An Early Summer Soaking; Wettest Weather Since February

June 13, 2021

8pm Sunday…

Quite a soaker eh? A warm and humid southerly flow has given the metro area somewhere around an inch of rain since it started yesterday evening. PDX has officially picked up .86″ as of 7pm with more approaching. I’m guessing that by the end of today (as early as 9pm?) WE WILL SEE MORE RAIN OUT OF THIS THAN ALL OF APRIL + MAY COMBINED! In a typical spring we’d get something like this maybe every few weeks. Not this drought year. The numbers so far…

By the way, in Portland we’ve haven’t seen this much precipitation in two days since…wait for it…the big snowstorm day! That’s Friday, February 12th (and into Saturday the 13th). Of course it was all frozen precipitation (mainly snow) that day for much of the metro area.

A few areas have picked up over 1.50″…notice all (so far) over/west of I-5. Models have done very well sending the heaviest rain over there. This map isn’t real pretty, but it shows any location that has picked up about 1.50″ or more as of 7pm. That’s a huge soaking around Salem and Corvallis.

Of course in a warm and humid airmass with southerly flow one can expect thunderstorms in the Pacific Northwest. We’ve seen quite a few fire up over north-central Oregon, even as far west as the eastern edges of the metro area. In fact at 7:30pm this soaker was right over the Hood River Valley. Luckily it’s moving fast so the heavy rain won’t last long. You don’t want a 3.50″ hourly rain rate to sit still…

Ahead of today’s system, it’s been HOT in Eastern Oregon. Check out the afternoon numbers…close to 100 in a few spots!

What’s ahead?

More humid and warm weather tonight as the main upper-level low continues to spin offshore.

But good lifting that would produce significant rain tonight and tomorrow seems to go away. So showers continue tonight, but then we get a break again tomorrow. Other than leftover morning showers (mainly east metro), it should be a MUCH brighter day and mainly dry. Sure, maybe a shower here and there, but widely scattered stuff. Lots of fresh rain-cleaned air too.

As the cool upper-level finally “kicks out” to the northeast and over us Tuesday, we get a round of showers. Maybe a thundershower midday too…maybe.

By midweek the hot upper-level ridge to our east has been pushed south & east. But then a new ridge is developing in this spring’s favored position; in the Gulf of Alaska. That leads to weak and warm westerly flow to our north. This is a warmer than normal pattern for mid-June, but not hot. 850mb temps on our models are generally well under 20 degrees with no sign of significant offshore flow. So our forecast highs remain in the 80s for now. Weather systems will stay away Wednesday through at least next weekend.

Looking farther ahead (this map shows anomaly), the pattern remains the same through early NEXT week. This is NEXT Tuesday. We don’t have a hot ridge of high pressure overhead, but it’s close enough to cut off any rain chance. That’s what we’ve seen much of this past spring.

The ECMWF ensemble forecast for 24 hour rain is the driest I’ve seen in weeks. Very few members produce even light showers over the next two weeks (after Tuesday). So…this was a one-shot deal rain-wise.

Enjoy the rest of the rain this evening, and you can look forward to some warm sunshine later this week as a July-like weather pattern arrives.

Chief Meteorologist Mark Nelsen