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May 2017 Observations and Model Discussion for the Pacific Northwest


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00Z ECMWF shows low 90s in Portland on Monday and Tuesday. Nothing screams a June crash more than late May heat.

 

Yeah, it is historically tough to see late May heat really bleed into June by much. However, as has been discussed, there's no such strong signal for it continuing well into summer. 

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What causes record lows (night time) in the warm seasons?  KSLE has a record low of 32F in June and I find that hard to believe more like station error? And 35F for July as well.  What on earth would cause these kinds of conditions?   Any expert opinions/thoughts on this?   I don't think radiational cooling is the entire answer.

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Last night's Euro and today's 12z GFS definitely water down the "crash" a little.

 

 

Yay.   This might not happen guys!!   

 

(sarcasm)

**REPORTED CONDITIONS AND ANOMALIES ARE NOT MEANT TO IMPLY ANYTHING ON A REGIONAL LEVEL UNLESS SPECIFICALLY STATED**

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12Z ECMWF sliding east... GFS and GEM went the other way and were more robust.

 

http://www.tropicaltidbits.com/analysis/models/ecmwf/2017051912/ecmwf_z500_mslp_namer_7.png

**REPORTED CONDITIONS AND ANOMALIES ARE NOT MEANT TO IMPLY ANYTHING ON A REGIONAL LEVEL UNLESS SPECIFICALLY STATED**

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This would be a spectacular Memorial Day weekend... goldilocks weather.  :)

 

http://www.tropicaltidbits.com/analysis/models/ecmwf/2017051912/ecmwf_z500_mslp_namer_9.png

**REPORTED CONDITIONS AND ANOMALIES ARE NOT MEANT TO IMPLY ANYTHING ON A REGIONAL LEVEL UNLESS SPECIFICALLY STATED**

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Looks like we have a May 22-23, 2001 redux coming up. Same timing and possibly similar temperatures? That one was a biggie:

 

99 in downtown Portland

99 in Longview

98 in St. Helens

98 in Beaverton

96 at Portland NWSFO

96 in Vancouver

95 at PDX

93 at Grays River Hatchery

91 at OLM

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Looks like we have a May 22-23, 2001 redux coming up. Same timing and possibly similar temperatures? That one was a biggie:

 

99 in downtown Portland

99 in Longview

98 in St. Helens

98 in Beaverton

96 at Portland NWSFO

96 in Vancouver

95 at PDX

93 at Grays River Hatchery

91 at OLM

 

Definitely feels like a repeat. Models also showing a crack at a second shot of heat to end the month, just like in 2001.

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Definitely feels like a repeat. Models also showing a crack at a second shot of heat to end the month, just like in 2001.

 

That was a pretty impressive heat spike on 5/31/01, on its own merits. Just happened to get overshadowed by 5/22. 

 

That was a weird stretch from 2001-08. Of the 8 occurrences of 93+ heat in May @ PDX, five came during that stretch. 

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Salem's June 32 may be questionable as it occurred in 1899.  Eugene scored a 32 on 6/13/76, which may be more believable.

 

A cool, dry airmass, calm winds, radiational cooling, and strong decoupling in a cold air basin can produce impressive nighttime lows in any season.  See the Peter Sinks, UT thread in this forum for more impressive cold-night stats.

 

That looks like a legitimate reading to me. Oregon was under a very cool airmass around the 5th-6th, when the 32 degree reading at Salem occurred. Lows were 33 degrees at Miramonte Farm in Clackamas County (which had an official COOP station at the time), and 34 degrees at Newberg on the same date that Salem fell to 32 (the 6th). Even downtown Portland hit 39 degrees that morning. East of the Cascades, Silver Lake fell to 17.

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Going to be a huge swing in the modeling once the MJO leaves the IO, where it will bifurcate from the ISM anomaly, and subsequently be initialized/recognized properly.

 

Right now, some of the modeling is struggling to differentiate between the two waves, with the GFS/GEFS conflating them within the IO, while the ECMWF/EPS treating them both as a single MJO wave, propagating it out into the Pacific. Both solutions are likely incorrect (the same thing happened last year on two separate occasions).

