May 2017 Observations and Model Discussion for the Pacific Northwest

[Jesse]

Wow. You get so excited to hear me complain. I am feeling great today... looks like maybe 2 awesome weekends ahead.

 

I think most people in the PNW are feeling particularly optimistic looking at the forecast on their phones.

 

You are completely off base and combatively trying to find something. I said 'oh no' and that maybe it was not 'epic' for rain/snow mix at Bend in May. Off the rails!

My point stands.

[TT-SEA]

My point stands.

 

 

What point?   

 

I am feeling great today.    Its like you wake up to cold and rain and think this is going to be a fun day because Tim will be complaining and miserable.   Then you search for anything to stoke the fire.    I did not say anything combative at all today.   And I am not even concerned with the weather today. 

 

Trump is in trouble and there is beautiful weather ahead.   How does it get any better?   

[Jesse]

Trump is in trouble and there is beautiful weather ahead. How does it get any better?

This I can get in on!

[Phil]

Will 2017 continue the trend of cooler summers across the high Arctic domain? Since 1958, the coolest summers at/above 80N are 2013, 2010, and 2014.

 

http://ocean.dmi.dk/arctic/meant80n.uk.php

 

Interesting how winter temperatures have warmed substantially since the 1970s, yet summer temperatures have actually cooled despite the albedo effect being strongest at this time.

 

[Phil]

Then again, reduced polar temperature seasonality makes sense if the Hadley Cells are indeed slowing, as is being observed. It would explain why the high Arctic seems to cool relative to average upon the initiation of the Asian monsoons, since that's a major heat/moisture source for the Arctic during the summer, along with the NATL.

[Front Ranger]

Combative Jesse today! I have know idea about climo for Bend. I know Denver can see snow in May.

 

Bend sees accumulating snowfall in May about once every 10 years on average.

 

For Denver it's about once every 3 years, although lately it's been every year.

[DareDuck]

I would imagine it's not very frequent though. In my location up higher I probably average like 1 day in May where I see flakes falling, and been since 2012 since I had sticking snow in May.

It's pretty uncommon particularly for the middle of the day and I thought it was pretty cool. By no means "epic" though. Maybe if we get some sticking snow tonight.

[TT-SEA]

Bend sees accumulating snowfall in May about once every 10 years on average.

 

For Denver it's about once every 3 years, although lately it's been every year.

Good to know. I wonder how often Bend sees 39 with a rain/snow mix in May? Probably more often than accumulating snow.

[Phil]

The 18z GFS has caved to the ECMWF ensemble mean, now showing Jesse's retrogression to open the month of June.

[Jesse]

The 18z GFS has caved to the ECMWF ensemble mean, now showing Jesse's retrogression to open the month of June.

I caught that baby way out there.

[DareDuck]

Good to know. I wonder how often Bend sees 39 with a rain/snow mix in May? Probably more often than accumulating snow.

Yea not too uncommon. Just a little more unusual that occurred near peak heating in mid May.

[Phil]

I caught that baby way out there.

Maybe it will actually go down that way. Most of the exact pattern analogs went into a -EPO or -AO first, then undercut the ridge and redeveloped the trough afterwards.

 

Only two analogs had an immediate retrogression following ISM genesis and coinciding MJO/-NAO: 1980 and 1993. Those years keep popping up on the stormvista analog list, so who knows maybe they're the right ones.

 

FWIW, those were also the two strongest May -NAO years on record, which 2017 will likely beat.

[WeatherArchive]

I caught that baby way out there.

What does retrogression do for the PNW?  

[Phil]

What does retrogression do for the PNW?

Ridge "retrogrades" offshore due to upstream forcing, which often helps to re-establish a trough in the western US.

[Jesse]

What does retrogression do for the PNW?

Retrogression of a ridge can often give us a shot of air with some continental influence.

[Timmy Supercell]

Yea not too uncommon. Just a little more unusual that occurred near peak heating in mid May.

 

I just checked out wunderground history for Bend and the last time they saw wet snow in May was 05/09/2011. Seems a lot more uncommon there in May than in Klamath Falls, and here it's pretty uncommon as is.

