A Busy Weather Day Ahead…In August

Here in Portland July through mid October is the deadest time of the year weatherwise, with September generally being the peak of the boring weather season.  That’s because we rarely get thunderstorms west of the Cascades.  But today is one of those rare times in which we could see some real action.

The reason is that we have a rare combination of lots of moisture all through the atmosphere, including here at the surface.  Plus a very warm atmosphere overhead.  The upper-level flow is southeasterly over us, which is bringing in more moisture from the southeast.  The atmosphere is unstable, which means parcels of air want to suddenly rise through the atmosphere and form those huge thunderheads.  And the final trigger for today is the upper-level low that was off the California coastline is lifting north through the state of Oregon this afternoon.  Those factors have all combined to put anywhere in Oregon over and east of the Cascades in the SLIGHT RISK category for severe thunderstorms.  The primary danger will be damaging outflow winds and hail.

But even west of the Cascades we’ve seen the action early.  Take a look at the hundreds of lightning strikes right after sunrise in the north Oregon Coast Range and Willapa Hills!  lightning_tue Those were all strikes in a 30 minute period!  I see that one RAWS station in the Coast Range had almost an inch of rain in a very short period of time.  With such a warm and humid airmass it can rain like it does on the Gulf Coast…buckets at a time.

Here is the latest lightning  image for western Oregon as of 10:00am:

LightningNWOregon

A bit quieter, but I think we’ll really see the action pick up this afternoon and evening.  At least the cloud cover will keep temperatures much cooler than yesterday.  Although it’s a humid day, high temps will stay well below 90 degrees.

To recap…

  • ANYONE could see a thunderstorm today
  • Everyone will not see one though
  • Any storm could include very heavy rain briefly
  • Gusty winds are possible within a few miles of thunderstorms, that’s because air rushes out of the bottom of storms and spreads out below
  • East of the Cascades the risk for damaging wind and large damaging hail exists

Tomorrow we’ll see our coolest day in quite awhile, highs only around 70 and showers/clouds.  More of a gloomy May (or late September) day.

Chief Meteorologist Mark Nelsen

 

 

 

55 Responses to A Busy Weather Day Ahead…In August

  1. Karl Bonner says:

    Hey, has Mark or anyone else noticed how the Euro at days 7-10, as well as the GFS to a lesser extent, is giving us signs of a fall-like east wind event around the 22nd-24th of August? If it verifies, it could be the coolest and crispest such pattern in late August, since 1992….

    http://www.ecmwf.int/en/forecasts/charts/medium/mean-sea-level-pressure-wind-speed-850-hpa-and-geopotential-500-hpa?area=North+America&step=0&relative_archive_date=2014050912&parameter=Geopotential+500+hPa+and+Temperature+at+850+hPa

    • W7ENK says:

      An East wind into Portland generally translates to warmer temperatures in August and September. The switch to “cool(er) and crisp(er)” doesn’t usually happen until mid October. To have a cool(ing) East wind in mid-late August would be exceptionally rare.

  2. Tyler Mode says:

    Here is a video from Stevenson, Washington. Just captured one bolt as you’ll see here, with the thunder. Then the last part is a time lapse of the storm.

    I didn’t notice until I sped it up the very clear rotation on that storm.

    http://www.4shared.com/video/LbLqlXsiba/Gorge_Lightning_and_Rotation_8.html

    Also, here is a short time lapse of the storm near Woodland earlier in the day:

    http://www.4shared.com/download/Wqnzk7eOba/Woodland_TL_Final_81214.m4v?lgfp=1000

  3. High Desert Mat says:

    Felt like autumn today here in Redmond. Temp up to 73 then down to 63 all day long with showers and a rogue thunderstorm. So depressing lol, I want summer back for another month and a half.

