textproduct: Medford

KEY MESSAGES

*A much drier air mass moves into the area today and will persist for at least the next 7 days.

*Overall, temperatures will be very warm, but should be pretty close to or just slightly above normal for late July.

*Other than daily intrusions of marine stratus along the coast (and perhaps a slight chance of drizzle at times), cloud cover will be minimal and precip chances will be near zero for inland areas.

*Little to no risk for thunderstorms during this time period, but there will be periods of strong, gusty winds and also very low humidity. These two elements will overlap at times during the afternoons/evenings causing critical fire weather conditions. This is most likely Friday and Saturday for portions of northern California and also areas east of the Cascades.

DISCUSSION

Low pressure offshore this morning will gradually eject toward the northeast over the next 24-48 hours while upper ridging persists near the Rockies. The flow aloft, which had been southerly during the past few days, is turning southwesterly, and this is allowing a much drier air mass to move in. As such, the risk of thunderstorms today is near zero with any convective activity occurring well to the north and east of the Medford CWA.

Temperatures were hot yesterday here in the valley due to strong downward transport (mixing down from 12000 feet AGL!) during the afternoon -- we managed to hit 105F at the airport, which was only one degree shy of the record (106F set in 2006/1928). Other areas didn't see the degree of mixing that we saw here in the Rogue Valley, so temps didn't get so hot -- highs of only 87F in Mount Shasta City, 90F in Klamath Falls, 93F in Roseburg, and 94F in both Montague and Alturas. Expect temps to be a bit cooler today compared to yesterday here in Medford (high of 96F), but similar readings compared to yesterday elsewhere. Marine clouds should peel back to the beaches, but may persist along the immediate coast this afternoon, then return to areas just inland tonight.

As the low ejects to the NE, mid-level SW flow will increase across the CWA. So, by Friday afternoon and evening, a well- mixed boundary layer will transport some of those stronger winds aloft down to the surface, especially east of the Cascades, but also in northern California. Expect widespread SW-W winds of 10-20 mph with peak gusts of 30-40 mph. At the same time, the surface dewpoints will crash resulting in very low humidity, in some cases, as low as 5-10% over the far east side. This will bring critical fire weather conditions and Fire Weather Watches are in effect. This pattern will persist into Saturday with a gradual shift eastward and southward of the main core of overlapping gusty winds/low RH. A smaller area of critical fire conditions could linger Sunday pm/eve over Modoc and portions of SE Klamath/Lake counties.

A broad upper trough is forecast to persist off the British Columbia coast or in the Gulf of Alaska next week with the upper ridge remaining over the Intermountain West/Four Corners. This pattern should allow winds to relax a bit early next week, but it will remain dry as any monsoonal moisture will remain cut off from the area (shunted to the southeast by prevailing SW flow aloft). Temperatures overall should be within a few degrees either side of normal, a bit lower (cooler) though nearer the coast where daily marine intrusions bring more cloud cover. -Spilde

AVIATION...23/12Z TAFs

VFR prevails across most of the CWA for the next 24 hours. This includes Medford and Klamath Falls. Some cloud cover is present this morning where thunderstorms occurred in the Cascade foothills yesterday (near and north of Crater Lake). Marine stratus (mostly MVFR, but local IFR) is also present along the coast. Think this will peel back to around the beaches this afternoon, so there may be some VFR at times then, but expect the MVFR/IFR to return tonight. Roseburg is tricky this morning. Could see brief MVFR this morning, but should become VFR by this afternoon. Local MVFR could return to Roseburg late tonight. -Spilde

MARINE...Updated 230 AM PDT Thursday, July 23, 2026

A brief period of stronger south winds and steep seas, mainly in waters beyond 10 nm from shore, is expected this morning. Otherwise, mixed seas with fresh short period northwest swell and low longer period south swell are expected through Friday. South winds switch back to northerly this weekend, but wind wave dominated seas probably hold off until early next week. -Spilde/BPN

FIRE WEATHER...Updated 230 AM PDT Thursday, July 23, 2026

A shift in the upper level pattern is expected today, which will move the region of instability/convective activity well to the north and east of our area with drier SW flow aloft winning out. As such, lightning risk will diminish to nil today, but at the expense of enhanced southwest to westerly winds during the afternoons and evenings east of the Cascades and in northern California. This is likely to overlap with low humidity, especially on Friday and Saturday. Any new fire starts would then have the ability to spread/grow quickly. Fire Weather Watches remain in place for Friday and Saturday afternoons/evenings in FWZs 624, 625, 284, and 285. We've also added FWZs 280 and 281 for Friday afternoon/evening as there should be a several hour period of gusty winds/low RH for those areas as well. Conditions will ease during the overnight period, with generally poor to moderate recoveries, poorest along the Warners of Modoc County.

The dry, diurnally breezy pattern looks to last this weekend and into early next week. But, winds should ease some and temperatures should also lower compared to earlier this week. -Spilde

MFR WATCHES/WARNINGS/ADVISORIES

OR...Fire Weather Watch from Friday afternoon through Saturday evening for ORZ624-625.

CA...Fire Weather Watch from Friday afternoon through Friday evening for CAZ280-281. Fire Weather Watch from Friday afternoon through Saturday evening for CAZ284-285.

PACIFIC COASTAL WATERS...Small Craft Advisory until 11 AM PDT this morning for PZZ370-376.