textproduct: Medford

DISCUSSION

Wind gusts really didn't pan out today, especially in the valleys this afternoon as weak mixing didn't allow much momentum transfer. However, some of our windier locations at elevation did reach wind advisory criteria and the Shasta Valley was blustery as usual with Montague reporting a wind gust of 59mph during the cyclogenesis this morning.

In any case, the low is weakening and moving a bit farther to the north and west this afternoon and winds will continue to die down into the evening hours. Winter weather is the only remaining concern as this low ends up rotating back into the northern California coast by Friday morning. The biggest concern remains south of the Shasta Valley near Mt. Shasta City. Heavy snow will likely fall there tonight as high resolution guidance shows 6 to 8 inches on the valley floor around Mt. Shasta City up to Weed and nothing north of Weed. The probability of 1" of snow per hour is about 50%, and we usually see impacts when these 1" snow fall rates persist for a few hours. Expect some delays in travel tonight as the strong southerly winds enhance orographic lift over this relatively cold air.

The Cascades and Siskiyou Mountains will also see some snow accumulation once this low rotates into the forecast area later tonight. Snowfall rates should pick up around this time with snow levels down to 4000 feet across most of the forecast area, except around Mt. Shasta City where snow levels will fall down to 3300 feet under the heavier snow.

Eventually, this low will weaken further and push into the forecast area late Friday afternoon. Impacts remain moderate to low around this time as snow continues to accumulate, although the rates are falling off around this time, except the higher terrain in California. Eventually by Friday night, the trough axis will push further east and high pressure will begin to build in the wake of this low. One has to think valley fog will be in the cards and some of it could be thick given all the surface moisture.

Temperatures will be well below freezing Friday night and Saturday night, so freezing fog is more likely across the forecast area. Extreme cold on our graphical hazardous weather outlook is only showing limited risk in these colder temperatures. For perspective, our average low in Medford this time is 37 and we're forecasting lows in the mid 20's here Saturday night, so only 10 degrees below normal for this time of year, which isn't bad.

Overall, we'll close out 2025 with fairly quiet weather. The NBM is picking up on some probability of precipitation around the New Year. -Smith

AVIATION...25/18Z TAFs

VFR levels are generally present across northern California and southern Oregon at the start of the TAF period. Continuing rain and periodic snow showers around Mount Shasta are causing local IFR/LIFR conditions, and a line of stronger rain/snow showers is passing through Klamath Falls this morning.

Showers are expected to continue through the TAF period across the area, with most of the activity over northern California. Snow levels decreasing to 3500-4000 feet today into Friday may bring snow showers over terrain and across the east side. Both rain and snow showers can cause locally lower ceilings and visibilities as well as obscure elevated terrain. Gusty winds are expected through this afternoon, especially in the Shasta Valley and across the east side. Low level wind shear may be present across most of the area through this morning, then lingering over coastal areas and higher terrain into Friday morning. -TAD/-9

MARINE...Updated 200 PM PST Thursday, December 25, 2025

South to southeast gales (30-40 kt with gusts to 50 kt) and very steep seas between 13 to 23 ft continue in all waters through this evening. Locally storm force gusts are possible through this afternoon. Guidance indicates a 35-45% chance for storm force gusts for the waters with in 20 nm of shore between Gold Beach and Cape Blanco and a 20% chance for storm force gusts for other areas. With this frontal system, there is also a 20% chance for thunderstorms over the waters through Friday morning. The highest chance will be found south near Brookings.

As the low pressure moves east over the waters tonight and Friday morning, expect continued areas of gales for the waters from Cape Blanco south. Winds will shift from south to northwest as this low moves through Friday morning. Very steep seas will persist across all the waters through Friday morning. Gusty north winds (20-30 mph with gusts up to 35 mph) are expected to develop Friday afternoon and evening with steep seas in all waters through Saturday afternoon.

The overall weather pattern looks to settle down later in the weekend and is expected to continue through early next week. Overall light to moderate north winds will be found with areas of gusty north winds and steep seas south of Cape Blanco.

MFR WATCHES/WARNINGS/ADVISORIES

OR...Wind Advisory until 4 PM PST this afternoon for ORZ023>026- 029>031.

Winter Weather Advisory until 10 PM PST Friday for ORZ027-028.

CA...Winter Storm Warning until 4 PM PST Friday for CAZ080-082-083- 085.

Wind Advisory until 4 PM PST this afternoon for CAZ080-081- 083>085.

PACIFIC COASTAL WATERS...Gale Warning until 10 AM PST Friday for PZZ350-356-370-376.

Small Craft Advisory from 10 AM to 10 PM PST Friday for PZZ350- 356-370-376.

Hazardous Seas Warning from 10 PM this evening to 10 AM PST Friday for PZZ350-370.