If we don’t set a new temperature record on Wednesday, we should get close enough for it to really not make a difference. Sunny skies with variable levels of haziness will result in a high around the record of 104 degrees. As we move into Thursday, a lighter southerly flow will allow some afternoon cloudiness to build up, with only an isolated thunderstorm, mainly to our south and east. By Friday, a stronger push of southerly moisture will bring increased thunderstorm activity, as temperatures fall slightly to the upper 90s, and those basic conditions will last through the weekend.

Reno Tstorm

So why are thunderstorms more common in the afternoon? This time of year, this kind of weather pattern occurs because ground temperatures get warmer faster than the temperatures up at about 20,000 feet. This creates instability, and pockets of air will rise during the heat of the day, and that vertical motion creates the thunderstorm cells. And the longer the pattern stays the same, the more likely thunderstorms will form the next day. Why would this be? I’ll tell you tomorrow.

Thermal Thunderstorms