April 2024 Weather in the PNW

[TigerWoodsLibido]

Why does the forecast discussion not mention the possibility of 0.25" of rain here in this part of the NWS Portland forecast zone?

[Front Ranger]

2 minutes ago, DeepFriedEgg said:

I think most of that is due to the persistent la Nina since 2017. We should have been running pretty significantly wetter and colder than normal, but it ended up being normal temps.

February and March are the months with the strongest statistical correlation to ENSO. That period has run significantly below normal since 2017. Not wetter than normal, though.

[TT-SEA]

5 minutes ago, DeepFriedEgg said:

I think most of that is due to the persistent la Nina since 2017. We should have been running pretty significantly wetter and colder than normal, but it ended up being normal temps.

I would not say Nina has been persistent since 2017.   The Nina effect was in full gear in 2022 and 2023 and those Aprils did end up colder and much wetter than normal.   

[Meatyorologist]

28 minutes ago, TT-SEA said:

So focusing on just April... since 2017 Portland has averaged 3.26 inches of rain in April compared to the long term average of 2.53 inches.   Significantly wetter than average.   

Also in Portland since 2017... April has averaged 52.8 degrees compared to normal of 52.8 degrees.  Exactly normal overall in recent years.   In addition... the last 2 years April was colder and much wetter than normal. 

I think its more of the usual irrational doom and gloom to say April is becoming more of a summer month in recent years.   Its been normal in terms of temps and quite a bit wetter than normal in terms of precip.   

Those are just straight statistics.   Not much room for debate there.  

 

 

 

I don't want to pour gasoline on the fire, but you are pretty conveniently cutting off April 2016 and it's juicy 90-burger. Just peep at that spike, yowzers!

But looking at the graph again, you can see we're simply making up for the dip during the 2000s, amidst an overall warming trend since records began. We're probably just oscillating back into a slightly shallower low point than the 2000s dip. April might be a little cooler for the next decade. Or probably not. Who knows.

[TT-SEA]

3 minutes ago, Meatyorologist said:

I don't want to pour gasoline on the fire, but you are pretty conveniently cutting off April 2016 and it's juicy 90-burger. Just peep at that spike, yowzers!

But looking at the graph again, you can see we're simply making up for the dip during the 2000s, amidst an overall warming trend since records began. We're probably just oscillating back into a slightly shallower low point than the 2000s dip. April might be a little cooler for the next decade. Or probably not. Who knows.

Recent years in arbitrary of course.     2015 and 2016 were crazy warm Nino springs.    Since then there has not been much of trend at all.

[Cascadia_Wx]

Radar is looking fairly active down the valley.

[Rubus Leucodermis]

59.2˚F.

[BLI snowman]

I think there is some conflation with "spring" and April. Spring also includes May, which has seen a distinct tendency towards warmer + drier than average since 2015. Including a solid handful of Mays in that timeframe (2015, 2016, 2018, 2019, 2021, 2023) where it effectively didn't rain the whole month across wide swaths of the region. You expect one or two of those per decade but the pace has really accelerated recently.

The early part of spring has been pretty distinct from the latter part of spring when it comes to the departures from average, since March and April haven't seen a sharp statistical trend in that direction but May and early June (still more spring climo-wise) definitely have.

[Cascadia_Wx]

2 minutes ago, BLI snowman said:

I think there is some conflation with "spring" and April. Spring also includes May, which has seen a distinct tendency towards warmer + drier than average since 2015. Including a solid handful of Mays in that timeframe (2015, 2016, 2018, 2019, 2021, 2023) where it effectively didn't rain the whole month across wide swaths of the region. You expect one or two of those per decade but the pace has really accelerated recently.

The early part of spring has been pretty distinct from the latter part of spring when it comes to the departures from average, since March and April haven't seen a sharp statistical trend in that direction but May and early June (still more spring climo-wise) definitely have.

Exactly. And in many recent years, that warm and dry tendency has even bled into the latter half of April. Which was my point all along.

Of course, monthly stats don’t always capture this. For example, a statistically cool and wet April like last year still had summer like conditions start in earnest the last week of the month, and after that we never really looked back.

[Front Ranger]

6 minutes ago, BLI snowman said:

I think there is some conflation with "spring" and April. Spring also includes May, which has seen a distinct tendency towards warmer + drier than average since 2015. Including a solid handful of Mays in that timeframe (2015, 2016, 2018, 2019, 2021, 2023) where it effectively didn't rain the whole month across wide swaths of the region. You expect one or two of those per decade but the pace has really accelerated recently.

The early part of spring has been pretty distinct from the latter part of spring when it comes to the departures from average, since March and April haven't seen a sharp statistical trend in that direction but May and early June (still more spring climo-wise) definitely have.

The conversation started with someone talking about summer starting in April. That's where the stats shared have been focused. 