  4. WEATHERDAN says:

    81 and partly sunny in South Salem at 3:15 PM. Looks like low 90,s for Sunday-Tuesday in Salem then cooling back to the 80,s later in the week with maybe some additional convection. CAPE looks promising next weekend ( 8,23 ). Got down to 59 here in Salem last night so yet another warm night. 84 For Friday and then 88 for Saturday so our cool spell lasted just 1 day but it sure felt nice to feel the rain on my face. I heard some climatologist on TWC say today that there has been a 71% increase in extreme precipitation events in the last 10 years. Well no surprise if the atmosphere is getting warmer. The atmosphere can hold more water the warmer it is. We certainly live in interesting times. Peace.

  5. Karl Bonner says:

    “July through mid-October is the deadest time of year, especially September.”

    Why does maximum boredom seem to come so close to fall, rather than midsummer? Does it have to do with the still-warm airmass but rapidly weakening sun, adding up to create more stability overhead?

  6. Rainy summer-snowy winter!( Mark,what you think?)

  7. GKELSO says:

    Did anyone in the Longview/Kelso manage to capture any good pictures and/or video of the storm that rolled through yesterday afternoon? I only got see a few of the many lightning strikes and since I was class most of the duration I only really got to hear the thunder, albeit loud as hell, the strikes were mostly out the window opposite the instructor.

  8. schmit44 says:

    8/13/2014 Oregon (All) Temperature Summary

    Warmest:
    High:90 at JUNIPR( 359 ft)
    Low: 68 at JUNIPR(359 ft) & WYETH(102 ft)

    Coldest:
    High:52 at Rim(7050 ft)
    Low: 37 at CRAZYMAN FLAT (6100 ft )

    Largest Diurnal Change: 36 degrees
    EW2055 Prairie C (83/47 ) (3547 ft )

    Heaviest Rainfall:
    1.12″ at BEND WATERSHED(5330ft)
    0.72″ at BOARD HOLLOW(4188ft)
    0.62″ at CW2551 Medford(1491ft)
    0.61″ at DW9680 Sunriver(4164ft)
    0.57″ at CW3932 Central P(1290ft)
    0.57″ at AA7OA Astoria(240ft)
    0.53″ at LAVA BUTTE(4650ft)

  9. High Desert Mat says:

    Made it to a solid 77 today. I think the next week or so will be warm but nothing unusual for this time of year. The nights are getting longer and therefore the heat of the day is getting more of a spike to it. It doesn’t happen as quick and doesn’t last as long. Wow, I sound like a man getting older huh? Jk. Anyways fall is quickly coming and before we know it were all gonna be begging for 70’s. Hope the vacay was fun Mark. Get em while you can!!

  10. Tyler Mode says:

    76 today. First below normal high since July 25th. Felt kinda nice actually!

  11. runrain says:

    Ha! The 2:20pm visible satellite has a clearing area down by Lane County in the shape of a question mark!!! A sign from above??

  12. Jake-(Gresham) says:

    The thunders got no boom boom. 😦 This cloudy overcast is starting to bore me – let the heatwaves come back I say!

  13. WEATHERDAN says:

    Partly cloudy this morning and 72 in Salem at 11:45 AM. No precip so far today. 58 this morning. Another warm morning. By Thursday afternoon the sun will return and so will the warmth. 86-91 for the next week or so with no Thunderstorms. So I guess it’s back to watering the lawns. Did some checking and in that ultra hot Summer of 1967 Salem had 35 morning lows in the 40,s between June 1st and August 31st. So far this year just 11. And the last one of those was 49 on June 22. No doubt about it our overnight temperatures are much warmer now than they used to be. Oh well cooler weather is coming in a few weeks. The AMS picnic is on Saturday at about 1000 feet out in Happy Valley. Looks like lots of Sun and just about 80. Perfect weather for a picnic. Peace.

  14. Marcin says:

    Thunderstorms always fascinated me. How do you monitor lightning?

  15. W7ENK says:

    What a ridiculous waste of amazing potential for incredible thunderstorms over PDX. Yet another failure by Mother Nature!

    One word: DOME!

