textproduct: Medford

DISCUSSION

Satellite imagery this afternoon shows quite a bit of cloud cover around the region. Marine stratus from this morning is eroding from portions of Douglas and Coos Counties. Meanwhile, an expansive cumulus field has developed east of the Cascades and over the high terrain of northern California and southwest Oregon along and south of the Rogue-Umpqua Divide. Radar shows widespread showers east of the Cascades and south into Modoc/eastern Siskiyou Counties, with some showers developing over western Siskiyou County. The lightning potential is pretty low today (10-15% chance), focused across southern Siskiyou/Modoc Counties. Convective parameters are fairly meager today, so only isolated strikes are expected today.

A shortwave trough is dropping south through the region today, just offshore, and this will help keep shower activity going on through the afternoon. Afternoon temperatures today will be near to just below seasonal normals with some fairly typical afternoon breezes (aside from some gustier winds with showers). Tonight will be much like last night. Shower activity will wane after sunset and there should be another decent marine push that brings stratus back to the coast and into the Umpqua Basin. The marine layer doesn't look quite as deep as this morning, so cloud coverage should be a bit less.

Drier conditions are expected on Tuesday. There is one more shortwave that moves through the region, but mid-level moisture decreases, and the more favorable instability moves to the south and east of the forecast area. There could be some isolated showers across southern Modoc/Siskiyou Counties Tuesday afternoon, but most areas will remain dry under partly to mostly cloudy skies. Afternoon temperatures trend warmer by around 5 to 7 degrees on Tuesday, and this warming trend continues through the remainder of the week.

Upper level ridging builds into the region Wednesday and then persists through at least Friday/Saturday. This bring a period of dry and warmer weather with high temperatures (areas inland from the coast) generally 10-15F above normal for late April/early May. This means high temperatures ranging from 75-85F (70-75F) for most inland west (east) side valleys. Coastal areas could continue to experience intrusions of late-night/morning marine stratus.

Models then show the ridge breaking down late this weekend as an upper trough just off the West Coast tries to close off offshore. An increasing number of solutions show the low closing off to our SW, which would bring an increased risk for mainly afternoon and evening showers and thunderstorms as early as Saturday afternoon, with the potential for active weather persisting Sunday into early next week. Much will depend on the eventual track of trough/low, however. Many members, particularly from the GEFS ensembles, maintain a weaker trough moving through, which would limit the overall extent/coverage of precipitation. We'll adjust the forecast as things come more into focus. -Spilde/BR-y

AVIATION...27/18Z TAFs

Onshore flow has brought MVFR ceilings and terrain obscurations to the Oregon coast and the coastal mountains, and inland into the Umpqua Valley (including Roseburg). This will slowly clear late this morning into early this afternoon between 18- 21Z.

In northern California and over the East Side, showers will return this afternoon, but coverage should be more scattered. Local MVFR/IFR conditions with terrain obstructions are possible in any heavier showers. Otherwise and elsewhere, VFR will prevail through this evening.

Additional IFR/MVFR ceilings will return to the coast and Umpqua later this evening and overnight.

MARINE...Updated 100 PM PDT Monday, April 27, 2026

North winds continue this week. Initially, winds stay below advisory speeds today. Then, gusty north winds develop on Tuesday morning south of Cape Blanco. Steep sea return by Tuesday afternoon for the waters south of Cape Blanco. North winds will likely strengthen across the waters Wednesday with very steep seas possible for the waters south of Cape Blanco and steep seas north of Cape Blanco. These conditions may linger into Thursday. Winds trend slightly lower Friday and Saturday but seas may remain steep.

MFR WATCHES/WARNINGS/ADVISORIES

OR...CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory from 11 AM Tuesday to 11 PM PDT Wednesday for PZZ350-356-370-376.

Hazardous Seas Watch from Wednesday morning through Wednesday evening for PZZ356-376.