Early Spring Thunderstorms

While thunderstorms, especially damaging storms, are common this time of year in the US, they are generally confined to the southern states. As the spring moves into April and then May, thunderstorm season moves northwards. As such, we typically don’t see such storms in the Northwest until May. But this unusual weather pattern tomorrow in late March is classic for strong storms in our area. So there is a threat of damaging storms tomorrow. 

Here’s the Storm Prediction Center’s outlook for tomorrow.  The yellow area has the best chance of strong storms, but they are also possible in the dark green area. 

We talked about warming into the 70s in our previous blog and that now looks certain.  That, along with other ingredients including a strong cold front, will create the storms. They’ll start down near Portland in the late afternoon.  Here’s what one computer thinks the radar will look like at 4pm Wednesday.

Then they will march north and east. They probably won’t make it north off I-90 until after sunset.  Here’s a forecast for 10pm. 

The main threat will be strong winds, although hail is also possible.  Tornadoes?  Obviously those are rare in these parts.  So I’d never answer “Yes” to that question.  But there are some weather parameters that suggest it’s not impossible.  It’s worth pointing out that the deadliest tornado in Washington state history occurred in Vancouver on 5 April 1972.  

Also worth pointing out.  The warmest March day ever in Spokane history was 74F way back in 1881.  We will see if that record falls tomorrow.  (Note, temperatures in 1881 were measured in downtown Spokane, not on the West Plains as they are today).

After the cold front blasts through overnight, temperatures will return to the 50s for the remainder of the week and into next week with occasional rain or showers.