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NorthBurnabyWeather

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  1. I guess my question is too simple to warrant a response... :/
  2. The last few days have been pretty humid, but I noticed much cooler breezes this afternoon. What's been going on at the BC/WA surface/mid-levels over the past 12-24 hours that can explain this?
  3. Have the Puget Sound Lowlands ever gotten a thunderstorm-related WW? I'm not talking about SW WA (Olympia, Cowlitz County) where such WWs aren't actually very uncommon, but the more populated areas along the Duwamish River/Elliott Bay drainage areas and the Cascade foothills.
  4. When was the last time a heat wave ended with widespread thunderstorm activity in coastal sections of WA/OR/BC, instead of the more typical marine push and shifting winds? Continuing on that subject, has there ever been a cycle of heat, storms, more heat (i.e. the storms don't bring much relief) in these parts? Such a pattern is fairly typical in the Mid-Atlantic Finally, will this forthcoming monster heat wave bring elevated humidity levels and lows in the 70s? Like, 3pm dewpoints in the upper 50s-low 60s (15-17 Celsius), pretty much Arizona monsoon-level.
  5. The pre-storm orange sunset in Vancouver on 7/25/09. I'm still not sure how that was caused
  6. Willamette Valley wipes the floor with the Puget Sound lowlands and Bellingham/Metro Vancouver for thunderstorm development and it's no contest. No geographic barrier against moisture flows (like the Olympic Peninsula/Range and Vancouver Island) since there are gaps in the Oregon Coastal Range near Portland/Vancouver; plus the more southerly latitude and the topography of valleys supercharges daytime heating. 4/5/1972 North Portland/Clark County F31/10/2008 Clark County EF1 and accompanying supercell6/4/2009 severe warned storms in PortlandAlso note that on 8/12/14, the SPC WAWAs were all south of Lewis CountyI don't think Seattle, Mount Vernon or Bellingham have ever had SPC WAWAs, not even from the storms 4 weeks ago (most of the action was around Olympia/Lacey) or 5/31/97.
  7. Hottest: July 21, 2002 in Chicago (where I was on vacation). The AT/DP split in the south west suburbs (where my aunt's house was, I was staying with her family) was 97/70, 106-107 heat index. WIthout exaggeration, I thought I was going to die. Besides a brief soujourn to the Maryland suburbs of DC the previous summer (and even then it was more of the typical 88/69DP Mid-Atlantic kind of summer), I had never up to that point been exposed to conditions even a quarter as hot or humid. And I was only 11 at the time, so I was very young. My aunt and uncle had me stay indoors that day as much as possible. Coldest: Probably the cold snap of February 2014 in Metro Vancouver. -10ish in Burnaby?
  8. I think Portland's summers are a lot more arid than London/Paris because the monsoonal influence in the PNW is nothing compared to the hot/humid spells that can be triggered by Spanish Plumes coming off the Iberian Peninsula, which also trigger violent thunderstorms.
  9. There are plenty of threads discussing memorable weather events during the colder months, like windstorms, heavy snow events, etc. However, I don't think there's a thread discussing the extreme weather events that can happen in the warmer months, like thunderstorms and heat waves. Obviously they're a lot rarer west of the Cascades than they are in the Paulouse, central WA/OR, the Idaho Panhandle, etc. (where thunderstorms and wildfires are pretty common in the summer, and even haboobs can occur), but that doesn't mean they can't happen in areas closer to the coast. Especially in the Willamette Valley which gets pretty hot; days in the upper 80s and lower 90s are a lot more common than in the Puget Sound lowlands or in Whatcom County/Metro Vancouver, and the warmer temperatures (plus the fact that Portland is situated further south) can fuel more potent thunderstorms than one might expect for the PNW. As an example of this, I don't think the Puget Sound lowlands have ever had a severe thunderstorm watch/warning, ever. However, the Willamette Valley/SW WA have had a handful of severe-warned events. Clark County seems to get the brunt of it. There was the F3 tornado on 4/5/1972 that tore through northeast Portland before killing six people in Vancouver; the 1/10/2008 supercell that also hit Vancouver (ironically, both of these events were during the colder months); the 6/4/2009 severe thunderstorm event in the North Valley; there was even a severe thunderstorm warning around the Columbia Bar area (e.g. Astoria) during the Ides of October windstorm last year. Not to mention the 8/12/14 severe thunderstorm watch for Cowlitz County. Anyway, I'm getting ahead of myself. What are your memories of extreme warm weather events that occured west of the Cascades? The 106 degree day in Portland, the 8/3/1999 thunderstorms, the 8/29/2015 summer windstorm, the 6/28-7/3/2013 heat wave (with elevated humidity levels); for you older folk, the 8/23/1993 thunderstorms where that jogger on the Eastside was fatally struck by lightning, etc.
  10. I know it's February, but I've always wondered: what do you think have been the most catastrophic fire weather scenarios in the PNW throughout history. Like, a complete burn ban for all of WA/OR/ID/MT, on top of a complete campfire ban for all of British Columbia. Summers of 2003, 2014 and 2015 spring to mind.
