May 2019 Weather Discussion PNW

[Deweydog]

May the 24th be with you!!!

[jcmcgaffey]

Rain pounding on the roof woke me up at some point around 3am or so...must have been brief as the rain gauge registered .02”.

Woke up to rain this morning here as well. It was very refreshing but that convergence has been consistent lately.

[TacomaWaWx]

Has done some sprinkles this morning but nothing in the way of rainfall here. Currently 53 degrees.

[SilverFallsAndrew]

Was some blessed rain falling this morning when I left for work.

[MossMan]

Dribbling drizzle here currently.

[Geos]

Impressive thunderstorm in central Snohomish County tonight. Lots of lightning detected. Saw some and heard some thunder.

 

Wish I would have seen that!

Total crazy bipolar weather. From 76 yesterday to 53 right now with drizzle. 

[SilverFallsAndrew]

Raining now on the river in Salem. 

[TigerWoodsLibido]

Some decent rain this morning. Glad I got the yard work done yesterday.

[Geos]

Nothing is yellow or brown here yet, despite the drought. Been mowing the grass consistently this spring. If we get these short spells of rain once a week the vegetation will stay happy. 

[Omegaraptor]

The grass is starting to look a bit yellow but I don’t think it’s as bad as last year.

[TT-SEA]

12Z ECMWF still showing much warmer and drier weather for Sunday and Monday.   

 

And basically keeps it dry and warm through the end of the run.   The last couple runs had a trough moving in by day 8... but the new run is ridgy even at day 10.

 

[Phil]

12Z ECMWF still showing much warmer and drier weather for Sunday and Monday.

 

And basically keeps it dry and warm through the end of the run. The last couple runs had a trough moving in by day 8... but the new run is ridgy even at day 10.

 

FWIW, to me that looks like a clear error over the Pacific after D6 (referencing the handling of the GOA trough).

 

You would not expect the positive tilt and overall slowdown in flow at that stage, but that’s a typical ECMWF bias.

 

It could be right, but I’d be wary of it.

[TT-SEA]

FWIW, to me that looks like a clear error over the Pacific after D6 (referencing the handling of the GOA trough).

 

You would not expect the positive tilt and overall slowdown in flow at that stage, but that’s a typical ECMWF bias.

 

It could be right, but I’d be wary of it.

 

 

No kidding.

[Phil]

No kidding.

BTW, can you see the crazy disagreement within the EPS now? It’s nuts.

 

I figure last night’s 00z is perhaps the most demonstrative example of state dependent chaos we’ve seen yet. The solution is useless after D8 because there is essentially no structural homogeneity between members.

[TT-SEA]

BTW, can you see the crazy disagreement within the EPS now? It’s nuts.

 

I figure last night’s 00z is perhaps the most demonstrative example of state dependent chaos we’ve seen yet. The solution is useless after D8 because there is essentially no structural homogeneity between members.

Not really that interested in each member. I just track the mean and its been fairly consistent. We will see.

[Phil]

Not really that interested in each member. I just track the mean and its been fairly consistent. We will see.

Consistent? I don’t see any consistency.

 

I made an animated gif of the last several runs to display the variances. Let me pull it up.

[TT-SEA]

Consistent? I don’t see any consistency.

 

I made an animated gif of the last several runs to display the variances. Let me pull it up.

 

 

Whatever dude.     

 

I don't have time to get into a Phil-debate this afternoon.   

[TacomaWaWx]

Consistent? I don’t see any consistency.

 

I made an animated gif of the last several runs to display the variances. Let me pull it up.

the models have been a bit inconsistent (all of them in general) with forecasting this weekend. Feels like late February again when we were waiting to see if Oregon or Washington was going to get pounded with snow and it ended up being Eugene.

[SilverFallsAndrew]

Overall this is pretty typical late May weather. We've had precip for about 10 days in a row now, but not even 2" total. It can be much worse. I came of age in the late 1990s, there were some very wet Memorial Day weekends in there. 

[TacomaWaWx]

Only 54 degrees as of 12:30pm. Has done light drizzle on and off but not enough to even make the ground wet.

[Omegaraptor]

Phil, any thoughts on analogs now that the ENSO is floundering?

[Omegaraptor]

If the NAM is right, tomorrow could actually be the coldest May 25 on record at PDX.

[TT-SEA]

If the NAM is right, tomorrow could actually be the coldest May 25 on record at PDX.

 

 

12Z ECMWF shows 57 at PDX tomorrow... and then back into the 70s on Sunday.   

[Timmy Supercell]

Overall this is pretty typical late May weather. We've had precip for about 10 days in a row now, but not even 2" total. It can be much worse. I came of age in the late 1990s, there were some very wet Memorial Day weekends in there. 

 

The latter half of May is even a little cooler than average in spots like my location. The warmth we had earlier may not even make a big difference.

 

Yeah sometimes very wet Memorial Weekends we've seen, but a few of them resulted from t'storm events like the one in 2008, which was probably one of the most exciting Portland Metro t'storms until June 2009.

[Timmy Supercell]

We're fast approaching the 10th anniversary of one of the most impressive storm events west of the cascades in almost 2 weeks (both in terms of areal coverage and severity). That'd be a worthy event to discuss on the historical wx events post we have on this forum. PDX itself didn't have a good one really, but most locations south of this had a legit good one, and probably everybody along the I5 stretch including the coastline recorded thunder that day.

[TT-SEA]

00Z EPS starting to show another jet extension in the 10-15 day period... and farther north than the last one.

 

This is the 10-15 day mean... but it seems to be retrograding by the end of the run as 500mb heights and 850mb temps are above normal again by day 15.

