textproduct: Medford

KEY MESSAGES

* Very low(<5%) chance of a thunderstorm around Lake and Klamath Counties Thursday.

* Temperatures warm up on Friday.

* Dry cold front stalls out over southern Oregon on Saturday with winds trending higher and cooler temperatures in some areas.

* Temperatures heat up Monday and Tuesday with moderate heat risk in valleys west of the Cascades.

DISCUSSION

Another strong marine push has brought low clouds to the coast and the Umpqua Basin this morning. These clouds should burn off through the late morning, but should help to keep today's temperatures just a slight bit cooler. Otherwise, another warm and dry day is in store for southern Oregon and far northern California, in an near repeat of yesterday. This includes the daily push of smoke from the Castle Fire east in the afternoon and evening before settling and draining down the Cascade foothills in Douglas County in the evening/overnight, and the smoke from the central Oregon fires settling into portions of Klamath and Lake counties through the morning.

Another short wave is anticipated to traverse the west to southwest flow overhead this afternoon. Most models, including the CAMS, show very little to no convective development this afternoon, but a few of the synoptic ensemble members hint at something. Given the dry atmosphere (PWATs of around half an inch), and a rather strong mid-level cap, it is highly doubtful that the shortwave will be able to induce and convection. Overall, the chances of a weak shower or isolated thunderstorm remain under 5% in northern Lake and Klamath Counties Thursday afternoon; not enough to mention in the forecast products.

High temperatures trend warmer by around 5 degrees on Friday as a warmer air mass under the massive southwest US ridge nudges into the region on the back side of the departing shortwave. Then, a dry cold front pushes into the region Saturday as the northeast Pacific trough moves onshore into BC and Washington state. The front weakens considerably and begins to stall as it crosses our forecast area. As a result, temperatures on Saturday will be around 10 degrees lower than Friday's highs for areas west of the Cascades, but there will little to no difference to the east (although there should be some slight cooling east of the Cascades on Sunday once the front finally limps through). Also, some gusty winds will accompany the front Saturday, with peak afternoon/evening gusts of 20 to 30 mph across the region.

With all this colder air moving in behind the front, the extreme forecast index(EFI) was picking up on unusually cold temperatures Saturday night with EFI values around -0.6 to -0.8 for late July. We are forecasting some lows in the mid 30's around Chemult and perhaps sub freezing temperatures south of Chemult in the Klamath Marsh area. The cooler than normal temperatures will continue through the weekend as an upper level wave progresses through the Pacific Northwest. However, this colder air will be short lived.

Some upper level energy from the aforementioned wave will swing through Washington Sunday night with another dry cold front flying down the Oregon coast. Pressure gradients help kick off a thermal trough and temperatures warm up west of the Cascades Monday afternoon as high pressure builds. That thermal trough will linger into Tuesday and perhaps Wednesday as Medford is expected to hit 100 degrees on both days. Both the ECMWF and GFS want to push the thermal trough eastwards towards the end of Wednesday, so we'll see if we can get some stronger onshore flow towards the end of next week.

AVIATION...30/12Z TAFs

MVFR/IFR in stratus along the coast and in the Umpqua Basin, including at Roseburg, will persist through much of the morning, before clearing to VFR by late morning to midday. Low flight conditions are likely to return late this evening and tonight.

Elsewhere, VFR levels will prevail with clear skies and normal diurnal breezes throughout the next 24 hours.

MARINE...Updated 130 AM PDT Thursday, July 30, 2026

North winds ease a bit today, with seas diminishing to around 5 ft. These conditions will persist through Friday, then a low pressure system passing to the north will produce very strong northerly winds through the weekend and into early next week, as it tightens the gradient and enhances the thermal trough to the south. As a result, gales and very steep seas are highly likely Sunday into Monday south of Cape Blanco, and periods of storm force gusts possible. Gusty winds and steep seas are expected north of Cape Blanco. -BPN

FIRE WEATHER...Updated 200 AM PDT Thursday, July 30, 2026

Overall, warm and dry conditions continue. Very slight chances (less than 5%) remain for afternoon/evening dry thunderstorms east of the Cascades today. Friday looks to be the warmest day of the week, with temperatures about 5 degrees above normal before cooling to about 5 degrees below normal over the weekend.

The main fire weather concern will be the passage of a dry cold front Saturday. As with most dry fronts this time of year, gusty winds are expected to accompany its passage, with gusts up to 20 mph expected west of the Cascades, and of 25 to 35 mph to the east. While the front will bring some slightly improved humidities to the area, conditions will be very close to critical values for some locations, particularly the high terrain and typically windier areas of Lake and Modoc counties. This period will be watched closely, and fire weather headlines may be necessary should models dry slightly or winds increase slightly from the current forecast. -BPN

MFR WATCHES/WARNINGS/ADVISORIES

OR...None.

CA...None.

PACIFIC COASTAL WATERS...None.