PORTLAND, Ore. (KOIN) – We are about to jump into a four-day period of rain and thundershowers (it may even be five days). Knowing how our spring months have turned out in the recent past, there is always a moment that starts to trend towards dry conditions.

Will we extend the rain through May? Will we keep a traditional June gloom in place too? It’s possible. However, let’s approach this rainy stretch as if it may be our wettest day this month. What will it do for the Willamette Valley and is it enough to help out other portions of the state?

Right now, we have a minor ridge hanging over the Pacific Northwest. This ridge is going to forfeit all the positioning to a trough of cool unstable air. That will come riding in on Thursday, connecting to a fairly impressive stream of moisture. The combination of the two should lead to some rainy moments Thursday and Friday.

There will be a trailing trough that will swing the main axis right over the top of us by the weekend. Temperatures will have a hard time warming to the 60s — that’s not something that we see in May often. The daytime average for Portland is actually getting closer and closer to 70 degrees (May 18).

The weather story for the next five days will look something like the graphic below. We had similar days like this in April.

Over a 30-year period, the spring months average over nine inches of rain. Last year, the driest spring on record, only published 2.52 inches of rain. We have already surpassed the 30-year average this spring. That was due to a massive April rain total, the wettest on record.

That doesn’t mean we are working with house money this May for Oregon.

Yes, northwest Oregon is fairing well. The rest of the state, however, is still hunting for more water. It won’t do us any harm to bring in more rain here locally, too. Of course, we’d prefer that to be in moderation without dangerous flooding or landslides.

We are just four days into May and we have a splash of rain in the gauge, per the Portland International Airport. There have been plenty of showers and much higher totals around Portland this month. We had a stretch of heavy storms that dumped rain on the southern I-205 corridor just the other day. Some have already picked up over an inch of rain. With that, we are primed for more.

Where will that May total wrap up by this time next week? There is a good chance it is somewhere closer to the May average for the month.

A steady stream of moisture will arrive Thursday morning. This will impact just about everyone for the morning.

A southwest wind will keep us wet from the coast to central Oregon. This usually prevents a significant rain shadow for the valley. Notice the surge of moisture that is expected to reach locations like Madras and areas of Wasco county. This first system should help out some of the more deprived areas of Oregon too.

The steady rain may turn more to showers, but they will have the potential to be heavy at times. There are signs of more scattered showers on Friday than Thursday. You can cycle through the graphic slideshow below to get a visual of the incoming system.

In the short-term, Thursday may drop up to a half-inch of rain across the Willamette Valley. There may be some isolated locations that end up pulling in over half an inch of rain.

What is encouraging are those rain totals over on the other side of the mountain. Thursday is only day No. 1 of the extended stretch of wet weather that we will endure here in the coming days.

With so many microclimates and nooks and crannies here in Oregon, those rain totals can vary significantly. What is most important, is that the water is expected to spread across most, if not all of the state.

We have more in line, which shouldn’t be overlooked. Each day has the possibility to impact the commute both in the morning and afternoon.

However, it will be Saturday and Sunday that hold the threat of thunderstorms. That means isolated downpours and fits of small hail. If this holds true, it will probably end up being the most active slice of May. It likely will be enough for the northern Willamette Valley and the coast, the same locations that are already a step outside of drought conditions.

For the rest of the state, this stretch of rain will not be enough. It would be way more beneficial to keep the rain coming, while also factoring in a gloomy and wet June.