May 2017 Observations and Model Discussion for the Pacific Northwest

[wx_statman]

OLM hit 26 with that air mass. 

 

Remarkably, that's not the latest they've seen a temp that cold. 5/7/2002 and 5/9/96 also both hit 26. Pretty astounding when you consider there are record lows in mid March in that range.

 

That is pretty remarkable. Not much of a seasonal transition. PDX bears this out too - monthly records of 29 in both April and May.

[James Jones]

That is pretty remarkable. Not much of a seasonal transition. PDX bears this out too - monthly records of 29 in both April and May.

 

Out of all the monthly record high/lows at PDX, April's 29 seems the weakest to me. They got down to 23 on 3/29/54 and 24 on 3/30/54. The strongest record would probably be September's 105.

[VancouverIslandSouth]

Another sunny afternoon here in Victoria, but we managed a nice rainy morning/early afternoon to keep things in check. Looks like another possible shot at rain tomorrow evening through Wednesday and then again Thursday evening~Saturday.

 

Ended April with an average temperature around 50F and a little over 1.5" of rain; hopefully this month does better in the rainfall department.

[wx_statman]

Out of all the monthly record high/lows at PDX, April's 29 seems the weakest to me. They got down to 23 on 3/29/54 and 24 on 3/30/54. The strongest record would probably be September's 105.

 

Yeah, I'm surprised the April record has survived this long. We hit 31 in 2008, 31 in 2009, 31 in 2011, and 30 in 2012. You'd think we could have snuck down to 28 at some point in the pre-UHI era. 

 

I think I would actually pick the 100 from May 1983 as the strongest. Mostly because the readings in that event (like the 103 downtown or the 104 in Oregon City) have never been replicated in May. On the other hand, 105 degree readings were recorded in the I-5 corridor on 9/5/1944, so 1988 is not unique in that regard. 

 

In other words, its statistically less likely that we see another shot at 100 in May, than another shot at 105 in September....

[wx_statman]

Speaking of May 1, 1964 - Sitkum 1E, at 610 feet in the southern OR coast range, got 5.0" on that day. That might be the most impressive late season snowfall anywhere in Oregon. 

[James Jones]

Yeah, I'm surprised the April record has survived this long. We hit 31 in 2008, 31 in 2009, 31 in 2011, and 30 in 2012. You'd think we could have snuck down to 28 at some point in the pre-UHI era. 

 

I think I would actually pick the 100 from May 1983 as the strongest. Mostly because the readings in that event (like the 103 downtown or the 104 in Oregon City) have never been replicated in May. On the other hand, 105 degree readings were recorded in the I-5 corridor on 9/5/1944, so 1988 is not unique in that regard. 

 

In other words, its statistically less likely that we see another shot at 100 in May, than another shot at 105 in September....

 

UHI definitely complicates the "strongest record" thing, at this point breaking the January and February record lows is probably less likely than breaking any of the monthly record highs.

 

And good point about May, though we have gotten sort of close a couple times - downtown hit 99 on 5/22/01 (not sure about Oregon City, they seem to be missing data for that date), and going way back another 99 degree reading on 5/29/1887. 4 degrees is a pretty big difference however.

[wx_statman]

UHI definitely complicates the "strongest record" thing, at this point breaking the January and February record lows is probably less likely than breaking any of the monthly record highs.

 

And good point about May, though we have gotten sort of close a couple times - downtown hit 99 on 5/22/01 (not sure about Oregon City, they seem to be missing data for that date), and going way back another 99 degree reading on 5/29/1887. 4 degrees is a pretty big difference however.

 

The trend definitely favors that line of thinking. Tough to imagine a reading below zero, when we haven't dropped below 10 in almost three decades. 

 

BTW, Oregon City hit 95 on 5/22/2001. It appears under 5/23 due to the 24 hour COOP reporting lag. 

[Timmy Supercell]

Wow. First night in May and crickets chirping a lot, and have my window open. Impeccable timing there.

