PNW April 2023 Weather Discussion

[TT-SEA]

9 minutes ago, Meatyorologist said:

Keep in mind those numbers are relative to the updated 1991-2020 normals. While this current April is depicted to be running around -4.2F, compared to +5.4F in 2016, its actual climatological variance is skewed. In our pre-industrial world this April would be chilly no doubt, but closer to a more reasonable 2-3F below normal. The opposite effect would be had on April 2016's anomaly, boosting it to 7-8F above the long term average.

Agreed... but the pre-industrial world was still coming out of the LIA.   Maybe April 2016 was normal back in the Medieval Warm Period?    But then this month would be crazy warm in terms of normal during the last ice age.    So what is normal in an ever changing climate?

How awesome would it be to have daily weather data for Seattle going back 15,000 years.    What was April 12, 1175 like?   Or April 12, 800 BC?   It would be endlessly fascinating compared to the boring 140 years of data that we do have.  

[SilverFallsAndrew]

When I was looking at the state data in Oregon since 1895, April is the month with the least change. The average April temp has warmed less than 1F in that time compared to nearly 5F in January. 

[Phil]

1 hour ago, TT-SEA said:

Yeah... its pretty strange.   It should not be this hard to accidentally get a warm a day into between troughs by this point.    The extreme persistence of the cold makes me think summer might be more persistently warm than some are expecting.   Last spring we were talking about 1999 and 2011 as analogs.    But nature had other plans.

If that logic were valid, 2014 and 2015 would’ve had cold summers, while 2011 and 1999 would’ve had hot summers.

It doesn’t actually work that way at all.

[TT-SEA]

4 minutes ago, Phil said:

If that logic were valid, 2014 and 2015 would’ve had cold summers, while 2011 and 1999 would’ve had hot summers.

It doesn’t actually work that way at all.

Nope... not saying it normally works that way.   That is the point.    I am saying this is starting to feel like last spring in terms of persistence of the pattern.   Which makes me think of the extreme offset we saw last summer which defied all predictions.

[SilverFallsAndrew]

4 minutes ago, Phil said:

If that logic were valid, 2014 and 2015 would’ve had cold summers, while 2011 and 1999 would’ve had hot summers.

It doesn’t actually work that way at all.

Given where we were on the ENSO cycle it would have made sense to have expected 2022 to have followed 2011 or 1999 more or less. 

2011 was a nice summer, coolish July and average August. Very warm (at the time) September. 

[SilverFallsAndrew]

1 minute ago, TT-SEA said:

Nope... not saying it normally works that way.   That is the point.    I am saying this is starting to feel like last spring in terms of persistence of the pattern.   Which makes me think of the extreme offset we saw last summer which defied all predictions.

It's possible we could see the same flip. We'll see, if we don't have as much persistence of the 4CH this summer, as Phil is positing, then we may see a much different pattern evolution. The CANsips is interesting as it shows a pretty average May-July period west of the Cascades, with positive anomalies building in from Seattle-north by July and a fairly warm July in SW BC. 

August is more regionally warm, though near average for most of Western and south central Oregon. It shows September being a pretty warm month.

An early look at the next cold season appears front loaded with normal to slightly below normal temps through January and then well above average temps in February/March. Precip for the most part looks below average. 

[Cascadia_Wx]

Cold, rainy and wintery this morning with even some wet snow mixed in at times, but sunny, puffy clouds and mild feeling out this afternoon. 52/36 day here so far.

[Cold Snap]

Jay says that ENSO forecasts are pretty useless right now.

[MossMan]

52/30 on the day. Currently 47. Met a friend at their house near Big Lake to walk the dogs in their extensive walking trails in the woods this afternoon, was a perfect day for it! 

[T-Town]

More cloudscapes tonight. 

[Cloud]

20 minutes ago, Cold Snap said:

Jay says that ENSO forecasts are pretty useless right now.

We’re basically at 0 now. Niño is certain at this point. 

