conditions are likely in Modoc County and most of southern Lake and Klamath Counties Thursday. Lastly, the hot dry windy index has some confidence(~40%) that locations will exceed the 95th percentile for late August. Overall, pretty confident in a red flag occuring in southern Lake and Klamath Counties in addition to Modoc County Thursday.

By Friday, some tropical moisture will hit central California. The latest forecast is just clipping our region in Modoc County and southern Lake County. This has resulted in a low chance of showers or thunderstorms in the Warner Mountains Friday afternoon. If storms do form, it looks like they'll be moving fast. However, this scenario doesn't really fit our ideal lightning ignition event as we would like to see more instability.

Heading into Saturday, another upper trough will swing into the Pacific Northwest. We're expecting humidities to be higher while wind gusts are just not as strong over our forecast area. While fire weather conditions are not great, it doesn't appear we'll reach critical wind and humidity in our area Saturday.

The last thing we wanted to note was the improving recoveries Thursday night with very good recoveries Friday night. Some of this is due to deeper westerly flow across the region. However, the tropical moisture arriving Friday appears to help things significantly Friday night as some locations recover to 90% in the valleys of Klamath county.

Overall, Thursday is the day of highest concern with the fire weather threats decreasing into the weekend.

-Smith

MFR WATCHES/WARNINGS/ADVISORIES

OR...Red Flag Warning from 2 PM to 8 PM PDT Thursday for ORZ624-625.

CA...Red Flag Warning from 2 PM to 8 PM PDT Thursday for CAZ285.

PACIFIC COASTAL WATERS...Small Craft Advisory from 2 PM to 11 PM PDT Friday for PZZ356-376.