    Radar:

    Lightning:

    I seriously do not understand why this keeps happening, but it’s extremely disappointing.

  16. Tyler Mode says:

    0.16″ yesterday and 0.02″ so far today. Was hoping that rain up north would fall here. But, I think they also need it, it looks like the fires on the east slopes are getting some decent rain too.

    • W7ENK says:

      Just a few raindrops yesterday later in the evening, but I somehow managed 0.06″ overnight. It was just enough to make my ride to downtown this morning damp and chilly.

  17. David B. says:

    No thunder here, and it took a long time getting here and started really slowly, but then it just poured rain most of the night. No gauge here but it must have been over an inch (that’s what nearby stations all seem to have gotten from 1 to 1.25 inches).

  18. Jason Hougak says:

    What a blessing to get the much needed rain in the mountains during the middle of wildfire season.

  19. Jason Hougak says:

    I worked on Lolo Pass road yesterday on a well and I got hammered by that thunderstorm cell. Poured down rain in buckets and a fair amount of lightning and thunder… it was awesome!!!

  20. schmit44 says:

    8/12/2014 Oregon (All) Temperature Summary

    Warmest:
    High:101 at ECHO( 683 ft)
    Low: 77 at DW0462 Umatilla(390 ft)

    Coldest:
    High:56 at Port Orford(0 ft)
    Low: 37 at DIMLKE (4726 ft )

    Largest Diurnal Change: 40 degrees
    PROVOLT SEED ORC (93/53 ) (1180 ft )

    Heaviest Rainfall:
    1.40″ at RED HILL(4400ft)
    1.30″ at BLAZED ALDER(3650ft)
    1.29″ at POWELL BUTTE(3199ft)
    1.20″ at GREENPOINT(3200ft)
    1.12″ at DW9630 La Pine(4256ft)
    1.10″ at MT HOOD TEST SIT(5400ft)
    1.06″ at MILLER(1031ft)
    1.04″ at PARKDALE(1480ft)
    1.01″ at DW1028 Ajax(2090ft)
    1.00″ at MUD RIDGE(3800ft)
    0.95″ at DEE FLAT(1260ft)
    0.91″ at MADRAS(2441ft)

  21. Tyler Mode says:

    Regardless of how it turned out, I personally have never seen a Severe Thunderstorm Watch issued that included Vancouver/Battle Ground etc.

    I drove up into the Gorge with a bud and we were right in the middle of a storm with several close strikes just as the storm was dying. We headed to Stevenson and saw a few strikes there, but nothing too impressive.

  22. Boydo3 N. Albany says:

    NWS still calling for rain and t-storms tonight in their short term forecasm. I’m thinking we are done around here. I know I am.

  23. paulbeugene says:

    Lots of altonimbostratus dissapointus all around Eugene. Probably same scheiß around PDX.

  24. W7ENK says:

    NWS just pulled the plug, it’s over…

    EVENT CANCELLED
    NATIONAL WEATHER SERVICE PORTLAND OR
    524 PM PDT TUE AUG 12 2014

    http://inws.wrh.noaa.gov/weather/alertinfo/18233059

    Pardon me while I go cry myself to sleep now.
    😥

  25. gidrons says:

    Cell over the gorge

    [url=http://postimg.org/image/noxaejfqh/][img]http://s12.postimg.org/noxaejfqh/gorgecamera1.jpg[/img][/url]

    • gidrons says:

      Let me try that again
      [url=http://postimage.org/][img]http://s12.postimg.org/hb87baaul/gorgecamera1.jpg[/img][/url]
      [url=http://postimage.org/app.php]screen capture windows[/url]

  26. gidrons says:

    Watching the radar loop, I can see the dome at work.

    • David B. says:

      I feel that way, too! There’s all these showers over the south Washington Cascades that look like they should be moving north, and they sort of are, but they’re continually dissipating as they do. I guess I’m still in paying-back-the-debt mode for that day last year when there were so many thunderstorms that I lost count.

      72 degrees at 4:30pm, cooler than it was at midnight!