 

In the end, the MJO will exit the EHEM, wiilr the strong ISM signature will remain within the IO domain. The MJO component will then degrade into a CCKW as leaves the IPWP, and will accelerate eastward while shallowing, eventually reinforcing the EHEM forcing during the early portion of June, while subsidence returns to the Pacific/dateline.

 

At that point, the wave-1 EHEM convective signature will then be able to resume the poleward diabatic heat/mass dump across the NW Pacific.

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That was a pretty impressive heat spike on 5/31/01, on its own merits. Just happened to get overshadowed by 5/22. 

 

That was a weird stretch from 2001-08. Of the 8 occurrences of 93+ heat in May @ PDX, five came during that stretch. 

 

Yeah, made it a regular thing for awhile. And now that it's been nine years since our last >91 temp, it feels pretty due again.

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Going to be a huge swing in the modeling once the MJO leaves the IO, where it will bifurcate from the ISM anomaly, and subsequently be initialized/recognized properly.

 

Right now, some of the modeling is struggling to differentiate between the two waves, with the GFS/GEFS conflating them within the IO, while the ECMWF/EPS treating them both as a single MJO wave, propagating it out into the Pacific. Both solutions are likely incorrect (the same thing happened last year on two separate occasions).

 

In the end, the MJO will exit the EHEM, wiilr the strong ISM signature will remain within the IO domain. The MJO component will then degrade into a CCKW as leaves the IPWP, and will accelerate eastward while shallowing, eventually reinforcing the EHEM forcing during the early portion of June, while subsidence returns to the Pacific/dateline.

 

At that point, the wave-1 EHEM convective signature will then be able to resume the poleward diabatic heat/mass dump across the NW Pacific.

 

It seems like the models have been struggling with where we go after the ridge builds in. I can't decipher enough of this to get any clues as to what you might be thinking, though.

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Here is a preview of Eugene Register Guard report of June 13th 1976https://news.google.com/newspapers?nid=4pF9x-cDGsoC&dat=19760614&printsec=frontpage&hl=enWeather blows hot,cold and filled with pollen. Nothings Perfect but the weather may be for the next week to  10 days.  The Weather Bureau is predicting clear weather with temperatures to exceed 80 degrees for the next week or more, Ironic after temps plunged to a record cold of 32 degrees early Sunday morning and set another record this morning with a low of 35.

 

 

May of 1976 ran a couple degrees colder at night. http://w2.weather.gov/climate/xmacis.php?wfo=pqrEugene OR May 1976.  Unfortunately you can't link tto the actual data and have to go from there to Eugene Area.  NWS Now Data.

 

Late month is when the pattern change occurred after a nice mid month with a few warm days in there.  Here is a Eugene Register Guard report.https://news.google.com/newspapers?nid=4pF9x-cDGsoC&dat=19760527&printsec=frontpage&hl=en Page 8 Section B Area News:  May 27th 1976  I tried to make it link to page 8 but I think it will automatically go to the front page. Not sure how to work around that.  Dam.  :( 

 

Three Day Weekend Will Be Rainy and Cold. Here's a preview of the article

 

In fact, If the National Weather Service forecast holds up there probably won't be anywhere in the state you can go to escape cloudy skies, showers or rain and chilly nights even down into the 40s.  The unwelcome forecast comes on top of a day Wednesday when sunny skies prevailed throughout the state and the mercury in Eugene climbed to 86F. That weather began deteriorating when at dawn today when a Pacific weather front hit the state bringing rain and cool weather.  The snow level dropped to 4,000 feet.

 

Here is May 28th surface weather map when the pattern change really took place.   https://news.google.com/newspapers?nid=4pF9x-cDGsoC&dat=19760528&printsec=frontpage&hl=en 

 

Forecast Partly Cloudy and Cold Nights  

 

Oregon Cascades Freezing Levels 3,000 feet.

 

May 29th https://news.google.com/newspapers?nid=4pF9x-cDGsoC&dat=19760529&printsec=frontpage&hl=en

 

It could rain today.

Freezing levels rise to 5,000 

 

All the way thru31st the snow levels were below 5,000 feet especially to the north.

 

Average high of 68 Normal 67F.

 

Average low of 40F  Normal low 43F.

 

June average high of 73F with a normal high of 73  

 

June Average low of 43F with a normal low of 47F.  -4 departure.