 

Unfortunately I don't hear any frogs.

[Jesse]

The models seem pretty adamant that we see a 60+ low on Wednesday night. If so it would be our earliest on record by about ten days.

[James Jones]

The models seem pretty adamant that we see a 60+ low on Wednesday night. If so it would be our earliest on record by about ten days.

Does this not count? 

 

https://www.wunderground.com/history/airport/KPDX/1980/12/25/DailyHistory.html

[Jesse]

Does this not count? 

 

https://www.wunderground.com/history/airport/KPDX/1980/12/25/DailyHistory.html

 

Nope, that would be our latest ever.

 

Although it is pretty amazing that we've seen 60 degree lows in late December but never in history from January 1-May 14. Says a lot about how cool the upper level airmasses are on average the first several months of the year.

[wx_statman]

Nope, that would be our latest ever.

 

Although it is pretty amazing that we've seen 60 degree lows in late December but never in history from January 1-May 14. Says a lot about how cool the upper level airmasses are on average the first several months of the year.

 

Exactly. Demonstrates how anomalous 3/11/2007 was, as well.

 

https://www.wunderground.com/history/airport/KPDX/2007/3/11/DailyHistory.html?req_city=Portland&req_state=OR&req_statename=&reqdb.zip=97201&reqdb.magic=1&reqdb.wmo=99999

[BLI snowman]

That's the latest Portland area snowfall I'm aware of as well. I remember Raymond Hatton mentioned sticking snow in the West Hills that morning, in that one book. Skamania Fish Hatchery actually recorded 0.1" at 440 feet.

 

We had an incredible run during that era. 1961, 1965, 1967, 1970, and 1972 all brought snow to the western lowlands post-4/20. 

 

Yeah, here is the Oregonian from the next day

 

http://proxy.multcolib.org:2194/cache/arhb/fullsize/pl_005022017_0310_03171_985.pdf

 

The last -PDO phase in general had remarkable springtime anomalies from March to May. There was also May 1962, which is one of only two Mays in downtown Portland to not reach 70 degrees (the other being 1899). 

[BLI snowman]

Models have definitely been spitting out some intense convective parameters for us on Thursday. The synchronization of the thermal low with the 500mb trough axis offshore could be pretty ideal. You don't see LI's of -7 or -8 very often west of the Cacades.

[wx_statman]

Yeah, the last -PDO phase in general had remarkable springtime anomalies. There was also May 1962, which is one of only two Mays in downtown Portland to not reach 70 degrees (the other being 1899). 

 

Throw in years like 1960, 1963 and 1968, and post-April 1st snowfall was pretty much an annual occurrence for a while there. 

 

Then there was the heat wave in early May 1966, which set numerous earliest-100 benchmarks in the Columbia Basin. Kind of the black sheep from that era, although we got snow earlier that spring as well. 

[wx_statman]

Yeah, here is the Oregonian from the next day

 

http://proxy.multcolib.org:2194/cache/arhb/fullsize/pl_005022017_0310_03171_985.pdf

 

The last -PDO phase in general had remarkable springtime anomalies from March to May. There was also May 1962, which is one of only two Mays in downtown Portland to not reach 70 degrees (the other being 1899). 

 

I don't have login info for that. Can you post an image capture? I kinda want to see it!

[TT-SEA]

Water of the PNW coast continues to warm... and the pattern certainly looks conducive for this to continue.

 

http://www.tropicaltidbits.com/analysis/ocean/cdas-sflux_ssta_global_1.png

[TT-SEA]

Ridiculously persistent rain continues into the 4th month now.    This is data from Snoqualmie/North Bend.    

 

Ironically... the next totally dry day will not be until Monday (5/8).   It will rain this evening and tomorrow morning, then Thursday evening, Friday, Saturday, and Sunday according to the 00Z ECMWF.   

