textproduct: Medford

KEY MESSAGES

* The air mass remains unusually dry today, but an increase of high clouds late today will be the first sign of a change.

* Smoke will persist for Jackson, Klamath, and Siskiyou counties, with some temporary afternoon into early evening improvement expected for Klamath and Siskiyou counties. Also, an influx of smoke into Lake County today from fires in central Oregon.

* Thunderstorms re-enter the forecast beginning Monday, mainly for the Cascades and east side. The highest risk will be on Tuesday and Wednesday, including lesser chances for areas west of the Cascades.

* Remaining hot inland during the next week 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). Meantime, near or slightly below normal temperatures at the coast will reach the 60s.

DISCUSSION

Our weather pattern for the next week will continue to be characterized by low pressure over the eastern Pacific and ridging centered well inland. The low that had a large influence in bringing gusty late day winds over the past few days has now moved northeast into British Columbia, leaving a more typical pressure gradient/weaker winds inland this afternoon. It will also result in a greater influence of the ridge with a further 2 or 3 degrees of warming anticipated today, compared to yesterday.

Late today into tonight and continuing into Monday, a plume of monsoonal moisture aloft will bring high clouds into the area. This could generate a few showers, mainly over the higher terrain, but most of any showers will evaporate before reaching the ground. Weak instability with shortwave disturbances could produce a couple of lightning strikes tonight into Monday morning. But, of greater certainty is that on Monday afternoon a few thunderstorms will be focused on the Crater Lake region of the Cascades into northern Klamath County.

On Tuesday into Wednesday, stronger southerly flow aloft is expected between a trough offshore tracking northward and the persistent ridge over the Great Basin. There is still a modest amount of uncertainty in the convective forecast, with still some possibility of scattered thunderstorm coverage of a broad portion of our area, to include portions of the west side. But, the highest probability is for isolated coverage on both days...focused east of the Cascades. It would be of note that the storms look to trend wetter over time. Though the highest precipitable water values are likely east of our area, with values at around 200% of normal, this could cause some significant rain in thunderstorms.

The region of greatest instability looks to shift northeastward on Thursday, possibly lingering into northern and/or eastern portions of the east side. For Friday into next weekend, a shift to an onshore flow pattern is likely with a more stable, dry air mass.

AVIATION...19/12Z TAFs

VFR will mostly prevail across inland areas through the TAF period. One exception will be impacts from wildfire smoke that will bring periods of MVFR visibilities and/or ceilings to the Rogue Valley, Klamath Basin, and Shasta Valley including Medford, Klamath Falls, and Montague. Smoke from central Oregon fires will also impact Lake County, including Lakeview.

Along the coast, LIFR ceilings and visibilities are expected to persist through mid-morning, around 16Z-18Z. Conditions are forecast to improve to VFR for the afternoon, then LIFR returns around 03Z this evening into Monday morning.

MARINE...Updated 200 AM PDT Sunday, July 19, 2026

Gusty north winds will continue with steep seas to very steep seas through this evening. The strongest winds and very steep seas are expected from Port Orford south beyond 5 nm from shore. Steep, short period seas and areas of gusty winds will linger across the waters later tonight into Monday evening. Seas will transition on Monday from wave dominated to fresh swell. Conditions gradually improve late Monday through Tuesday into Wednesday, with below advisory conditions. Northwest swell dominated seas may increase slightly late in the week.

FIRE WEATHER...Updated 200 AM PDT Sunday, July 19, 2026

There is an overall increase in confidence in the forecast, but the story for the next week is largely consistent with the inherited forecast.

The three main aspects of the fire weather forecast for the next week are: first, the extent of hot, dry, and breezy/windy conditions, second, the potential risk and coverage of thunderstorms during Monday through Thursday, and lastly, a likely transition to dry and slightly cooler weather late next week that would be accompanied by stronger than normal east side westerly winds.

The weak trend toward not quite so extreme dryness and normal strength of afternoon breezes will continue today. This slight moistening of the air mass today will be accompanied by a late day increase of high clouds, and perhaps some east side cumulus buildups.

As has been advertised, with relatively warm air aloft limiting the extend of instability, and high elevation of the moisture plume, it still looks like the main result of an influx of monsoonal moisture from late this afternoon through tonight into Monday morning will be to produce a thick blanket of cirrus. Radar returns are expected to be mostly virga, with the higher terrain having the best chance of isolated light showers reaching the ground. The probability of showers will be highest during Monday morning. Given the arrival of shortwave disturbances over our area in the southerly flow between the trough offshore and Great Basin centered ridge, it is not out of the question for a few lightning strikes to occur with weak, short- lived thunderstorms. A 5%-10% probability of thunderstorms is forecast for late tonight into Monday morning, in line with the NBM and SREF.

By Monday afternoon, and into Monday evening, instability still looks to be weak but sufficient for a slight chance mention of thunderstorms at least for northern Klamath County, possibly extending both into northern Lake County and southward across the remainder of Klamath County to the vicinity of the Siskiyou/Modoc County border. Then, on Tuesday and Wednesday, there is a greater concern for increased afternoon and evening thunderstorm coverage. At least isolated activity is expected to be focused east of the Cascades and near Crater Lake, while there is less of a model consensus on whether activity will also extend farther southwest to the remainder of our Cascades and possibly the Interstate-5 corridor. Also to be mentioned is that there is the possibility that with the modified tropical moisture influx in addition to the monsoonal influx of moisture, these storms will become wetter over time.

Late in the 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. But, a plausible, slower solution would keep instability and some slight thunderstorm risk over the east side on Thursday. The bigger impact late in the week into next weekend would be the risk of enhanced westerly winds occurring during the afternoons and evenings east of the Cascades.

MFR WATCHES/WARNINGS/ADVISORIES

OR...CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 8 PM PDT Monday for PZZ356-376.

Small Craft Advisory until 5 PM PDT Monday for PZZ350-370.

Hazardous Seas Warning until 11 PM PDT this evening for PZZ356- 376.