  11. Hi all, I hope you had a good holiday. Over the holidays, I've been trying to get a handle on upper air and surface analyses, and see if I can deduce the setup to thunderstorm events. Why did BC's Lower Mainland and Fraser Valley get rocked on August 7, 2012 and May 2, 2016 while Seattle and Portland were untouched? Why did Seattle get storms on August 2, 2014 but Vancouver did not? That kind of thing. Growing up in the Northwest all my life, studying upper air charts via Plymouth State University have allowed me to recognize several "over-arching" setups for warm-core convective events west of the Cascades: Type I: Shortwave trough, no onshore flow through depth, southerly surface flow: These "monsoonal plume" kind of events are a part of summer when you get east of the Cascades, but for them to happen in the interior lowlands of W WA or the Willamette Valley, the onshore flow has to be cut off. This is possible if the North Pacific High is located unusually far south and west (closer to the Hawaiian islands), there is robust monsoonal activity (and a mid-level (about 500 hPa) anticyclone) in the Desert Southwest, and a trough is located in the right position. The main danger is wildfires since there is abundant dry lightning. Virga is not uncommon. Examples: September 2-3, 2009; August 2, 2014Type II: Cut off low off the OR/CA coast, no onshore flow through depth, monsoonal moisture: The second primary lifting mechanism for warm-core convective events is a cut off upper level low (cut off meaning it formed independent of the jet stream) spinning off the Oregon coast, which can tap into warmer water off Baja California or a monsoonal trough over land. Couple that with residual heat from a weakening desert high, and you have a recipe for fireworks. As the cells are pushed over the Cascades, high-based lightning becomes more frequent. Examples: August 9-10, 2013; August 11-13, 2014; August 14, 2015Type III: Cut off low off the OR/CA coast, no onshore flow through depth, mid level Pacific moisture: An uncommon cousin of type 2, if there's abundant mid level moisture (like an atmospheric river of the remnants of a Pacific hurricane), you can get drenching thunderstorms that are more characteristic of the Midwest or East Coast. Examples: September 5, 2013; July 20, 2012Type IV: Upper level low churning over E WA: Extremely rare. If there's a closed cut off low located east of the Cascades and sufficient daytime heating, it can push storms east-to-west, forcing them over the Cascade crest and intensifying them. Examples: July 25, 2009 I have attempted to teach myself mesoscale analyses, but I'm having a lot of trouble. I received a lot of great information from the other replies in this thread, but I want to go to the next level, to the quantitative "nitty-gritty". I thought I would start with 8/2/14 since it was the day that that guy recorded himself being struck by lightning on camera. Here's what I have so far, using nullschool.net since I found their dynamic and interactive animations meant it was easier for me to switch heights and times. If you'll indulge me: Thursday, July 31, 11am: An immoving Omega block is over Aluetian Islands. The North Pacific high is unusually south and west, allowing it to tap into the warmer waters of the tropical Pacific, and lead to a bit of an "atmospheric river" effect along the west coast of North America. There's a better shot of the Pacific high at 250 hPa, which also lets you see the vigorous low (~5700dm; try as I might I was unable to find archived barometric pressure map data (using mbar); nor could I find a way to convert geopotential heights into rough barometric pressure) located 950 km off Haida Gwaii. The "river" airflow and the upper level low airflow are converging over the west coast of Vancouver Island. Friday, August 1, 8pm: The shortwave trough starts forming over the interior lowlands of W WA, and a 500 hPa desert high strengthens, intensifying the warm, southerly flow aloft. 700hPa shows the nocturnal low level jet stretching from the Klamath Range all the way to the Willemette Valley. Saturday, August 2A relatively shallow low north of the SF Bay Area steers a jet of moisture towards W WA and OR. Unfortunately, I've become a bit stuck. It was straightforward to get a "big-picture" look from the nullschool visualizations, but I'm not completely satisfied. Nullschool's visualizations only go as far back as 2013-11-01 00Z. Upper air charts on Plymouth State University's website, on the other hand, go back 60 years. The NWS has a large historical archive of surface charts so I'm fine there. I guess what I'm trying to say is, how do I know what to look for? There is so much information that you can map via PSWC: just look at the list! My gut instinct tells me that I should probably get schooled in DIY mesoscale analysis, like through theweatherprediction.com, before I start jumping into charts and whatnot. But, at least you can see what I have so far. If you're still reading so far, the TL;DR is as follows: what would I have to know to write something like this, but for 8/3/99 or 9/5/13 in the Northwest, rather than 4/27/11 in Dixie.
  12. Oh no, it's just out of morbid curiosity. I'm not disagreeing that the products to which I linked are very good. I just found it curious why NOAA archived its charts, but Environment Canada does not. I don't think differences in population would explain it.
  13. Plymouth State University has surface and upper air analysis charts (e.g. soundings) for the United States, and NOAA has archived analysis products stretching back to 1998 through the SPC. Is there an archive of Environment Canada analysis charts available on the internet?
  14. The Weather Channel has this forecast for Seattle tomorrow: which surprised me. I'm used to seeing "rain/thunder" or "t-showers", or "...with a few rumbles of thunder". It made me wonder if TWC has ever forecasted "scattered strong storms", "scattered strong storms/wind", "strong storms", or "strong storms/wind" for the Seattle area. Or anywhere in Washington state for that matter. This also goes for the "a few storms may be severe" or "storms may produce large hail and strong winds" bit.
  15. The weather here has been so darned stable...I never thought I'd say this, but I miss thunderstorms and heat waves. Metro Vancouver and the BC coast used to get a good solid two or three of each, every summer for the past couple of summers. Part of me wishes we could get the dangerous jungle-like heat and wild thunderstorms that are gripping the midwest/northeast right now. But I know that's impossible here because the waters around here are, too cold and the Rockies block any moisture from the Gulf of Mexico. All I can hope for is an active Eastern Pacific hurricane season and the remnants of a wayward hurricane getting tapped into a shortwave, or an upper low. Like the remnants of Hurricane Fabio in 2012. On the other hand, this has been the first stable, PNW-esque summer around here since 2011. Cool temperatures, abundant marine influence, punctuated by a few days of overcast conditions and rain. I'm not begging for air conditioning, the reservoirs are filled, there's no drought, the whole region isn't on fire. Don't look a gift horse in the mouth I guess...
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