9:00pm Sunday
Surprise…it’s still raining! What a gloomy April Sunday don’t you think? We’ve picked up about a third of an inch of rain here in Portland, but more than 1/2″ fell once again in Salem. Yesterday over 2″ fell in parts of western Washington. Yes, April has been much wetter than average. We’re halfway through the month; check out those monthly totals so far!
That Portland total is the 4th wettest first half of April on record. We’ve seen rain on 12 of 15 days this month:
But the weather pattern will become far more “reasonable” this week. By that I mean we’ll be drying out quite a bit…after Tuesday.
Tonight we have a deepening surface low pressure center traveling straight north through NW Oregon and a 2nd low moving north through Eastern Washington and northern Idaho. Here’s the 8pm position of the low:
By 2am note the lowering pressures over Washington, both western and eastern sides of the state. Quite a southerly gradient through the Willamette Valley!
Then by 8am the weaker low has been absorbed by the 989mb center in southern British Columbia. This is a windy pattern for the Pacific Northwest so you can expect a windy day Monday after tonight’s gusty wind.
We’ve already seen gusts in the 30-40 mph range in parts of the Willamette Valley and south metro this past hour. I see a 35 mph gust suddenly just arrived at I-205/Division ODOT sensor and a 39 mph gust at Aurora. We have 12-18 hours of wet & windy weather on tap.
Here’s the good news! In the past 3 days models seem to be keying in on a change…actually 2 changes for the next 10+ days:
- The upper-level troughs moving along the westerly flow appear to get weaker/milder and don’t dig as far south
- Upper-level heights rise as the weakening spring jet stream pushes farther north more often.
The result is a significantly drier and somewhat warmer weather pattern. It appears we’re going from mid-March cold troughs to more of a May-type pattern. Take a look at the ECMWF ensemble precipitation forecast:
You can see almost all ensemble members are dry from Wednesday through early next week, minus the shower chance Saturday morning as a trough passes by to the north. This is the driest chart we’ve seen in many weeks, maybe since early February. Notice temperatures rise quite a bit too, this is from the 18z GFS:
To wrap it up…AFTER Tuesday I see a much milder/nice mid-spring weather pattern ahead. Not totally dry, but our gardens/lawns/fields will get a chance to dry out.
Chief Meteorologist Mark Nelsen