textproduct: Medford

KEY MESSAGES

DISCUSSION

AVIATION (06Z TAFs)

Not expecting much relief along and near the coast tonight, so expecting MVFR/IFR conditions to persist for KOTH through tomorrow. There could be some relief (brief VFR) at KOTH through the afternoon hours, but confidence was not high enough on timing to include at this time. The marine push may be far enough inland to impact KRBG, and confidence was high enough (70%) to include MVFR ceilings overnight through Thursday morning. Otherwise, expecting VFR conditions for both KMFR and KLMT through this cycle, with typical diurnal breezes for all terminals.

-Guerrero

MARINE

.New Aviation Section

AVIATION (00Z TAFs)...

Not expecting too much relief along and near the coast today/tonight, so expecting MVFR/IFR conditions to persist for KOTH overnight and through tomorrow. The marine push may come far enough inland to impact KRBG, and confidence was high enough (50%) to include MVFR ceilings overnight through Thursday morning. Otherwise, expecting VFR conditions for both KMFR and KLMT through this cycle, with typical diurnal breezes (enhanced at times) for all terminals. There is a caveat here; we will need to monitor thunderstorm potential (10-15%) near KMFR through ~8pm, but at this time confidence was not enough to include a mention.

-Guerrero

PREV DISCUSSION... /Issued 114 PM PDT Wed Jul 22 2026/

KEY MESSAGES...

* Today will be last day of the humid pattern with moist, southerly monsoonal flow and isolated to scattered thunderstorms. Highest risk of scattered thunderstorms today will be from the Cascade foothills 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 day 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. An increase in afternoon/evening southwest to west winds is likely, especially east of the Cascades and in NE California where strong winds overlap with very low humidity resulting in critical fire weather conditions Friday and Saturday.

DISCUSSION...The area has been wedged between strong upper ridging over the nation's midsection and low pressure off the West Coast for the last several days, which has brought a plume of very moist, monsoonal moisture into the area. With dewpoints expected to be in the upper 50s to even mid 60s west of the Cascades, it'll be another humid day with high temperatures again in the 90s and even lower 100s today. In this type of pattern, we 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 will 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 today and tonight.

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, around 20-25 mph to the NNE, and with a very dry landscape, this presents a 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. The Storm Prediction Center (SPC) does have portions of our region in a Marginal Risk for severe weather today, meaning there's a 2%-5% chance for any storm to become severe within 25 miles of any location within the designated area. The highlighted area is mainly from Crater Lake northward along the Cascades and eastward across northern Klamath/Lake counties. 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. There is high confidence in this pattern of overlapping strong, gusty winds and low relative humidity, and a Fire Weather Watch is in place for both Fri/Sat pm/eve east of the Cascades and in NE California. These conditions could persist into Sunday, but confidence was not high enough to include Sunday in the watch at this time. Temperatures, meanwhile, should moderate a bit Thursday and Friday, cooling by about 5 to 10 degrees west of the Cascades. Temperatures will even return to near to just below seasonal normals by the end of the weekend and into early next week. Monsoonal moisture should remain well to the south and east of our area into next week due to persistent southwest flow aloft, which is pretty typical for late July.

AVIATION...22/18Z TAFs...Mostly VFR is present across northern California and southern Oregon early this morning.

Marine stratus has burned back from most of the coast, but remains present in the offshore waters. We expect onshore flow to commence as the day goes on, so it is possible that a surge of low stratus could result in IFR there this afternoon. A stronger marine push tonight will result in IFR conditions along the coast and into the Umpqua Basin overnight tonight.

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/BPN

MARINE...Updated 100 PM PDT Wednesday, July 22, 2026...As tropical remains move north through the southern Oregon coastal waters tonight into early Thursday morning, there will be a brief period of stronger south winds and steep seas, mainly in waters beyond 10 nm from shore. 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 100 PM 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 still raises 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 by Thursday, but at the expense of enhanced southwest to westerly winds during the afternoons and evenings east of the Cascades, which could overlap with low humidity, especially on Friday and Saturday. Any new fire starts would then have the ability to spread/grow quickly. A Fire Weather Watch is in place for this for Friday and Saturday afternoons/evenings in FWZs 624, 625, 284, and 285. 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, temperatures should also lower some compared to earlier this week.

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 Saturday evening for CAZ284-285.

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