Could Be A Fun Weather Night!


Our best chance for a nighttime lightning show so far this summer is tonight.  Everything seems to be lining up for lots of flashing, rumbling, and downpours SOMEWHERE between Eugene and Seattle; and the Portland Metro Area is right in the middle.

A cool upper-level low pressure center has been sitting off the southern Oregon coastline for two days spinning moisture and occasional showers/thunder to it’s north.  This afternoon we’ve already seen surface-based (from the heating of the day) storms fire over the Cascades.  One briefly turned severe with large hail detected just west of Timothy Lake but it’s weakened now.

The setup is very good for a widespread thunderstorm outbreak from northwest Oregon through southwest Washington.  The upper low makes it’s move to the north right over us late tonight and early Friday morning.   The combination of ample moisture, lifted index down around -4 (5pm-2am), CAPE values up above 500, and good divergence aloft (for lifting) all screams “ACTION” to me.  Plus a nice SSE upper level flow.

So when?  That’s a tough call.  Our RPM model shows storms coming down off the Cascades around 8-10pm, then another surge with the actual upper level low right around sunrise.  The WRF-GFS has more generalized storms firing at times overnight.  Both models show better conditions with the low slightly farther west than what was forecast 24 hours ago.

So now we just sit back and keep a close eye on the radar and satellite imagery…more updates later most likely.

Chief Meteorologist Mark Nelsen


105 Responses to Could Be A Fun Weather Night!

  1. runrain says:

    The Dome is gettin’ blistered!!

  2. WhiteEagle - Garden Home / SW Portland says:

    Distant thunder…getting closer; right on time, Mark!

  3. chiefWright (Marquam, 380') says:

    Anybody on in Canby? Looks like the action just passed overhead?

  4. Sandi (Wilsonville) says:

    Lots of action right overhead! Switched to mobile now.

  5. flurball says:

    Just saw a cloud to ground strike I would say in the Stafford Rd area from my view in Clackamas

  6. AlohaWeather says:

    Faint thunder beginning to be heard on the west side while in a quiet location. 😀

  7. runrain says:

    Ok, W7enk. That CG must have been close to you! HV concert stopped, prob due to this storm.

  8. 8:18 PM and not a bad start I’d say ? ….

  9. chiefWright (Marquam, 380') says:

    Road looks pretty wet at Santiam junction on tripcheck cam, Detroit lake just looks dark.

  10. Sandi (Wilsonville) says:

    Starting to sprinkle and we’ve heard 2 rumbles of thunder… so far.

  11. Hal in Aims says:

    just looking at radar……looks like most of this stuff (for now anyway) will slide west of us…

  12. chiefWright (Marquam, 380') says:

    OK, now quieting. Precip was never more than a sprinkle, and radar showing we’re now in a quiet zone. Tstorm now likely over Molalla. Can see the mass heading to Estacada; can’t see lightning, but it’s a good 15 miles east.

    • chiefWright (Marquam, 380') says:

      OK, cell bearing down on Estacada may be widening, saw a strike from that mass maybe 8 miles away…

  13. AdamInAumsville says:

    So far the storms are very pulse like in nature.

    • runrain says:

      MY pulse right now is very pulse like in nature ! Hearing that thunder in HV too now. Dogs are a-barkin’

  14. W7ENK says:

    Thunder to the South of me, the dog is going nuts…

    • chiefWright (Marquam, 380') says:

      Dog is cowering under the desk…

    • Mr Data says:

      Pffft here but it’s just as well since me and Mom both having eye pain trouble and having to take drops which I was trying hard to avoid. :p

      When will the marine layer kick in to cool it off?

    • W7ENK says:

      Lots of lightning and almost constant thunder to the South of Milwaukie!! Getting louder…

    • Mr Data says:

      And when it’s humid I get cranky. 😦 Last update unless something happens.

      I admit I am bipolar and tend to go from one extreme to the other more often when I do not keep myself in check and push it too hard.

  15. Huge storm west of Eugene…. This is getting fun!

  16. Brad says:

    Perhaps the most important link of the night….

    Will we fill the western valleys with yellow?

  17. Just wait until the upper levels cool off after dark and the stronger lift arrives. Ohhhhh yeahhhh!

  18. New storm south of Estacada….

  19. New storm southeast of Eugene south of Lowell looks pretty strong. VIL showing already….

  20. Storm near Molalla now has tops over 35000′! Look for perhaps rapid development.

    • chiefWright (Marquam, 380') says:

      Concur. Have had at least 5 CG strikes in last 5 minutes about 2-3 miles to the east.

  21. chiefWright (Marquam, 380') says:

    Just started sprinkling, and now a couple of strikes just to the east. Judging from radar, looks like we’re at the northern edge of that mass that’s working its way thru Marion co

    • chiefWright (Marquam, 380') says:

      Yipes! It’s starting to look ugly out there. A really strong couple of strikes maybe 2 miles east; incoming!!

    • chiefWright (Marquam, 380') says:

      Cloud mass & precip looks mostly to the east, moving slowly NNW. Lines up with a little cell that’s pointing straight at Molalla!