[Cascadia_Wx]

We’ll see if this year, with generally warm temps and plentiful 70s starting in mid March, follows a similar trend, or things flip back at some point before we embark on our true warm and dry season. Obviously the latter would be much better for our local ecology, wildfire concerns, etc. But these days, I never take a the return of a wet pattern for granted after late April.

[DareDuck]

1 hour ago, TigerWoodsLibido said:

Why does the forecast discussion not mention the possibility of 0.25" of rain here in this part of the NWS Portland forecast zone?

Mainly mild and dry conditions across the north, with scattered showers lingering over the Cascades and south
Willamette Valley through Saturday

[Meatyorologist]

At its core, it's a 4CH issue. Something about the decaying Niño and the wonderful state the current western US snowpack situation is in gives me some hope we might be able to avoid a bloated western ridge via thermal heating runaway.

2019 would have been a cool summer if it weren't for the ridge that popped overhead mid July-September. It was a wasted opportunity, the only other opportunity we've had since 2012.

[Blizzard777]

5 hours ago, SilverFallsAndrew said:

Someday when work slows down and the kids are a little older I want to do a 2 week camping trip To Utah. These drive bys don’t really do it justice. 

Once you get out there exploring you really don’t want to come back! So much to see and do. Utah is beautiful

[BLI snowman]

2 minutes ago, Front Ranger said:

The conversation started with someone talking about summer starting in April. That's where the stats shared have been focused. 

Recently I would say that the "start" of summer, if we're defining that as reliably sunny, warm, and dry weather, has broadly coincided with the annual death of the polar jet across the CONUS, which is usually at the very end of April or during the first half of May.

Whereas in historic terms the PNW often keeps the cut-off low factory going well enough into June that spring-like climo still persists, with cooler temps and showery weather hanging around. Anecdotally it just feels like those patterns during that stretch of calendar have had a lot less teeth in the last decade while also being a little fewer and further between. Perhaps owing to the stronger flexing of the 4CH. In any case it seems pronounced enough to be a trend and it does feel like it correlates pretty soundly with our midsummer climate changes.

[Front Ranger]

18 minutes ago, BLI snowman said:

I think there is some conflation with "spring" and April. Spring also includes May, which has seen a distinct tendency towards warmer + drier than average since 2015. Including a solid handful of Mays in that timeframe (2015, 2016, 2018, 2019, 2021, 2023) where it effectively didn't rain the whole month across wide swaths of the region. You expect one or two of those per decade but the pace has really accelerated recently.

The early part of spring has been pretty distinct from the latter part of spring when it comes to the departures from average, since March and April haven't seen a sharp statistical trend in that direction but May and early June (still more spring climo-wise) definitely have.

Also, you're looking mainly at precip here. Temps are a large part of the discussion as well.

Where you draw the line matters, of course. 2015 and 2016 alter the discussion for May from 2017, and if you go back to 2013 or further it also changes. 

[Blizzard777]

1 hour ago, TT-SEA said:

Meanwhile... down in CA where mid-April is usually the start of the reliably dry season people are wondering why its still winter.    Reservoirs are full and its dumping rain... all despite global warming.    

Just a beautiful looking storm

[Front Ranger]

4 minutes ago, BLI snowman said:

Recently I would say that the "start" of summer, if we're defining that as reliably sunny, warm, and dry weather, has broadly coincided with the annual death of the polar jet across the CONUS, which is usually at the very end of April or during the first half of May.

Whereas in historic terms the PNW often keeps the cut-off low factory going well enough into June that spring-like climo still persists, with cooler temps and showery weather hanging around. Anecdotally it just feels like those patterns during that stretch of calendar have had a lot less teeth in the last decade while also being a little fewer and further between. Perhaps owing to the stronger flexing of the 4CH. In any case it seems pronounced enough to be a trend and it does feel like it correlates pretty soundly with our midsummer climate changes.

Sure. And I think you'd also agree with my point that the early part of the warm season hasn't seen near the level of warming as the heart of summer. September either, for that matter. 

[Meatyorologist]

8 minutes ago, BLI snowman said:

Recently I would say that the "start" of summer, if we're defining that as reliably sunny, warm, and dry weather, has broadly coincided with the annual death of the polar jet across the CONUS, which is usually at the very end of April or during the first half of May.

Whereas in historic terms the PNW often keeps the cut-off low factory going well enough into June that spring-like climo still persists, with cooler temps and showery weather hanging around. Anecdotally it just feels like those patterns during that stretch of calendar have had a lot less teeth in the last decade while also being a little fewer and further between. Perhaps owing to the stronger flexing of the 4CH. In any case it seems pronounced enough to be a trend and it does feel like it correlates pretty soundly with our midsummer climate changes.

Never thought about the inception of our annual warm season in that way. Good insight.

