May Weather in the Pacific Northwest

[TT-SEA]

Seems we have found ourselves in a typical rudderless May pattern... the marine layer might stay in place for the next 3 or 4 days.   

[Deweydog]

Is it possible to have Tim and Jesse spazzing out over the same pattern?

 

Would that be like crossing the streams?

[Jesse]

Nice evening.

[TT-SEA]

Is it possible to have Tim and Jesse a spazzing out over the same pattern?

 

Would that be like crossing the streams?

 

 

I know right... we are locked in a cloudy and gloomy pattern while everyone is lamenting the heat.   

[Jesse]

I know right... we are locked in a cloudy and gloomy pattern while everyone is lamenting the heat.

It’s been an historically warm and dry month so far, and it looks like it could continue that way after this little marine bump in the road.

 

The past few days have been a nice break.

[Anti Marine Layer]

Seems we have found ourselves in a typical rudderless May pattern... the marine layer might stay in place for the next 3 or 4 days.   

 

In SoCal, they call it May Gray. May and June are the coldest months of the year for the beach locations.

[TT-SEA]

In SoCal, they call it May Gray. May and June are the coldest months of the year for the beach locations.

 

Well aware.

[Jesse]

In SoCal, they call it May Gray. May and June are the coldest months of the year for the beach locations.

Isn’t this your sig?

[Deweydog]

Speaking of coastal California, who knew after all these years it was actually Yanny Canyon?

[Anti Marine Layer]

Anybody remember this one?

 

[TigerWoodsLibido]

Anybody remember this one?

 

GrayDay.jpg

Lovely lipstick

[TT-SEA]

00Z GFS cuts off the trough offshore early next week in just the right spot.   Good compromise.  

[ShawniganLake]

Mostly sunny and 70 here this afternoon. A perfect May afternoon.

[Jesse]

Operational 00z was pretty warm but the ensembles give me hope.

 

[Jesse]

Euro!!!

[VancouverIslandSouth]

Mostly sunny and 70 here this afternoon. A perfect May afternoon.

 

Similar here, there were scattered clouds but it still ended up sunny and the warmth peaked in the evening around 6 - 7pm.

[TT-SEA]

Rain pounding on the roof here.

[Geos]

It's actually raining!

[Jesse]

EPS is still far from buying into any sort of coherent solution beyond day 6.

 

The 06z GFS ensembles trended a bit warmer in the mid range though.

[Phil]

It’s early, but so far, May 2018 is the coldest ever recorded across the Baffin Bay in the JRA55 dataset.

 

Also the 2nd warmest across the lower-48, and 4th warmest across the high Arctic.

[Jesse]

It’s early, but so far, May 2018 is the coldest ever recorded across the Baffin Bay in the JRA55 dataset.

 

Also the 2nd warmest across the lower-48, and 4th warmest across the high Arctic.

Any idea when that feature finally dissipates?

[Phil]

The Atlantic Hadley Cell has retracted way equatorward, almost back to the glory days now.

 

The JMA seasonal continues the trend into summer, while the Pacific Hadley Cell remains bloated and slow.

 

[Phil]

Any idea when that feature finally dissipates?

For M/J/J, we need to reduce off-equator WPAC convection for a sustained reversal.

 

It’s less of an issue for the PNW in A/S/O, though. No correlation to PNW/PNA exists during that period.

 

And come winter the factors governing it are completely different and impossible to see this far in advance. In some winters, the NPAC dominates your wavetrain, and in other years (like last winter) the Siberia/NAO exchanges dominate your wavetrain.

[Jesse]

For M/J/J, we need to reduce off-equator WPAC convection for a sustained reversal.

 

It’s less of an issue in A/S/O. And come winter the factors governing it are completely different and impossible to see this far in advance.

So you don’t know.

[Phil]

So you don’t know.

Correct, I don’t know when it will reverse as an early summer, low frequency background state.

 

I suspect it will likely reverse in August, as it has done this every year since the mid-1990s, before resuming again during the autumn.

 

However, if it doesn’t reverse in August (as some models are suggesting), and we maintain the -AMM/-AMO through the autumn, then that’s a huge break from the last 20+ years of climatology, and would indicate an imminent return to the tropical forcing of the 1960-1990 era, or at least a departure from the 1996-present seasonality of tropical forcing.

 

So in that respect, it could be a good sign if if continues, despite the short term pain it would cause you.

[Phil]

Here’s what I mean. The S/O/N AMM regime has been positive since the mid-1990s.

 

Right now the AMM is very negative..almost -3. If this continues into S/O/N, we’re looking at a very different circulation from the last 20+ years, right when the cold season wavetrain would be developing.

 

[Phil]

The reason I’m skeptical right now is that there’s been no trend in the AMM during A/M/J. Plenty of negative regimes during the spring/early summer during the last 20yrs.

 

Starting during the second half of July, the 1995-present climate regime starts diverging to +AMM, and it’s well established by the second half of August.

 

So if we hold this -AMM through August - November..that would be huge.

[TT-SEA]

12Z GFS is going to be a nice run. I can already tell.

[Phil]

12Z GFS is going to be a nice run. I can already tell.

Will be troughier D10-16, though.

[Jesse]

Will be troughier D10-16, though.

 

Troughing continually getting pushed from the 5-10 day range to the 10-16 day range is a great sign it will never come.

[Jesse]

It kind of boggles the mind to think of how warm this May will end up if the 12Z GFS were to verify verbatim.

 

Basically looking at a June 2015 type of anomaly.

[MossMan]

Only a couple of raindrops so far here this morning.

[TigerWoodsLibido]

Looking like a cloudy day for the kids at the zoo. Twin bros 3rd birthday.

[Phil]

That mid-1990s shift in the late summer circulation is also evident in the EPO. Nice demonstration of the NPAC/NATL relationship on low frequency timescales.

 

 

 

Even though ESRL’s Warm Pool index stops in 2008, you can easily see the connection. WPAC warm pool convective exhaust resonates with and/or amplified a crapload of non-linear feedbacks in the extratropics.

 

[Phil]

FWIW, the reconstructed extrapolations of these indices reveals the well-known sine wave tendency of ocean/atmosphere variability.

 

The amplitudes vary, but the periodicity is usually similar from a spatial perspective. The current wave happens to be very high in amplitude..probably the highest in several centuries.

[Jesse]

FWIW, the reconstructed extrapolations of these indices reveals the well-known sine wave tendency of ocean/atmosphere variability.

 

The amplitudes vary, but the periodicity is usually similar from a spatial perspective. The current wave happens to be very high in amplitude..probably the highest in several centuries.

I don’t think anyone knows what you’re talking about right now, brosef.

[Phil]

I don’t think anyone knows what you’re talking about right now, brosef.

You know what the EPO and warm pool are, correct? I’m also 100% certain you’re familiar with the concept of a simple sine wave.

 

I’m describing the variability of the ocean/atmosphere circulation system, and how said variability emulates a quasi-invariant sine wave structure across time.

[TT-SEA]

Raining fairly hard here.

[TT-SEA]

Nice to see the GEM coming around to a warm holiday weekend.

 

We need to bring the ECMWF around now.

[Geos]

Raining fairly hard here.

 

Those are some pretty heavy returns just over the pass.