  22. AdamInAumsville says:

    It is 81 degrees here and raining. Never seen that in my life in Oregon. No lightning or thunder yet.

  23. AM Radio suddenly becoming much more active. Is anyone in Albany or Eugene hearing Thunder?

  24. runrain says:

    Pretty loud roar over by PDX. Prob just the F-15’s out for a night cruise.

    Should be an awesome sunset coming up too, by the way.

  25. WV Loop Update
    24 hours Loop
    Upper Lever Low is now beginning to kick out. Appears to be 85 miles west of Cape Blanco moving north. Great trajectory.

  26. *BoringOregon* says:

    Well I hope some thing happens ?!?

  27. Brad says:

    Whoa. Those stroms SE of Salem sure look to be getting their act together.

  28. alohabb says:

    Rob…you are at your finest tonight! I dont understand half the ‘ish you say…but your exctiment comes out at times like this.

    BTW…the new Frosty Cone stinks..the frosty melts too fast and its like a milkshake cone. Random

  29. Wow. Huge rapidly exploding t-storms just south of Roseburg.
    Zoomed Radar

    Very large VIL core, so a Severe Warning is likely. OH and, this is NOT surface based as Mesoscale Analysis shows little to no SB/MLCAPE and a CAP in place! This is elevated apparently. This appears to be due to the better lift now moving north. If this is ANY indication for later? Look out. I’m not saying it is, but this is something to keep an eye on.

  30. Okay checking the 23z HRRR run. What’s the “HRRR” you ask? I have no idea. No, really, it stands for High Resolution Rapid Refresh, and within 12 hours it is a very good convective model. Storm chasers swear by it. The run is not complete, but it is out to 9 hours and here are the highlights…..

    Okay, so this shows a complex of storms moves up the Willamette Valley in 5-6 hours(11 PM – 1 AM) and another area of storms over Clackamas County 1-3 AM. MUCAPE 400-1000J/kg(Highest north of Salem) A core of focused Shear with 0-1KM 50-55kts! 0-6KM 45-55kts. VIL indicating potential for pea to dime sized hail. My thinking is this looks excellent for several rounds perhaps of elevated storms and given the shear forecast(IF it is realized) I would not rule out some strong, perhaps briefly severe warned storms. We’ve seen it before, albeit that it is rare.

    Latest 21z SREF is running now and as it moves along I’ll post details later.

  31. Wendy-Silverlake says:

    Will there be any organized moisture tonight/tomorrow, or just the thunderstorm possiblities. Trying to get ready for a BBQ and need to mow the yard tomorrow. Thx

  32. Brad says:

    Bolt of lightning and thunder here in Battle Ground.

  33. chief says:

    totally off subject, somewhat. steph is is looking sexier than ever . long time viewer. my wife had that same fresh healthy look when pregnant ! cheers to women!

  34. pbo9 says:

    I want thunderstorms. I want thunderstorms! I want THUNDERSTORMS!

  35. W7ENK says:

    I’m not feeling this for areas East of Molalla/Sandy/Troutdale. Gresham might get in on the action, but I think for the most part the bulk of PDX Metro gets missed. Best we can hope for is lightning off to the East visible after dark, and maybe distant thunder heard from areas East of I-205.

    I seriously hope I’m wrong…

    • If the ULL tracks as expected we should, or could see widespread elevated storms on both side of I-5/205. In fact, I’m expecting it after 10 PM.

    • Mark Nelsen says:

      I’ve already decided…you’re going to be wrong Erik.

    • Brad says:

      Yeah, no big storms, but everyone should see lightning and get a few fat drops.

    • Brad says:

      @mark…that’s awesome. Weather Eeyore be gone!

    • W7ENK says:

      SWEET! Thanks Mark! 😆

      Rob, I’ve got an eye to the sky and my camera charged and ready. I want a light show that will put the fear of God back in me!!

      Let’s do this!!!

    • If we get weather that destroys my garden…I am going to be really upset. The best garden I have ever had and I have worked so hard. 😦 I do like a good light show though!

    • W7ENK says:

      Realistically, looking back, aside from the one rogue cell that shot out across the far S side of the Metro area, my assessment was pretty spot-on accurate… until you get to the magical Columbia River. Something strange always happens with thunderstorms at the river.

  36. Mark, thanks for the update. I agree with everything you’ve said here, and I am encouraged when I look at 500mb, 250-400mb charts. Very good dynamic lift and large scale ascent is slowly moving north. Shear is slowly increasing also how showing 40-50kts 0-6/0-8km.

  37. Hal in Aims says:


  38. Hal in Aims says:

    light shower……..dark….no thunder……..perhaps quiet until later…

  39. pappoose in scappoose says:

    The scouts are gathering.

  40. Raining in Boring…dark sky but no thunder.

  41. weathercrazy82 says:

    I’ll be headed out later tonight, or tomorrow morning, just not sure where yet!

  42. Hal in Aims says:

    if it holds together….the cell in east-central clackamas county is pointed right at me…

  43. runrain says:

    Like! (First?)

  44. Timmy_Supercell (Hillsboro, OR) says:

    FIRST!!! It IS going to be a fun night!!

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