Area Forecast Discussion

DISCUSSION

Updated marine and aviation discussions.

AVIATION...19/18Z TAFs

VFR conditions will prevail through most of tonight with lowering and thickening clouds as low pressure offshore edges eastward. Expect gusty southerly winds this afternoon, especially in the Shasta Valley and over the East Side. Even the Rogue Valley, including Medford, will get breezy. Wind shear doesn't appear to be a high risk at this time, but mountain wave turbulence in Siskiyou County is likely. Precipitation chances remain low at the coast through tonight, but some light rain and lower ceilings could impact the marine waters. Eventually, higher rain chances and lowering ceilings (to MVFR) move onto the coast either late tonight or Monday morning. We expect an uptick in winds again later Monday morning into the afternoon for similar locations (Shasta Valley, Medford and the East Side). Increasing southerly flow into Siskiyou County, including the Mt Shasta region, will cause lowering ceilings (to MVFR) there as well Monday afternoon along with rain and high elevation snow (above 5000 feet). Precipitation will be more showery north of the Siskiyous. -Spilde

MARINE...Updated 100 PM PDT Sunday, April 19, 2026

Low pressure offshore will bring a period of active weather tonight through Monday, with periods of gusty south winds and elevated seas/swell. Winds are likely to be strongest through Monday evening with a period of steep seas hazardous to small craft mostly beyond 10 NM from shore. Conditions should improve Tuesday as the low gradually pushes into Northern California. Then, increasing NW swell follows Wednesday into Thursday with a return of north to northwest winds. -Spilde

PREV DISCUSSION

/Issued 659 AM PDT Sun Apr 19 2026/

DISCUSSION...

Key Points:

* Breezy winds today through Wednesday on the west side, and through Thursday on the east side. Strongest winds on Monday afternoon, including Advisory strength gusts up to 50 mph in the Shasta Valley * Warm, well above normal temperatures today, at similar levels to yesterday but with increasing high clouds * Low pressure affects the region for much of the week - Rain chances start at the coast this evening. Precipitation spreads inland to the Cascades Monday and continues across the area Monday night through Wednesday - Higher elevation snow mainly Tuesday night into Wednesday with snow levels 6500 feet lowering to 5000 feet - Isolated thunderstorms possible Tuesday and Wednesday, mainly from the Coast Range to the Cascades during Tuesday afternoon - Lingering low level moisture Wednesday night into Thursday morning with light showers possible on the west side * Drying trend Thursday into next weekend with slightly cooler than normal lows and warm afternoon highs Further Details:

Precipitation looks to start at the southern Oregon coast as early as this evening. But, it will be focused south of our area, upon the Sierra Nevada, Monday night into Wednesday. A beneficial light rain is expected for our area with snow on the higher peaks. Snowfall of 3 to 6 inches is forecast for the Cascades, but 4 to 8 inches for the Warner Mountains, and as much as a foot for the higher terrain of far southern Siskiyou County into the Trinity Alps. In total, rainfall of a quarter of an inch to an inch should be common for the event on the west side and around 0.15 inches to a half inch on the east side.

Of arguably larger impact, southerly winds will trend stronger this afternoon and reach a stronger peak again on Monday afternoon. A Wind Advisory /PDXNPWMFR/ has been issued for the Shasta Valley for Monday, with gusts up to 50 mph expected. Also during Monday, south winds will approach the lower end of Advisory criteria in the Rogue Valley with some of the high resolution short term model data indicating peak sustained speeds of 25 mph and gusts up to 40 mph. Southwest to northwest winds will be breezy, remaining stronger than typical for the day-time hours Tuesday through Wednesday on the west side and Tuesday through Thursday on the east side.

The thunderstorm risk looks to reach a peak, but with not more than isolated activity, during Tuesday afternoon from western Siskiyou County into southwest Oregon. Instability lingers with shortwaves rotating around the back side of the trough on Wednesday, but looks to be just a 5% to 10% probability.

Models have trended drier for the Thursday through Sunday period, with a ridge building in from the coast and troughing shifting to the Rockies for only slight chances of continued showers, mainly on the east side.

AVIATION...19/12Z TAFs...VFR conditions will prevail for the next 24 hours with thickening high clouds and generally light winds early this morning. Southerly winds become gusty this afternoon, especially in the Shasta Valley and over the East Side. Even the Rogue Valley, including Medford, will get breezy. Precipitation chances remain low at the coast today. However, some light rain and lower ceilings could impact the marine waters. Eventually, higher rain chances and lowering ceilings move onto the coast tonight into Monday morning. -Spilde/DW

MARINE...Updated 230 AM PDT Sunday, April 19, 2026...Seas are at a minimum early this morning. Low pressure offshore will bring a return of active weather today into Wednesday, with increasing swell and periods of gusty south winds. Winds are likely to be strongest from late this morning through Monday evening with a period of steep seas hazardous to small craft mostly beyond 10 NM from shore. Conditions should improve a bit Tuesday, then increasing NW swell should bring an increase in seas again Wednesday into Thursday. -Spilde/DW

MFR WATCHES / WARNINGS / ADVISORIES

OR...None.

CA...Wind Advisory from 8 AM to 6 PM PDT Monday for CAZ081.

PACIFIC COASTAL WATERS...Small Craft Advisory until 8 PM PDT Monday for PZZ370-376.