[Jesse]

PDX saw NW winds gusting up around 40mph today. That isn't too common.

 

This storm is a dynamic little sucker. Wouldn't surprise me to see it give significant snow to parts of the central Rockies as it digs SE.

[Trainwreck]

I just checked out wunderground history for Bend and the last time they saw wet snow in May was 05/09/2011. Seems a lot more uncommon there in May than in Klamath Falls, and here it's pretty uncommon as is.

I was driving just south of Madras today and was caught up in that dust storm that caused a multi car pileup on 97. What a windy day, I recorded a gust of 48 but nit wasn't the high speeds, it was the frequency. Just constant all day and still is.

 

To add to the conversation up above, it's usually graupel that is so common this late I the year. I've lived in Redmond for about 8 years and have seen graupel quite frequently late in the spring here, June as well.

[DareDuck]

I was driving just south of Madras today and was caught up in that dust storm that caused a multi car pileup on 97. What a windy day, I recorded a gust of 48 but nit wasn't the high speeds, it was the frequency. Just constant all day and still is.

 

To add to the conversation up above, it's usually graupel that is so common this late I the year. I've lived in Redmond for about 8 years and have seen graupel quite frequently late in the spring here, June as well.

Wow, I heard it was quite a doozy. Winds were definitely pretty crazy today. Gusts between 40-45mph from dawn until this afternoon. I definitely didn't think my comment about the snow earlier would spark the conversation it did.

[Front Ranger]

After a warm first 10 days, then a very cool last 6 days, most places are running a little below normal temps for the month. However, with the extended warm spell coming up, it looks very likely that May 2017 will continue the streak of regionally warm Mays in the PNW dating back to 2013 (2012 was the last cool May).

 

FWIW, here is the composite for the summers following Mays of 55.0+ averages at OLM (at least 1.5 degrees warmer than normal).

 

[Phil]

After a warm first 10 days, then a very cool last 6 days, most places are running a little below normal temps for the month. However, with the extended warm spell coming up, it looks very likely that May 2017 will continue the streak of regionally warm Mays in the PNW dating back to 2013 (2012 was the last cool May).

 

FWIW, here is the composite for the summers following Mays of 55.0+ averages at OLM (at least 1.5 degrees warmer than normal).

 

cd67.6.172.175.135.21.7.18.prcp.png

Looks worthless in the predictability department. I see 2014, 2015, 1983, and 1993 on that list. Talk about a mixed bag of infinite proportions.

[Phil]

Though I guess if you isolate the -NAO years which were followed by weak ENSO summers, predictability increases with the four years that meet this criteria (1983, 1993, 1995, 2016).

 

Those are still very different in a number of ways, though, albeit some large scale homogeneity is present in this assortment.

[TT-SEA]

After a warm first 10 days, then a very cool last 6 days, most places are running a little below normal temps for the month. However, with the extended warm spell coming up, it looks very likely that May 2017 will continue the streak of regionally warm Mays in the PNW dating back to 2013 (2012 was the last cool May).

 

FWIW, here is the composite for the summers following Mays of 55.0+ averages at OLM (at least 1.5 degrees warmer than normal).

 

cd67.6.172.175.135.21.7.18.prcp.png

 

 

The unusual story this spring is really the rain and not the temperatures.   The record setting persistence of the rain is also indicative of the pattern.  

 

SEA is just .35 away from breaking the record for the Feb-May period set in 2014.      

 

SEA has received 22.52 inches of rain since February 1st.    An incredibly wet 3.5 month period.  

 

1983 and 1993 were not very wet in that period.   1983 had 11.54 inches for the entire Feb-May period... and 1993 had 12.55 inches.

 

The top 5:

 

2014 - 22.88

2017 - 22.52

1972 - 19.66

1961 - 18.99

1996 - 17.85

[wx_statman]

For those wondering, a pretty epic snowfall in central/eastern Oregon occurred in mid-May 1974. Totals included:

 

12" in Paisley on the 17th-18th

10" in Lakeview on the 17th

8" in Silver Lake on the 17th-18th

5.6" in Baker City on the 18th

3.4" in Bend on the 17th-18th

 

This was also a very impressive snowfall at lower elevations, with 4.9" in Marion Forks, OR (2,473') and 0.7" at Cedar Lake, WA (1,561').

