textproduct: Medford

DISCUSSION

KEY MESSAGE 1...A Freeze Warning is in effect through 9 AM PDT for the valleys of eastern Curry, Josephine, Jackson, and western Siskiyou County. Also, a Frost Advisory for Coos and Douglas County valleys. The cooling overnight has been aided by clear to mostly clear skies. A gradual increase of high clouds is expected today, while patchy valley low clouds in portions of Coos and Douglas counties dissipate after sunrise. High pressure will strengthen over our area today into Saturday, then continue to build as it shifts toward the Great Basin and Rockies on Sunday.

KEY MESSAGE 2...Both southerly flow and moisture aloft will strengthen Saturday night into Sunday with thicker high clouds expected. The main effect of the approaching upper level closed low will be an increase in south to southwest winds for the Shasta Valley and the east side. The strongest winds (gusts up to 45 mph) are expected in the southern Shasta Valley near Weed during Sunday afternoon, secondarily in Lake County near Summer Lake and Silver Lake on Monday and Tuesday (gusts up to 35 mph).

KEY MESSAGE 3...The downslope flow on Sunday (and possibly through Tuesday) will very likely keep the Shasta and Rogue valleys dry, but a few sprinkles can't be completely ruled out from the coast to the Cascades. Even at the coast, a relatively dry lower atmosphere should keep things mainly dry into Sunday evening. The probability of showers will trend higher later Sunday night into Wednesday, with ensemble data showing a wider spread in solutions but also higher average precipitation amounts Tuesday night into Wednesday. The probability of thunderstorms will be highest during Monday and Tuesday in the late afternoons, but it is too soon to tell what portions of our area will be favored for activity.

KEY MESSAGE 4...Compared to conditions Sunday through Tuesday...on the back side of the low, during Wednesday into Thursday, the scenario flips with a saturated lower portion of the airmass in a noticeably cooler west to northwest flow for a higher probability of more uniformly light showers. This new low is likely to track southward with a gradually diminishing probability of showers and gradually warming temperatures late next week.

AVIATION...17/12Z TAFs

VFR conditions early this morning will continue into Saturday morning, with the exception of patchy IFR that has developed in the Coquille and lower Umpqua valleys and may briefly extend to both Roseburg and North Bend around sunrise. This IFR in Coos and Douglas counties is expected to improve to VFR after 15Z this morning. A similar scenario of patchy southwest Oregon valley IFR is likely for early Saturday morning.

MARINE...Updated 200 AM PDT Friday, April 17, 2026

A weak thermal trough will maintain gusty north winds and steep seas south of Cape Blanco today into early Saturday morning. Low pressure offshore will bring a return of active weather Sunday into Wednesday, with increasing swell and periods of gusty south winds. Winds are likely to be strongest from Sunday morning through Monday evening, with steep seas possible.

MFR WATCHES/WARNINGS/ADVISORIES

OR...Freeze Warning until 9 AM PDT this morning for ORZ024-026.

Frost Advisory until 9 AM PDT this morning for ORZ021-023.

CA...Freeze Warning until 9 AM PDT this morning for CAZ080.

PACIFIC COASTAL WATERS...Small Craft Advisory until 2 AM PDT Saturday for PZZ356-376.