EUGENE, Ore. -- After days of clouds due to onshore flow from a strong upper level low off the coast, that low is now moving ashore. It brought drizzle this morning and will increase instability in the atmosphere this afternoon, sparking thunderstorms.
Storms will be beginning to fire up in the Cascades around 2 to 3 p.m. and intensify into the early evening.
Friday: Mostly cloudy w/ chance of PM showers and storms. Highs in upper 70s
Saturday: Mostly cloudy w/ chance of showers and storms. Highs in mid 70s
Sunday: Sunny. Highs in low to mid 80s
Monday: Sunny. Highs in mid to upper 80s
Tuesday: Sunny. Highs in mid to upper 80s
Wednesday: Sunny. Highs in mid 80s
Thursday: Mostly sunny. Highs in low 80s
Models then point those storms drifting into the I-5 Corridor closer to 7 to 8 p.m. This means if you live in the Valleys, it will be important to be weather aware this evening.
Overnight storms will quiet down and fizzle out, but storms will fire back up in the later portion of Saturday morning in eastern Lane and Douglas counties.
On Saturday afternoon, expect isolated showers and storms to be mainly focused from I-5 east through the Cascades. The Coast will likely remain rather dry today and tomorrow.
The Severe Prediction Center, SPC, in Norman, Oklahoma, placed a “2 Slight Risk” across portions of the Foothills, Cascades, and central Oregon. The SPC ranks severe risk on a scale 1 to 5, 1 being marginal and 5 being high. For example, 5 High Risk would be a major tornado outbreak and something you would see in the Great Plains. Friday’s risk will be a 2 out of 5 risk.
The atmosphere in Western Oregon will be ripe for storms. This is due to the upper level low providing spin and convective energy. Convective energy or CAPE (Convective Available Potential Energy) in the most basic way tells us where thunderstorms are likely to form. The greater the energy the more likely storm storms will form in that area. Our highest CAPE will be in Foothills of Lane and Douglas counties. That is where we are most likely to see severe storms.
Our biggest severe threats today will be abundant lightning, large hail from rotating updraft thunderstorms, and strong winds near thunderstorms. Lightning is a big concern at this time due to us being in the middle of fire season. This has led to a Red Flag Warning in the Umpqua Basin from 11 a.m. to 5 p.m. on Saturday.
The Red Flag Warning means the conditions are favorable for large fire growth. This is due to abundant lightning over dry fuels causing the possibility for numerous new wildfire starts that could overwhelm initial attack resources. However, it will likely be wet under the core of these storms, which will help decrease the danger. The warning is also for the possibility of erratic winds near thunderstorms that could lead to increased growth if said fires are sparked.
Despite high risk of severe weather and enhanced wildfire risk, these storms could bring a decent shot of moisture to locations under the core of thunderstorms. This means not everyone will see moisture. Models currently have the majority of moisture focused the eastern half of our viewing area, with some locations possibly seeing as much as an inch between Friday and Saturday.
More stable air will move in Sunday into next week, bringing sunshine back to the region.
For more weather information, go to the KEZI 9 News StormTracker 9 weather page.