 

In the S. WA Cascades, a record breaking late season snowfall occurred on this date in 1971. On May 16th, 18.8" fell at Stampede Pass and 6.6" fell in Longmire (2,700'). Paradise Lodge was buried by 31" on the 16th-17th. 

[wx_statman]

The unusual story this spring is really the rain and not the temperatures.   The record setting persistence of the rain is also indicative of the pattern.  

 

SEA is just .35 away from breaking the record for the Feb-May period set in 2014.      

 

SEA has received 22.52 inches of rain since February 1st.    An incredibly wet 3.5 month period.  

 

1983 and 1993 were not very wet in that period.   1983 had 11.54 inches for the entire Feb-May period... and 1993 had 12.55 inches.

 

The top 5:

 

2014 - 22.88

2017 - 22.52

1972 - 19.66

1961 - 18.99

1996 - 17.85

 

Interestingly, the other four summers on that list were toasty. 

[Jesse]

For those wondering, a pretty epic snowfall in central/eastern Oregon occurred in mid-May 1974. Totals included:

 

12" in Paisley on the 17th-18th

10" in Lakeview on the 17th

8" in Silver Lake on the 17th-18th

5.6" in Baker City on the 18th

3.4" in Bend on the 17th-18th

 

This was also a very impressive snowfall at lower elevations, with 4.9" in Marion Forks, OR (2,473') and 0.7" at Cedar Lake, WA (1,561').

 

In the S. WA Cascades, a record breaking late season snowfall occurred on this date in 1971. On May 16th, 18.8" fell at Stampede Pass and 6.6" fell in Longmire (2,700'). Paradise Lodge was buried by 31" on the 16th-17th. 

 

How does today's event compare? I know Longmire got dumped on this morning.

[Phil]

The unusual story this spring is really the rain and not the temperatures. The record setting persistence of the rain is also indicative of the pattern.

 

SEA is just .35 away from breaking the record for the Feb-May period set in 2014.

 

SEA has received 22.52 inches of rain since February 1st. An incredibly wet 3.5 month period.

 

1983 and 1993 were not very wet in that period. 1983 had 11.54 inches for the entire Feb-May period... and 1993 had 12.55 inches.

 

The top 5:

 

2014 - 22.88

2017 - 22.52

1972 - 19.66

1961 - 18.99

1996 - 17.85

Hmmm, now that's interesting to me, especially considering none of those years are remotely similar to 2017 in the tropical Pacific/IPWP area (which is where I always look first).

 

Can you list the top-15 wettest years for that period? Or maybe provide a link to the data source? Thanks in advance.

[wx_statman]

How does today's event compare? I know Longmire got dumped on this morning.

 

Well, if Longmire got more than 2" then it would be pretty rare for them this late in the year. They did get 2.5" on 6/10/2008, which is their record latest measurable snow. That was a pretty special event. 

[TT-SEA]

Hmmm, now that's interesting to me, especially considering none of those years are remotely similar to 2017 in the tropical Pacific/IPWP area (which is where I always look first).

 

Can you list the top-15 wettest years for that period? Or maybe provide a link to the data source? Thanks in advance.

 

 

Its just the WRCC site.

 

Here is the list of top 15 wettest Feb-May periods at SEA:

 

2014 2017 1972 1961 1996 1950 1948 1991 2011 1945 1997 2012 1971 1957 1989

[Phil]

Its just the WRCC site.

 

Here is the list of top 15 wettest Feb-May periods at SEA:

2014 2017 1972 1961 1996 1950 1948 1991 2011 1945 1997 2012 1971 1957 1989

Thanks. Can you link me to the page where you're getting the data? I can only find a page with five years listed.

[Phil]

Nevermind, I found it. I think.

 

http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?wa7473

 

The layout on this site just sucks.

[TT-SEA]

Thanks. Can you link me to the page where you're getting the data? I can only find a page with five years listed.

 

 

Go here... and then scroll down on the left to monthly precip totals.   I just cut and paste into Excel and then sum and sort.

