textproduct: Medford

KEY MESSAGES

* Today and Wednesday 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 103 for west side valleys). Near or slightly below normal temperatures at the coast will reach the 60s.

* Isolated light showers this morning, especially in Modoc/Lake counties will give way to isolated thunderstorms this afternoon/evening. Highest risk is in the Cascades north of Crater Lake, but can occur anywhere from the mountains of western Siskiyou County up the Cascades, over to Winter Rim and the Warner mountains.

* The highest risk of thunderstorms for the area will be on Wednesday (could reach scattered coverage Cascades/Foothills eastward), including lesser chances for areas west of the Cascades. Some storms will be strong with gusty winds and possible hail. Best chance for this is up the Cascades into the Douglas County foothills and over to NW Klamath County.

* A drier pattern takes hold late week, but probably with an increase in afternoon/evening breezes, especially east of the Cascades.

DISCUSSION

The forecast area remains wedged in between a strong ridge over the nation's mid section/Rockies and low pressure off the California coast (including tropical remnants). Monsoonal moisture continues to stream northward into the area and is generating a few light showers from Modoc into Lake County this morning. This flow pattern hasn't allowed things to cool off as readily at night, as evidenced by the daily record highest minimum set here at Medford yesterday morning (71F). The record was 68F set in 2023. It's a little cooler than it was at this time yesterday morning, but still warmer than usual (70F). We're still expecting some high-mid level clouds today. Even so, we should see at least a thinning of the high cloud cover, so some instability could generate isolated thunderstorms, mainly near or just north of Crater Lake in the Cascades and southeastward down to around the Warners during the afternoon/evening.

Wednesday, stronger southerly flow aloft is expected between the trough offshore tracking northward (including the remnants of Tropical Storm Elida) and the persistent ridge over the Great Basin/Rockies. There is still a modest amount of uncertainty in the convective forecast (especially with areal extent), but there is a decent chance of scattered thunderstorm coverage over a broad portion of our area, to include areas from the Cascades eastward and also portions of the west side (most likely Douglas County east of Roseburg, but also the Siskiyous and western foothills of the Cascades south and east of the Rogue Valley). Farther south and west, coverage should be more isolated or non- existent (coast). Storms do look to trend wetter over time with highest precipitable water values at around 200% of normal (perhaps near or above 1.50 inches). While a widespread severe weather outbreak is not likely, a stronger cell or two could produce strong, gusty winds and hail. This appears most likely over the Cascades near/north of Crater Lake, the eastern Douglas Foothills and also NW Klamath County. Generally, any storms that develop Wednesday will move to the north to northeast, contain frequent lightning, small hail, and gusty winds, and could produce periods of heavy rainfall.

The region of greatest instability looks to shift northeastward out of the area Thursday with a shift to an onshore flow pattern Friday into this weekend. The result will be a more stable, dry air mass, but along with enhanced afternoon and evening winds. This will be the case here in the Rogue Valley, but also especially for areas east of the Cascade. -Spilde/BPN

AVIATION...21/12Z TAFs

LIFR will persist at the coast this morning. Patchy LIFR will then linger north of Cape Blanco through late afternoon before widespread LIFR returns this evening.

Areas of mid-level and mostly high-level clouds will continue to produce VFR ceilings over portions of northern California and southern Oregon today. These clouds could produce a few light showers or virga, mainly over Modoc and Lake counties, including Lakeview. By this afternoon and evening, cumulus buildups are expected with a slight chance of thunderstorms in western and central Siskiyou County, also north and northeastward along the Cascades and across much of south central Oregon. There is a slight chance of wildfire smoke affecting the Medford and Klamath Falls terminals. -Spilde

MARINE...Updated 200 AM PDT Tuesday, July 21, 2026

Winds and seas are expected to remain below advisory levels through at least this weekend. North winds today switch to southerly Wednesday 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 230 AM PDT Tuesday, July 21, 2026

A large upper ridge remains centered over the Great Basin/Rockies and into the southern Plains, while low pressure is off the California coast. Southerly flow aloft continues to bring a broad moist plume northward across much of the West and this is resulting a swaths of mid-high level clouds across NW Nevada, northern California and into south-central/SW Oregon. We are seeing another thicker area of clouds this morning across NE California, and this is bringing some scattered light showers from Modoc into Lake County at this time. Isolated showers are also moving up from Trinity County into western Siskiyou County. Most of these are aloft, but some could reach the surface, especially over the higher terrain. The cloud cover won't be quite as thick (or persistent) as it was yesterday and this should allow temps today to be near or several degrees higher than yesterday. As such, the atmosphere should destabilize a bit better today. By this afternoon and evening, cumulus buildups are expected with a slight chance of thunderstorms in western and central Siskiyou County, also north and northeastward along the Cascades and across much of south central Oregon and also Modoc County in NE Cal. Coverage of lightning doesn't appear to be very high (mainly isolated), so despite the lightning risk, we aren't planning any red flag warnings for today.

On Wednesday, there is a greater concern for increased afternoon and evening thunderstorm coverage. This is due to better instability expected in advance of moisture arriving in southerly flow aloft at peak heating along with the potential for better forcing as the remnants of Elida push northward offshore. We think the greatest activity in terms of coverage will occur from the Siskiyous and western slopes of the Cascades (FWZ 621, and eastern 622/617) east across the Cascades (FWZ623), and then also east of the Cascades in the typical arc (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. We have maintained the fire weather watch for this shift, but since guidance hasn't changed much, there's a good chance this will be upgraded later today.

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'll continue to monitor this potential and consider potential wind/low RH headlines.

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 Wednesday morning through Wednesday evening for ORZ617-621>625.

CA...PACIFIC COASTAL WATERS...None.