[Anti Marine Layer]

It's amazing when January continues into April, but it would be A-May-zing if January lasted into May.

[Meatyorologist]

54 minutes ago, TT-SEA said:

Agreed... but the pre-industrial world was still coming out of the LIA.   Maybe April 2016 was normal back in the Medieval Warm Period?    But then this month would be crazy warm in terms of normal during the last ice age.    So what is normal in an ever changing climate?

How awesome would it be to have daily weather data for Seattle going back 15,000 years.    What was April 12, 1175 like?   Or April 12, 800 BC?   It would be endlessly fascinating compared to the boring 140 years of data that we do have.  

This would be an autism information hazard. I'd entrap myself scrolling through that dataset for days consecutively.

In the last 15000 years, I'll go with a 114/-32 spread for KSEA. Lots of climate variance, and I'm sure there's plenty of room for a stretch of heatwave-favored years. Just back to 1950 we have a 108/0 spread; almost all the way there on the top end.

Given that the Puget Sound basin was a parkland/tundra type environment 15000 years ago, I think -32F could have happened with the right airmass.

[GHweatherChris]

11 minutes ago, Cloud said:

We’re basically at 0 now. Niño is certain at this point. 

But we prob won't see any meaningful impact of any kind for several months.  One big indicator will be on the coast, just speaking anecdotally Nino summers when I was younger living in Westport we would go days without sun breaking through, no precip just lots of low clouds and fog but just a few miles inland it would be mostly sunny and nice.  But if I remember correctly that was usually the summer after Nino would settle in. 

[Cascadia_Wx]

2 hours ago, SilverFallsAndrew said:

38 days now with measurable snowfall since November 1st. Today is the 4th day this month, twice as many as we saw in January... Of course...

Good job Andrew.

[SilverFallsAndrew]

1 minute ago, Cascadia_Wx said:

Good job Andrew.

WE DID IT!

[Cloud]

8 minutes ago, GHweatherChris said:

But we prob won't see any meaningful impact of any kind for several months.  One big indicator will be on the coast, just speaking anecdotally Nino summers when I was younger living in Westport we would go days without sun breaking through, no precip just lots of low clouds and fog but just a few miles inland it would be mostly sunny and nice.  But if I remember correctly that was usually the summer after Nino would settle in. 

That’s how it typically works. And I don't expect an immediate impact either.  Furthermore, we experienced a rare triple Niña, so it's difficult to know what kind of impact going forward.

 

[GHweatherChris]

7 minutes ago, Cascadia_Wx said:

Good job Andrew.

Just an all around team effort, well done!!

[T-Town]

One more. 

[Anti Marine Layer]

11 minutes ago, SilverFallsAndrew said:

WE DID IT!

[Cold Snap]

45 minutes ago, Cloud said:

We’re basically at 0 now. Niño is certain at this point. 

Yeah Nino is certain but how strong the Nino becomes is still a huge question I feel like.

[Cloud]

3 minutes ago, Cold Snap said:

Yeah Nino is certain but how strong the Nino becomes is still a huge question I feel like.

Agreed. I would love for a weak Niño or neutral. I think neutral years tends to be quite good around here. 

[GHweatherChris]

13 minutes ago, Cloud said:

Agreed. I would love for a weak Niño or neutral. I think neutral years tends to be quite good around here. 

Knowing that we most likely can be assured of 1 or 2 beefy heat spikes in the summers now, my only hope is we can hit that right combo of 1 regionally historical winter in regards to snowfall and cold, old school style.

[Cascadia_Wx]

Such a gorgeous spring evening out there.

[FroYoBro]

Just now, Cascadia_Wx said:

Such a gorgeous spring evening out there.

Yep. Lots of sexual energy out there. 

[GHweatherChris]

1 minute ago, FroYoBro said:

Yep. Lots of sexual energy out there. 

[Cascadia_Wx]

4 minutes ago, FroYoBro said:

Yep. Lots of sexual energy out there. 