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It seems like the models have been struggling with where we go after the ridge builds in. I can't decipher enough of this to get any clues as to what you might be thinking, though.

Basically, there are two tropical convective waves present. One of them is stationary, the other is propagating eastward.

 

Currently, they happen to be overlapping one another in the Indian Ocean, hence the modeling is struggling to decipher their interaction(s) and their influence on the extratropical wavetrain.

 

Eventually, the propagatory wave (MJO) will emerge and orbit into the WPAC, at which point the modeling will have a better grasp on the situation, to put it simply. At least that's my take.

 

Until then, expect all kinds of model chaos in the long range.

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First marine push of the season tonight.

 

Felt heavenly on my evening constitutional. 

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Snowfall                                  Precip

2022-23: 95.0"                      2022-23: 17.39"

2021-22: 52.6"                    2021-22: 91.46" 

2020-21: 12.0"                    2020-21: 71.59"

2019-20: 23.5"                   2019-20: 58.54"

2018-19: 63.5"                   2018-19: 66.33"

2017-18: 30.3"                   2017-18: 59.83"

2016-17: 49.2"                   2016-17: 97.58"

2015-16: 11.75"                 2015-16: 68.67"

2014-15: 3.5"
2013-14: 11.75"                  2013-14: 62.30
2012-13: 16.75"                 2012-13: 78.45  

2011-12: 98.5"                   2011-12: 92.67"

It's always sunny at Winters Hill! 
Fighting the good fight against weather evil.

 

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Euro is much more robust with the crash again as well.

 

The ECMWF ensemble mean had not been showing any real crash... 00Z EPS just coming out shows a big crash and fast.   Already here on Tuesday evening.

 

So it finally caved to the operational run.   I guess I was onto something when I said the EPS mean is only right when its troughier than the operational.   :lol:  

**REPORTED CONDITIONS AND ANOMALIES ARE NOT MEANT TO IMPLY ANYTHING ON A REGIONAL LEVEL UNLESS SPECIFICALLY STATED**

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The ECMWF ensemble mean had not been showing any real crash... 00Z EPS just coming out shows a big crash and fast. Already here on Tuesday evening.

 

So it finally caved to the operational run. I guess I was onto something when I said the EPS mean is only right when its troughier than the operational. :lol:

Yeah, you might have been. It's actually amazing to see that shortwave squeeze through those two anticyclones..that thing shouldn't be there. :lol:

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For those who are interested in the difference between warm PNW summers and cool PNW summers in the tropics, here's a reference, and a site to track it going forward.

 

Cool summers (in context of 2017's boundaries): 1954, 1980, 1983, 1993, 1995, 2011, 2012.

 

Note the strong EHEM convection and dateline subsidence:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/A6020691-619E-4B0E-BA74-CFB15354B2F5_zpsj5qekcvk.png

 

Warm summers (also in context, though tougher to match adequately): 1958, 1967, 1972, 1982, 1997, 2004, 2005, 2014, 2015).

 

Note the string Pacific convection, and EHEM subsidence:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/B0FC998D-B7A8-4693-AC03-14BD987A809A_zpspmtjkczc.png

 

Modeling over the next few weeks, linked below. We're definitely following the cooler summer analogs with the EHEM convection and Pacific subsidence. Shifted a bit west of the mean given the MJO propagating across the Pacific under the background state:

 

http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=global&pkg=chi200&runtime=2017052000&fh=156&xpos=0&ypos=0

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Here is the 00Z EPS mean at day 10 (Memorial Day).

 

This will end up troughy somehow.

 

eps_z500_noram_41.png

I think that, overall, you'll enjoy the period from now until early June. Unless a few more rogue shortwaves can wiggle their way in, like the one next week.

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Plus if you're visiting DC in June, you definitely won't have to worry about cool, drizzly weather. So I think you're pretty much golden, regardless of how the pattern unfolds. :rolleyes:

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I think that, overall, you'll enjoy the period from now until early June. Unless a few more rogue shortwaves can wiggle their way in, like the one next week.

 

Well... that shortwave results in 4 days of showers and chilly weather.    And then early June is just a couple days away after that... and then raging jet stream and lots of rain again?   Novemberish?   