 

http://www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?wa7473

[Phil]

Looking at the aforementioned precipitation data for SEA, I sorted the years for MAR/APR rainfall, to account for the seasonal NAM wind reversal and associated changes to the waveguide(s). So now the precipitation data is representative through the seasonal transition.

 

I then took note of which years featured 4"+ of rainfall @ SEA in both FEB & MAR. The end result was much more homogenous to changes in the global phase state and internally coherent.

 

The years are 1972, 1991, 1993, 1997, 2011, 2014, and 2017.

 

Interesting to note that all except one of these years (2011) was +ENSO. Two of these years preceded super El Niño's (1997 and 1972), one was a failed super-niño attempt (2014), and the other two were modest +ENSO during the following year (1991 and 1993).

 

As for any predictive usefulness, I don't see much, though one of the years (1993) has been an analog since March.

[Phil]

The 00z GFS is sure taking its sweet time propagating this MJO wave. Takes a full two weeks to get from the IO to the dateline:

 

http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=global&pkg=chi200&runtime=2017051700&fh=24&xpos=0&ypos=0

[Front Ranger]

Looking at the aforementioned precipitation data for SEA, I sorted the years for MAR/APR rainfall, to account for the seasonal NAM wind reversal and associated changes to the waveguide(s). So now the precipitation data is representative through the seasonal transition.

 

I then took note of which years featured 4"+ of rainfall @ SEA in both FEB & MAR. The end result was much more homogenous to changes in the global phase state and internally coherent.

 

The years are 1972, 1991, 1993, 1997, 2011, 2014, and 2017.

 

Interesting to note that all except one of these years (2011) was +ENSO. Two of these years preceded super El Niño's (1997 and 1972), one was a failed super-niño attempt (2014), and the other two were modest +ENSO during the following year (1991 and 1993).

 

As for any predictive usefulness, I don't see much, though one of the years (1993) has been an analog since March.

 

I've liked 1991 and 2014 as analogs for awhile (see summer predictions thread).

[Phil]

I've liked 1991 and 2014 as analogs for awhile (see summer predictions thread).

I've also had 1991 as a summer analog for awhile, but definitely not 2014. The latter is almost completely arse-backwards across the tropical EHEM compared to 2017.

[Phil]

Woah...

 

Okay, so I just realized that all of the years I mentioned (except 1997) featured descending easterlies above the tropopause (+QBO to -QBO) during JJA in the middle QBO sigmas:

 

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/7B3F5341-B02A-408C-8448-4B9394C6E351_zps2l3iulav.jpg

 

So far, 2017 is progressing rapidly into the -QBO, which puts it in the 1990s category for said -QBO transitions.

[Timmy Supercell]

I was driving just south of Madras today and was caught up in that dust storm that caused a multi car pileup on 97. What a windy day, I recorded a gust of 48 but nit wasn't the high speeds, it was the frequency. Just constant all day and still is.

 

To add to the conversation up above, it's usually graupel that is so common this late I the year. I've lived in Redmond for about 8 years and have seen graupel quite frequently late in the spring here, June as well.

 

Yeah graupel is extremely common anywhere on the east slopes until late May (sometimes in June but suddenly becomes much less of a possibility by the first week of June). Wet snow or sticking snow in May/June is much harder to see. I can see as many as 10-15 heavy graupel storms in the late Spring here and be lucky to see a few flakes fall in that same time frame. 

 

I recall when I graduated from high school here in June 2011, on literally my last official day of school it was graupeling in the afternoon, with a high in the mid 40's. Kinda chilly for the time of year, it caught the attention of quite a few students. Since then my latest graupels have been in mid-late May. Good thing that summer in 2011 actually turned out to be not very hot and not below normal either. Considering that was one of the coolest Spring's in this area in a long time. Interesting coincidence too because this was just after I moved here, never experienced real Springs here, then I get one the area's most anomalous seasons.

[SilverFallsAndrew]

Up to 4.77" of rain on the month. Slightly above the monthly average.

 

Looking hot early next week. Could be the warmest weather of the summer

[TT-SEA]

Up to 4.77" of rain on the month. Slightly above the monthly average.

 

Looking hot early next week. Could be the warmest weather of the summer

Could happen.