 

Looks like a wetter pattern than the last one for the PNW.

 

 

12Z EPS agrees well its previous run. Here is the new 10-15 day mean...

 

 

 

This is consistency in my book... despite Phil saying its swinging wildly around just to argue.

 

Its a couple days faster than the operational run... and in agreement overall with its previous run. And it also shows it retrograding by the end of the run again.

 

Here is day 15...

 

 

 

Phil will now tell us that the 10-15 day mean from the 00Z run is completely different than the 10-15 day mean from the 12Z run. Totally opposite. Even though they almost identical to me.

[Omegaraptor]

Why is there more convective activity in May/June than any other time of year in the PNW?

 

In parts of Eastern OR/WA there’s even a precipitation spike in those months. What explains it?

[TigerWoodsLibido]

the models have been a bit inconsistent (all of them in general) with forecasting this weekend. Feels like late February again when we were waiting to see if Oregon or Washington was going to get pounded with snow and it ended up being Eugene.

 

I approve this message.

[TT-SEA]

Why is there more convective activity in May/June than any other time of year in the PNW?

 

In parts of Eastern OR/WA there’s even a precipitation spike in those months. What explains it?

 

Combination of more sun energy and lingering cold air masses thanks to seasonal lag.

[Requiem]

We're fast approaching the 10th anniversary of one of the most impressive storm events west of the cascades in almost 2 weeks (both in terms of areal coverage and severity). That'd be a worthy event to discuss on the historical wx events post we have on this forum. PDX itself didn't have a good one really, but most locations south of this had a legit good one, and probably everybody along the I5 stretch including the coastline recorded thunder that day.

PDX definitely had a decent storm (if of course we’re talking about the 6/4/9 thunderstorm), with wind gusts 45-60 and heavy rain in some areas. Not as much lightning as some areas, but still...

[TacomaWaWx]

I approve this message.

I was kind of disappointed when that one went south at first instead of hitting us but now that I think about it probably wouldn’t have been good. We still had a little snow on the ground here but many other areas still had deep snow away from the sound. Plus the Oregon posters were able to get in on the craziness.

[BLI snowman]

Why is there more convective activity in May/June than any other time of year in the PNW?

 

In parts of Eastern OR/WA there’s even a precipitation spike in those months. What explains it?

 

Stronger sun angles than early spring with warmer temps aloft, frequent cut-off low activity, and fairly transient 500mb patterns as opposed to the more stable Four Corners/NE Pacific high pressure driven regime of mid-summer.

 

Cold core thunderstorm activity requires strong upper level troughing, and warm core thunderstorm activity requires diffluence resulting from an upper level trigger overriding offshore flow. May and June is the time of year where we can easily see both, along with September. 

[Requiem]

I was kind of disappointed when that one went south at first instead of hitting us but now that I think about it probably wouldn’t have been good. We still had a little snow on the ground here but many other areas still had deep snow away from the sound. Plus the Oregon posters were able to get in on the craziness.

And plus you already has a ton of snow the week earlier anyways, so...

[TacomaWaWx]

And plus you already has a ton of snow the week earlier anyways, so...

Yeah it wasn’t really a big deal missing out. We had another 1.5” of snow in March too. Was a legendary winter already without the extra foot of snow.

[Phil]

12Z EPS agrees well its previous run. Here is the new 10-15 day mean...

 

 

 

This is consistency in my book... despite Phil saying its swinging wildly around just to argue.

 

Its a couple days faster than the operational run... and in agreement overall with its previous run. And it also shows it retrograding by the end of the run again.

 

Here is day 15...

 

 

 

Phil will now tell us that the 10-15 day mean from the 00Z run is completely different than the 10-15 day mean from the 12Z run. Totally opposite. Even though they almost identical to me.

Remember this?

 

Side note... the EPS basically shows 850mb temps above normal for the next 14 straight days with the exception of Friday afternoon.

 

This will be a very brief interlude of warmer weather before we get back to default cold and troughing.

EPS shows one of those very brief ridges that Phil talks about... this one might only last 12 days. Blink and you will miss it.

10-15 day mean:

 

Well, I read through the page above. I admit I lol’ed.

 

Ordinarily I’d respond, but I think I’ll let this play out, then bump a few posts down the road. I’ve already karma’d myself into a massive pre-Memorial Day SE-Ridge, which seemed to magically appear on the models right when I started trolling Tim. I won’t risk prolonging it.

[TT-SEA]

Remember when it was showing 14 consecutive days with warmer than average 850mb temps?

 

Oh, Tim.

 

Oh wait... so time moves forward?  

 

You mean every single run has to be exactly the same or its worthless?  

[TT-SEA]

Remember this?

 

 

 

You just proved my point!   Here is the map that I posted 3 days ago for the 10-15 day period.   You just re-posted this above.   

 

 

 

And here is the new 12Z EPS for the EXACT same period:

 

 

 

Pretty darn consistent.   Obviously the anomalies become more defined as we move in closer.

 

You do understand that time moves forward right?    The 10-15 day period on Tuesday is a different period than the 10-15 day period today.   

[Phil]

Silly, silly Tim.

 

EPS mean, same date. “Consistent” my a**.

 

[TT-SEA]

EPS mean, same date, changes over 5 days.

 

“Consistent” my a**.

 

 

 

You are comparing one run to another run at a specific time.   

 

You will always be able to find exceptions.   The blended mean has been very consistent.    You just love to argue.        

[Phil]

Oh, so now there are exceptions? How many exceptions? How often do they happen?

 

Translated: The EPS is consistent, except for when it’s not consistent (or when it doesn’t show the outcome I want).