NWS: Increases in Heat and Thunderstorms Expected

NWS Medford forecasters report the main threat in the forecast continues to be lightning from thunderstorms. This will become more notable over the next several days as we see an increase in activity through the week, especially the eastern two thirds of the forecast area where the highest chances for thunderstorms exists. There could be a threat for isolated flash flooding in areas that are more susceptible and where slow storm movement is coupled with repeated development.

We will also have a chance for severe weather, and this could come from hail and wind gusts mid-week (Tues-Thurs). Lastly, above normal highs (+10-15 degrees) are expected inland today and tomorrow, so we could have heat related issues for those who are more susceptible.

For today, thunderstorm activity will increase later this afternoon with lightning being the main threat as a low moves over Southern California. That should lead to storms generally moving from east to west today, increasing westward in coverage through the afternoon and evening hours. Severe weather appears unlikely given the weak parameters. Showers and isolated thunderstorms could make it as far west as the I-5 corridor. Again, lightning is the main concern today.

Besides a dissipating high cloud shield leftover from Sunday’s storms, the area will remain clear this morning. Cumulus buildups and isolated storms are expected again in the afternoon and evening along the Cascades and in northern California, with the highest probability over the mountains. However, there is a 25% to 30% chance of a thunderstorm in the Klamath Basin and a 10% to 15% chance at the Medford Airport tomorrow. Model reflectivity from the high-resolution model indicate that storms will start popping up near Klamath Falls as early as 2:00p or so.

There’s also good agreement some isolated storms will make it into the Rogue Valley, so while there isn’t high confidence in thunderstorms impacting the Medford Airport directly, forecasters will continue to monitor for any potential changes.