    • Dave in SW PDX (235') says:

      Nearly 6 hours later and The Dome is still holding strong. Looks like the ULL is centered right over PDX per NWS radar.

  27. Mike (Orchards 255') says:

    Wonder how many times PDX has been under a Severe t-storm watch. We are now.

  28. Lauraholic says:

    I’ve been enjoying watching the radar today. Stay safe everybody!

  29. W7ENK says:

  30. Muxpux (Castle Rock 175') says:

    Thunder rumbling nearly all day today, was up around 5:30 and could hear all the thunder over the hills, worked out on the kalama river today and that cell passed by, didn’t get rained on but impressive lightning and thunder. Still rumbling up here in castle rock from te cell up north. Love this stuff!!

  31. Tyler Mode says:

    BULLETIN – IMMEDIATE BROADCAST REQUESTED
    SEVERE THUNDERSTORM WARNING
    NATIONAL WEATHER SERVICE PORTLAND OR
    1258 PM PDT TUE AUG 12 2014

    THE NATIONAL WEATHER SERVICE IN PORTLAND HAS ISSUED A

    • SEVERE THUNDERSTORM WARNING FOR…
      NORTHEASTERN CLACKAMAS COUNTY IN NORTHWEST OREGON…
      SOUTHEASTERN MULTNOMAH COUNTY IN NORTHWEST OREGON…
    • UNTIL 130 PM PDT

    • AT 1258 PM PDT…DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
      CAPABLE OF PRODUCING QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS
      OF 60 MPH. THIS STORM WAS LOCATED NEAR THREE LYNX…OR 15 MILES
      SOUTHWEST OF GOVERNMENT CAMP…AND MOVING NORTH AT 25 MPH.

    • LOCATIONS IMPACTED INCLUDE…
      SANDY…MOUNT HOOD VILLAGE…THREE LYNX…ZIGZAG…BRIGHTWOOD…
      WELCHES…RHODODENDRON…BULL RUN AND SHORTYS CORNER.

    IN OREGON THIS INCLUDES U.S. HIGHWAY 26 EAST OF PORTLAND BETWEEN MILE
    MARKERS 25 AND 46.

  32. Tyler Mode says:

    That storm that moved through Woodland and north was very impressive with it’s structure. Also it spit out a ton of lightning.

    Now seeing cells develop over the Columbia River and moving north into Vancouver.

  33. High Desert Mat says:

    No way, in and around PDX its around 80 degrees right now. In and around Salem its in low 70’s. Didn’t think that was possible for it to be warmer in Portland than Salem. Hmmmm…. lol

    • High Desert Mat says:

      Currently 82 at my place and looking forward to the storms this afternoon. One or two severe ones today or tomorrow and I’ll be content for the rest of summer.

    • WEATHERDAN says:

      Matt if you want my vote for troll of the year don’t sweat it’s yours!

    • High Desert Mat says:

      Nothing wrong with a little jabbing here or there Dan. Lighten up a little please, life is short. Geez

  34. Yes we have thunder & some CC in Longview! Been waiting

    • That one was a flash & rumble over the top of the house Awesome! Smudge the cat will not like it she growls at thunder! I’m outside on the porch enjoying it! We have two cells over Kelso & Longview at present! With a third moving over from Rainier OR

  35. gidrons says:

    Pappoose – Incoming! Over the Dixie Mtn Radar dish as I type.

  36. Dringus says:

    Nice show out in Hillsboro at Intel. Saw about 15 strikes off to the NW.

  37. W7ENK says:

    I want a thunderstorm!!!

    • W7ENK says:

      But… I’d like it to wait until after my ride home. Biking to the South Waterfront from work at 2, then (somehow) riding back to Milwaukie at 4. The storms can begin at 5 and last all night long.

  38. alohabb says:

    If you want actiom head to north plains. Golf ball size rain drops and crazy lightning! One bolt hit the speed sign on hwy 26 as i was passing by.

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