Hot weather continues with widespread moderate to high heat risk expected today. Fire Weather Watch in Effect Late Thursday for Interior Northern California.
Discussion
The models have not been doing well lately with a big shift in a day or so from a ridge over the area on Thursday to a trough. Good and bad news with this change. Good news is the heat will be moderated by the incoming through and clouds so have ended it tonight at 9 pm.
The bad news is we are now expecting scattered thunderstorms to move over the interior mainly Thursday night into early Friday morning. The low will first bring chances to the coastal range late in the day. Chances extend into the valley Thursday evening mainly central Sacramento valley northward then after midnight over Sacramento and into the northern motherlode and mountains mainly Plumas county northward.
By late at night the activity should shift over the Northern San Joaquin valley eastern Sacramento county and the entire motherlode/mountains. The low does progress east during the day with Thunderstorm chances ending during the morning. Thunderstorms look like they will be a mix of dry and wet but generally less than a tenth of an inch of rainfall for the lower elevations. Higher up along the western slopes maybe around a quarter inch or so with the stronger ones.
Winds will also increase over the ridgetops on Thursday with gusts generally 25 to 35 mph ahead of the wave that moves in later Thursday. This will also increase fire weather concerns ahead of the thunderstorms that are expected and its associated problems. Cooler temperatures Friday behind the trough with activity gradually ending over the southeastern portion of the CWA during the morning.
A flat ridge on Saturday over the region will warm temperatures 3 to 5 degrees over Fridays high temperatures.
Extended Discussion (Sunday through Wednesday)
Temperatures will warm to a little above seasonal normals for this time of year on Sunday with a flat ridge still in place over the region. Still some uncertainty in the clusters early next week. Broad troughing over interior NorCal looks to be the most favored solution at this time, which would keep temperatures closer to seasonal normals and could bring locally breezy winds at times to the Delta and ridgetops. Dry weather is expected in the extended period.