It’s almost palpable!!

[Cloud]

8 minutes ago, Cascadia_Wx said:

Such a gorgeous spring evening out there.

Gorgeous day up here in general. Allowed me to set up our security system and a little bit of yard work in as well

[Cascadia_Wx]

6 minutes ago, Cloud said:

Gorgeous day up here in general. Allowed me to set up our security system and a little bit of yard work in as well

Now you can check if Jim is sneaking into your yard and tearing leaves off your plants in the fall.

[Cloud]

3 minutes ago, Cascadia_Wx said:

Now you can check if Jim is sneaking into your yard and tearing leaves off your plants in the fall.

I disagreed with him on so many stuff weather related he might just

[MossMan]

6 minutes ago, Cloud said:

I disagreed with him on so many stuff weather related he might just

Hope Jim, Kayla, and Brian in Leavenworth are all doing well. 
Along with Anthony and Mallow The Cloud. 

[Cascadia_Wx]

4 minutes ago, MossMan said:

Hope Jim, Kayla, and Brian in Leavenworth are all doing well. 
Along with Anthony and Mallow The Cloud. 

[Skagit Weather]

1 hour ago, Meatyorologist said:

This would be an autism information hazard. I'd entrap myself scrolling through that dataset for days consecutively.

In the last 15000 years, I'll go with a 114/-32 spread for KSEA. Lots of climate variance, and I'm sure there's plenty of room for a stretch of heatwave-favored years. Just back to 1950 we have a 108/0 spread; almost all the way there on the top end.

Given that the Puget Sound basin was a parkland/tundra type environment 15000 years ago, I think -32F could have happened with the right airmass.

I was going to suggest that the minimum temperature must have been lower with the ice sheet on top of us, but I didn't realize it retreated 16,000 years ago right before the period you're discussing. For that time during the glaciation it looks like temperatures were estimated to be 5-7ºC (9-12ºF) colder than today with about a quarter the precipitation. Here's the paper that discusses the plants and the climate around that time.

It also mentions the climate as the glaciers began to retreat 14-16,000 years ago. Supposedly temperatures were 2-6ºC (3-10ºF) colder than today and precipitation was similar to today in the PNW as the Laurentide ice sheet shrank in the middle of the country and the jet stream (which had split leading to drier conditions in the PNW during the height of the ice sheets) became more consolidated.

[Timmy]

Emergency closure of the Lewis and Clark bridge (rainier/Longview) https://www.kptv.com/2023/04/13/longview-bridge-closes-emergency-repairs-traffic-detours-portland-coast/

[SnowySeeker50]

Intense hail shower here in Federal Way

[Phil]

3 hours ago, Meatyorologist said:

This would be an autism information hazard. I'd entrap myself scrolling through that dataset for days consecutively.

In the last 15000 years, I'll go with a 114/-32 spread for KSEA. Lots of climate variance, and I'm sure there's plenty of room for a stretch of heatwave-favored years. Just back to 1950 we have a 108/0 spread; almost all the way there on the top end.

Given that the Puget Sound basin was a parkland/tundra type environment 15000 years ago, I think -32F could have happened with the right airmass.

-32°F is conservative on the low end. The climate over the North American ice sheets during glacial maximum was on par with that of Antarctica today.

It snowed in midsummer over what is now the Puget Sound basin.

[SilverFallsAndrew]

If it snowed in mid summer then how did the 1% go water skiing on lake Sandwich? 

[MossMan]

Down to 34

[Anti Marine Layer]

9 minutes ago, SilverFallsAndrew said:

If it snowed in mid summer then how did the 1% go water skiing on lake Sandwich? 

They were protected by the top half of the sandwich. 

[TT-SEA]

25 minutes ago, SilverFallsAndrew said:

If it snowed in mid summer then how did the 1% go water skiing on lake Sandwich? 

That is what created Lake Sandwich!  And Lake Warshington.