textproduct: Medford

KEY MESSAGES

* Last day of the humid pattern with moist, southerly monsoonal flow and isolated to scattered thunderstorms. The highest risk of scattered thunderstorms today will be from the foothills of the Cascades in eastern Douglas County across the Cascades, into northern Klamath and Lake counties. Some storms will be strong with gusty winds and possible hail.

* Today will be the hottest of the next several days with highs generally 5 to 10 degrees above normal (mid 80s to mid 90s on the east side and lower 90s to 104 for west side valleys). Near or slightly below normal temperatures at the coast will reach the 60s.

* A dry pattern takes hold Thursday into the weekend. But an increase in afternoon/evening southwest to west winds is likely, especially east of the Cascades and in NE California where winds overlap very low humidity resulting in critical fire weather conditions.

DISCUSSION

The area has been wedged in between strong upper ridging over the nation's midsection and low pressure off the West Coast for the last several days. This has brought a plume of very moist, monsoonal moisture northward into the area, and it has felt more humid than usual. This will continue to be the case today with dewpoints expected to be in the upper 50s to even mid 60s west of the Cascades. High temperatures will once again be in the 90s and even lower 100s. In this type of pattern, we'd usually expect daily outbreaks of thunderstorms. But, this has been muted so far with just isolated activity, mainly due to a lack of forcing and high cloud cover ultimately reducing instability. This should change somewhat today as instability increases across the area and with the low offshore moving northward (along with the remnants of Elida), forcing for ascent should be enhanced near the Cascades in diffluent flow aloft. It will be a race though, so to speak, since models are showing drier air aloft arriving from the south and west later today and tonight. As such, we think the focus for convection this afternoon/evening will be from the Cascade foothills of eastern Douglas County across the Cascades to northern Klamath and Lake counties. Convection allowing models show this area stands a good chance at getting some cells with frequent lightning. They'll move quickly at around 20-25 mph to the NNE. With a very dry landscape, this presents critical fire weather risk, so we have a Red Flag Warning out for that. Storms that do develop could also have strong outflow wind gusts (inverted-v soundings indicate potential near or just sub-severe gusts), hail and brief heavy rainfall. While we can't rule out isolated activity farther south and west, again, the limiting factor will be the drier air moving in aloft. Expect some breezy winds to develop just about everywhere this afternoon/evening.

Once we get rid of the convection this evening, that will be it for a while. A re-orientation of the flow aloft to the southwest will bring in a much drier pattern. Models are showing a strong mid-level 500 mb jet of 45-55 kt developing Fri/Sat. This is going to cause breezy to windy conditions area wide, strongest east of the Cascades and in NE California. At the same time, massive drying will bring dewpoints way down resulting in very low humidity, in some cases, down below 10% over Modoc/Lake counties. Since there is high confidence in this pattern of overlapping strong, gusty winds and low relative humidity, we've gone ahead and issued a Fire Weather Watch for both Fri/Sat pm/eve east of the Cascades and in NE California. These conditions could persist into Sunday. Temperatures, meanwhile, should moderate a bit -- they won't be quite as hot as they are today.

Monsoonal moisture should remain well to the south and east of our area into next week due to persistent southwest flow aloft, pretty typical for late July. -Spilde

AVIATION...22/12Z TAFs

Mostly VFR is present across northern California and southern Oregon early this morning.

Marine stratus is bringing IFR/LIFR at the coast north of Cape Blanco this morning. Improvement will follow for the afternoon into early evening, with these levels expected to lift to MVFR north of Cape Blanco. However, we expect onshore flow to commence south of the Cape, so while it's VFR there now, a surge of low stratus could result in IFR there later this morning or this afternoon.

Thunderstorms are expected this afternoon, especially over eastern Douglas County as well as Lake and northern Klamath counties. Activity may also develop in Jackson, and southern Klamath, and western Siskiyou counties. These storms may be strong enough to develop small hail, lightning, locally heavy rain, and gusty, erratic winds. While the most aggressive activity is currently expected to mostly stay away from area terminals, notes of vicinity activity have been included at Medford to communicate the possible development of thunderstorm activity. -Spilde

MARINE...Updated 300 AM PDT Wednesday, July 22, 2026

Winds and seas are expected to remain below advisory levels through at least this weekend. North winds switch to southerly today as the remnants of Elida move northward offshore. Isolated showers and even a couple of thunderstorms are possible. 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

FIRE WEATHER...Updated 300 AM PDT Wednesday, July 22, 2026

Today, there is a greater concern for increased afternoon and evening thunderstorm coverage (at least in northern parts of the area) due to better instability expected and the potential for better forcing as the remnants of Elida push northward just offshore resulting in diffluent flow aloft. We think the greatest activity in terms of coverage will occur along the western slopes of the Cascades (eastern FWZs 622/617) east across the Cascades (FWZ623), and then also east of the Cascades in the typical arc from Crater Lake, across Winter Rim, and down to the Warners (FWZs 624/625). Isolated storms are also possible elsewhere across the area, including in northern California and across the valleys west of the Cascades, though a surge of drier air aloft does appear to be pushing into NorCal later in the afternoon/evening (this should keep best activity confined to areas north of the OR/CA border). Storms that do develop should be moving at a pretty good clip - in the 20-30 mph range, so while they are likely to be wetter storms with higher PWs, the faster storm motions should still raise the risk of lightning-induced fire ignitions and a Red Flag Warning is in effect.

Of note, with PW approaching or exceeding 1.50 inches, or roughly 200 percent of normal, these storms should not only be wet, but could produce heavy rain as well. Should a storm pass directly over a recent burn, such as the East Evans Creek fire, mud and debris flows are possible down any adjacent drainages.

Later this week (Thursday/Friday), eastward movement in the upper level pattern is likely, which is likely to shift the region of instability east of our area with drier SW flow aloft winning out. As such, lightning risk will diminish to almost nil, but at the expense of enhanced westerly winds during the afternoons and evenings east of the Cascades, which could overlap with low humidity. Any new fire starts would then have the ability to spread/grow quickly. We have gone ahead and issued a Fire Weather Watch for Friday and Saturday afternoons/evenings in FWZs 624, 625, 284, and 285.

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

MFR WATCHES/WARNINGS/ADVISORIES

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

Red Flag Warning from 11 AM this morning to 11 PM PDT this evening for ORZ617-622>625.

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

PACIFIC COASTAL WATERS...None.