Much Needed Rain On The Way Next 4 Days

6pm Monday…

June has been very dry across the region.  Only .23″ in Portland so far this month, with just 6 days to go.

Month Climate Rain Calendar Saturday Start

This is our 5th consecutive drier-than-average June and most of the Pacific Northwest has been dry.

precipanomaly

But I see some hefty showers Wednesday-Friday, especially west of and over the Cascades.  What’s up?

A cool upper-level low is dropping down the Canadian coastline right now, and it arrives offshore by Wednesday morning.

wrf_500_wed

A couple points.  First, this isn’t quite as cold as the low that brought Timberline snow this past weekend.  The other is that as it approaches the upper-level flow turns southerly plus the airmass moistens up.  That begins tomorrow afternoon.  There are hints that some showers and/or thundershowers pop up across the region.  I think that’s most likely over the Cascades but can’t rule out a brief shower over the western valleys for your Tuesday afternoon.  Just keep an eye on the radar and sky tomorrow afternoon.

Far more likely is a three day period with widespread showers and embedded thunderstorms Wednesday through Friday.  By Thursday morning that upper-low is directly overhead = pretty good lifting.

wrf_500_thu_pm

This pattern in June is typically a very good rain producer.   By the time it leaves the area Saturday, the “new and improved” GFS (American) model gives us a nice soaking.  Maybe 1/2″ or more in the valleys and over an inch in the mountains.  Even a little in Eastern Oregon with thunderstorms.

gfs_totalprecip

The ECMWF is somewhat drier, sending less than 0.25″ into most western valleys of Oregon.

ecmwf_totalprecip

Both models shut off just about all the showers after Friday once the low moves to the north.  You can see it on the 24hr rainfall forecast from ECMWF ensembles.  Just about all the “rain action” is going to be Wednesday through early Saturday.

ecmwf-KPDX-indiv_qpf_24-1377600

To summarize

  1. Expect a cool, wet, & breezy period Wednesday through Friday
  2. Water sports won’t be pleasant Wednesday-Saturday…chilly!
  3. Thunderstorms are possible any of those days; could be a situation where you get 1/2″ of rain at your home and 5 miles away it’s sunny at the same time.  Think spring weather.
  4. At best we’ll see up to 1″ of rain in a few lowland locations by the time July rolls around a week from now.  At worst, just a quarter inch of rain to wet only the top of the soil.
  5. Regardless, this puts the beginning of fire season off for another week or two.  No major fire worries until the 1st or 2nd week of July.

Chief Meteorologist Mark Nelsen

30 Responses to Much Needed Rain On The Way Next 4 Days

  1. Sam says:

    Mark, what do you see Monday for Salem, Rain 35% at 8AM ?

  2. Tyler Mode in Battle Ground says:

    0.73″ on the day! 3rd wettest June day on record.

    My monthly total through yesterday was 0.68″.

    Here’s a link to a video of a close strike, best viewed HD.

    [video src="https://photos.smugmug.com/photos/i-McV6bFL/0/426c6260/1920/i-McV6bFL-1920.mp4" /]

  3. Gene says:

    My thunderstorm story originated . . . inside a movie theater! We were inside the Division Street Cinemas in the middle of watching a movie at about 7 p.m. when a loud alert came on (with matching strobe lights), telling everyone to exit the theater immediately. We go outside and it’s absolutely pouring, with thunder and lightning all around us. There was a big pool of water in the hallway near a couple of the theater entrances inside the building, which I’m assuming was a leak caused by the heavy downpour. Certainly not something I’ve ever experienced before in all my years of movie-going!

  4. runrain says:

    Lots of commercial aircraft circling south of PDX. Some diverting to Seattle.

  5. PAUL D says:

    Was beginning to wonder if today’s forecast was going to be a bust because it was sunny most the day, but the clouds rolled in and DUMPED on Hillsboro real good!! WOOT!!

  6. Steven Shapiro says:

    That was fun! Sw pdx…

  7. EY (Oak Grove) says:

    Flood Advisory through the east side of PDX Metro… Amazing… Also, it sounded like a bomb went off right outside of my house… Not used to having lightning this close.

  8. Larry says:

    Had a few brief thunderstorms just after 6:00. My lights flickered a few times, lots of lightning and thunder. Winds up to 35 mph caused some debris to fall onto the roadway. Surprisingly had no hail from the storms. Looks like all the action is now done Woodburn to everywhere south of that. Overall, quite an event for us, and I’m excited for the continuation of thunderstorms tomorrow!

  9. runrain says:

    Amazingly intense thunderstorm here in Happy Valley. Never seen anything like it!

    • EY (Oak Grove) says:

      Think it’s related to the one that popped over me an hour plus ago… Light shower, then really fat and heavy rain then nothing. Looked like moved east

    • pappoose in scappoose says:

      Had some rumbles yesterday, started at 5:30pm.
      And again today! Have had rumbles since about 6pm, louder/more frequent today. Happiness.

      • EY (Oak Grove) says:

        Think a transformer blew just nearby… Over 17k without power… And ANOTHER big rumble as I’m typing this.

  10. EY (Oak Grove) says:

    Got my first rumble of thunder after a brief but very intense shower, couldn’t tell if it had hail.

  11. WEATHERDAN says:

    75 and mostly sunny. What cool showers? Seems just like those Winter can’t miss snow storms that frequently do. Peace.

  12. Joshua Lake Oswego says:

    Latest model runs are moving the bulk of the action north of us. A lot of us will miss out me thinks.

    • Roland Derksen says:

      I can see some heavy -looking clouds on the SE horizon, but just how quickly they’ll get here in BC or how much rain it’ll amount to, is uncertain. I’ll send in a report tomorrow.

  13. david wilson says:

    Happy, NO EAST WIND.Still in Hendersonville Nc. Now here when they say rain, it rains like wise with thunder and lighting. very nice storms at 80. Sunny today 90. Off to Myrtle Beach in seven days.10 days each in two different campgrounds. The good life. Hey Mark my wife noted last nite will be first time we will miss you on the 4th, in well, alot of years.

  14. paulbeugene says:

    Looks like good chance for some relatively strong thunderstorms starting around 4-5pm in Eugene, working way up the Willamette Valley to PDX by 8pm. Am liking the insolation we are getting this morning.

    • Ken in Wood Village says:

      I totally agree. Looks like things are coming together to make some strong thunderstorms. Looks like NE Oregon could have severe thunderstorms too.

      Tomorrow could be very interesting too.

    • runrain says:

      10:41am discussion certainly hints at the chance of some stronger storms. It’s also a bit warmer today than expected. Temp at 73 at 2pm when only upper 60’s originally expected.

    • runrain says:

      Severe Thunderstorm Watch now in effect for the Roseburg area.

  15. PAUL D says:

    Why does it always rain in the morning when the forecast is for the rain to start in the evening?

  16. Roland Derksen says:

    Thanks to a few showers yesterday and the day before, we’re up to 0.36 inches here- that’s still at record low level!! But the forecast is saying we’ll get a lot closer to an inch (maybe more?) by Friday.

  17. PAUL D says:

    I can guarantee you that Thursday will be WET because my daughter & I are renting a Corvette for the day 😦

    We’re taking one for the team – you’re welcome!!

  18. Pat says:

    We need a good soaking. Hopefully some thunderstorm action, too.

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