Medford, Ore. – Residents across southern Oregon and northern California should prepare for increasing afternoon and evening thunderstorm chances this week as monsoonal moisture spreads into the region, bringing the potential for lightning, locally heavy rainfall and isolated strong storms by midweek.
According to the National Weather Service in Medford, thunderstorm chances will begin Monday with 5% to 10% probabilities along and east of the Cascade Range. Storm coverage is expected to expand by Wednesday, when chances increase to 20% to 25% east of the Cascades. A 5% to 10% chance of isolated thunderstorms also exists west of the Cascades on Tuesday and Wednesday.
Communities including Klamath Falls, Lakeview, Alturas, Summer Lake and other areas east of the Cascades have the highest likelihood of thunderstorms. While widespread severe weather is not anticipated, forecasters say increased atmospheric moisture on Wednesday could support locally heavy rainfall and an isolated severe storm.
Lightning will be a concern for anyone spending time outdoors, particularly in the mountains, open fields and near lakes. Residents and visitors should have a plan to seek shelter immediately if thunderstorms develop. Remember, when thunder roars, go indoors. Wait at least 30 minutes after the last rumble of thunder before resuming outdoor activities.
Forecast confidence is highest for increasing thunderstorm coverage by Wednesday, though the exact location of the strongest storms remains uncertain. Additional weather statements or advisories may be issued if the threat for heavy rain or stronger thunderstorms increases later this week.