[Cascadia_Wx]

1 minute ago, Front Ranger said:

Sure. And I think you'd also agree with my point that the early part of the warm season hasn't seen near the level of warming as the heart of summer. September either, for that matter. 

This seems like an unnecessary and kind of no brainer side point. Introduced mainly to distract from/water down the veracity and significance of the original point in the name of “nuance” and “providing context”.

Hi Flatiron!

 

[BLI snowman]

1 minute ago, Front Ranger said:

Sure. And I think you'd also agree with my point that the early part of the warm season hasn't seen near the level of warming as the heart of summer. September either, for that matter. 

August is definitely kind of its own runaway freight train at this point, but the whole May-August stretch has seen that broad shift towards warmer and drier. September is interesting in that it's at least maintained some productivity from a precip POV, perhaps owing to the inescapable change in wavelengths at that point which can reliably stick a few bullets in the summer pattern.

[MossMan]

Absolutely lovely day. 

[TT-SEA]

Landscape starting to take on the summer look.   Just drove from North Bend to Bellevue and the trees are uniformly at about the same stage on that drive... about the same in NB as in Bellevue.

[BLI snowman]

13 minutes ago, Front Ranger said:

Also, you're looking mainly at precip here. Temps are a large part of the discussion as well.

Where you draw the line matters, of course. 2015 and 2016 alter the discussion for May from 2017, and if you go back to 2013 or further it also changes. 

Really only May 2022 stands out as cooler than average since 2015. May 2021 was fairly average temp-wise but also was consistently sunny and dry as a bone. Several historically warm Mays in that stretch as well.

[Port Angeles Foothiller]

Bout to start getting pretty dry around this area.

[Front Ranger]

29 minutes ago, BLI snowman said:

August is definitely kind of its own runaway freight train at this point, but the whole May-August stretch has seen that broad shift towards warmer and drier. September is interesting in that it's at least maintained some productivity from a precip POV, perhaps owing to the inescapable change in wavelengths at that point which can reliably stick a few bullets in the summer pattern.

No doubt. 

Just like there's nuance in the spring trend talk (early vs late), same applies to overall warm season. 

[Meatyorologist]

It would be totally on theme to run a -4F at KPDX this August after all this talk.

[SilverFallsAndrew]

3 hours ago, Cascadia_Wx said:

It’s semantics, so definitely up your alley, but generally dry, warm, summer like conditions certainly started in April in 2018 and 2019. Very warm Mays both those years and near to above normal Junes. A few rainy downturns later in May or June didn’t do a whole to dampen the summer vibez  (unless you’re Dewey  )

2017 was a decent late Spring but we paid for it with drought and fire later on. Same with 2020, averagish May and June so it was of course answered with late summer hellstorms. Point is we can never win.

I was going to say: I distinctly remember the summer dry season starting around April 20, 2018. Freakishly dry May. 

[Cascadia_Wx]

6 minutes ago, Meatyorologist said:

It would be totally on theme to run a -4F at KPDX this August after all this talk.

We’ve probably had a dozen or more iterations of this exact same discussion over the years and August keeps getting hotter.

Jinx’s and superstition don’t do a lot to circumvent a rapidly warming region/planet, sadly

[Front Ranger]

1 hour ago, Cascadia_Wx said:

This seems like an unnecessary and kind of no brainer side point. Introduced mainly to distract from/water down the veracity and significance of the original point in the name of “nuance” and “providing context”.

Hi Flatiron!

 

Nah, there has been conflation of the warm season and summer itself.

It was more a point showing that I have no issue acknowledging the parts of the warm season that have been historically warm and dry.

And back to the original point, that does not include April.

[Frontal Snowsquall]

2 hours ago, TigerWoodsLibido said:

Why does the forecast discussion not mention the possibility of 0.25" of rain here in this part of the NWS Portland forecast zone?

Some good moisture is about to move into the PDX Metro area. It’s moving NW so the bulk of the moisture might miss PDX though.

[Cascadia_Wx]

4 minutes ago, Frontal Snowsquall said:

Some good moisture is about to move into the PDX Metro area. It’s moving NW so the bulk of the moisture might miss PDX though.

God willing!

[TigerWoodsLibido]

Gettin' close to 0.5" of rain today. Very nice!! Keep this up thru June so we keep fires more manageable.

[Cascadia_Wx]

68, mostly cloudy and dry here…

….

[SilverFallsAndrew]

Severe thunderstorm in Klamath County 

[ShawniganLake]

64/33 here so far today.  It was frosty this morning 

[T-Town]

HCS keeping temps suppressed here, sitting at 59 at the moment. 

[SilverFallsAndrew]

[MossMan]

HCS is ruining my deck sunning session.

[Front Ranger]

37 minutes ago, TigerWoodsLibido said:

Gettin' close to 0.5" of rain today. Very nice!! Keep this up thru June so we keep fires more manageable.

The Eugene/Springfield firestorm apocalypse may have to wait yet another year.