**REPORTED CONDITIONS AND ANOMALIES ARE NOT MEANT TO IMPLY ANYTHING ON A REGIONAL LEVEL UNLESS SPECIFICALLY STATED**

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Well... that shortwave results in 4 days of showers and chilly weather. And then early June is just a couple days away after that... and then raging jet stream and lots of rain again? Novemberish?

To be honest, I'm not sure if it'll be a retrogression or jet extension that breaks down the ridge. If there's a bunch of Indonesian convection, as is modeled by the ECMWF/EPS, then it might be a retrogression with less westerly flow, at least initially. The GEPS/GEFS solutions, on the other hand, would prolong the ridging a bit, but would follow with a jet extension.

 

So, too early to know. Or, at least too early for me to know.

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To be honest, I'm not sure if it'll be a retrogression or jet extension that breaks down the ridge. If there's a bunch of Indonesian convection, as is modeled by the ECMWF/EPS, then it might be a retrogression with less westerly flow, at least initially. The GEPS/GEFS solutions, on the other hand, would prolong the ridging a bit, but would follow with a jet extension. So, too early to know.

 

But either way... its time to put away the summer stuff? Its been a good run. We had 4 days last week without rain and 4 nice days coming up now. Summer has worn out its welcome. Focusing on Thanksgiving now. ;)

**REPORTED CONDITIONS AND ANOMALIES ARE NOT MEANT TO IMPLY ANYTHING ON A REGIONAL LEVEL UNLESS SPECIFICALLY STATED**

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But either way... its time to put away the summer stuff? Its been a good run. We had 4 days last week without rain and 4 nice days coming up now. Summer has worn out its welcome. Focusing on Thanksgiving now.

A big, fat ridge is about to park over you for several days. Maybe you should try and enjoy that first, then worry about what happens afterwards...afterwards. ;)

 

We have a spare bedroom if you're craving a blowtorch.

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A big, fat ridge is about to park over you for several days. Maybe you should try and enjoy that first, then worry about what happens afterwards...afterwards. ;)

 

We have a spare bedroom if you're craving a blowtorch.

Might take you up on that... it sort of sucks being warned that we better enjoy 4 nice days because as we go into summer its going to get much worse after the crazy wet spring we have had. I say this knowing that you are almost guaranteed to be right. :)

**REPORTED CONDITIONS AND ANOMALIES ARE NOT MEANT TO IMPLY ANYTHING ON A REGIONAL LEVEL UNLESS SPECIFICALLY STATED**

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Also... more kudos to Phil for predicting model chaos and then an hour later the ECMWF comes out completely different than the 12Z run.    

 

You are very skilled at reading the tea leaves when it comes to global weather patterns.  

**REPORTED CONDITIONS AND ANOMALIES ARE NOT MEANT TO IMPLY ANYTHING ON A REGIONAL LEVEL UNLESS SPECIFICALLY STATED**

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Might take you up on that... it sort of sucks being warned that we better enjoy 4 nice days because as we go into summer its going to get much worse after the crazy wet spring we have had. I say this knowing that you are almost guaranteed to be right. :)

Also... more kudos to Phil for predicting model chaos and then an hour later the ECMWF comes out completely different than the 12Z run.

 

You are very skilled at reading the tea leaves when it comes to global weather patterns.

 

Thanks for the kind words. Sometimes Mother Nature goes easy on me. I'm not sure the swings are done yet, though.

 

Are you guys still doing that science event in June? If so, it'll probably be warm enough for you. :lol:

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Thanks for the kind words. I'm not sure the swings are done yet, either.

 

Are you guys still doing that science event in June? If so, it'll probably be warm enough for you. :lol:

 

That is the plan... still trying to coordinate work schedules.    

**REPORTED CONDITIONS AND ANOMALIES ARE NOT MEANT TO IMPLY ANYTHING ON A REGIONAL LEVEL UNLESS SPECIFICALLY STATED**

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That is plan... still trying to coordinate work schedules.

Awesome. Best of luck.

 

If I'm not in Denmark, perhaps Fred and I could meet you guys somewhere. Depends on whether my sister and aunt drag me out there, though.

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The parallel CMC ensembles have an outrageous warm bias in the extended range. I can't even get a coherent picture at 500mb..nothing but a sea of red. :lol:

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