Tri-Cities weather
May 9, 2023
An upper level low pressure system is moving eastward into the Northern Rockies Tuesday morning. Rain showers and isolated thunderstorms, mostly south of the Tri-Cities, will taper off into midday as the low moves deeper into Idaho. Maybe some clearing midday before clouds from mountain thunderstorms develop this afternoon. An isolated thunderstorm may make it into the Columbia Basin but widespread storms like what was observed Monday aren’t likely.
Highs this afternoon around 70°F. Thunderstorms fade after sunset allowing for some clearing and a low near 50°F. Another low tracks overhead Wednesday for increasing clouds in the afternoon, mountain storms, and another chance of an isolated storm making it into the Basin.
Looking dry Thursday and beyond as ridging builds over the West Coast to produce the first strong heat wave of the season. Models are currently favoring several days with highs in the mid to upper 90s beginning as early as Saturday. Highs above 100°F lie within the realm of possibilities early next week.
The earliest 100°F high on record in the Tri-Cities occurred on May 13, 1993. I don’t expect to beat this with this heat wave as as the warmest days currently appear to start May 15, but it is still far enough out that this could change. The average first 100°F day is June 27. It is possible that we beat a few daily record highs during this event. Average highs are around 77°F.