 

[SilverFallsAndrew]

Ridiculously persistent rain continues into the 4th month now.    This is data from Snoqualmie/North Bend.    

 

Ironically... the next totally dry day will not be until Monday (5/8).   It will rain this evening and tomorrow morning, then Thursday evening, Friday, Saturday, and Sunday according to the 00Z ECMWF.   

 

 

What is that stations annual average? I am up to 47.59" since January 1st. 85.63" since October 1st. Average annual precip here is 76". 

[TT-SEA]

What is that stations annual average? I am up to 47.59" since January 1st. 85.63" since October 1st. Average annual precip here is 76". 

 

 

 

Probably around 58-60 inches annually on average there.

 

The lack of dry days since the end of January is truly astounding even for this area and it looks to continue.  

[Jesse]

Water of the PNW coast continues to warm... and the pattern certainly looks conducive for this to continue.

 

 

Could you elaborate on what sort of pattern this is?

 

I'm seeing a big ball of cool out there.

[TT-SEA]

Could you elaborate on what sort of pattern this is?

 

I'm seeing a big ball of cool out there.

Lack of cool NW flow. Looks like SW flow for the foreseeable future for the most part.

[Jesse]

Lack of cool NW flow. Looks like SW flow for the foreseeable future for the most part.

Looks pretty variable going forward. Cutoff lows make for a big question mark.

[TT-SEA]

Looks pretty variable going forward. Cutoff lows make for a big question mark.

 

One cut off low... SW flow resumes almost immediately.  

[Jesse]

One cut off low... SW flow resumes almost immediately.

Whatever helps you sleep at night.

[TT-SEA]

Whatever helps you sleep at night.

 

 

Yeah... more wet SW flow would be awesome!    Very comforting.  

[Jesse]

Yeah... more wet SW flow would be awesome! Very comforting.

Light orange waters are worth it!

[TT-SEA]

Light orange waters are worth it!

 

Not really.

[Jesse]

Not really.

Could mean a warm summer if you aren't a fan of logic.

[TT-SEA]

Could mean a warm summer if you aren't a fan of logic.

Not expecting that.

 

Just want the daily rain to end at this point.

[Jesse]

Not expecting that.

 

Just want the daily rain to end at this point.

The upcoming pattern isn't too bad.

[TT-SEA]

The upcoming pattern isn't too bad.

 

The 00Z ECMWF sucked with the surface details.

 

Rain starting Thursday afternoon and going all the way through Sunday for this area.   

 

Sunday was a gem on that run... we get banked low clouds and drizzle against the Cascades instead of dry, sunny northerly flow.  

 

Seems like we can never actually get to an extended dry pattern.  

[stuffradio]

Wow. First night in May and crickets chirping a lot, and have my window open. Impeccable timing there.

 

Unfortunately I don't hear any frogs.

You know what that means? The crickets ate the frogs!

[Jbolin]

SPC appears to be on board for Thursday for the immediate region, potential large hail threat looms for some.

[SilverFallsAndrew]

Snow wiz will always wishcast signals for a cold winter.

 

TT Sea will wishcast for a warm summer.

[Front Ranger]

SPC appears to be on board for Thursday for the immediate region, potential large hail threat looms for some.

 

Unfortunately, some rain will probably accompany the hail, meaning the day will be completely ruined for Tim.

[BLI snowman]

I don't have login info for that. Can you post an image capture? I kinda want to see it!

 

 

Sorry about that, forgot you had to have an account. I'll have to attach it separately.

 

may 6 1965 oregonian.pdf

[epiceast]

Ridiculously persistent rain continues into the 4th month now.    This is data from Snoqualmie/North Bend.    

 

Ironically... the next totally dry day will not be until Monday (5/8).   It will rain this evening and tomorrow morning, then Thursday evening, Friday, Saturday, and Sunday according to the 00Z ECMWF.   

 

Tim, why are you itching about rain every day when we're about to get some epic thunderstorms?

[TT-SEA]

Tim, why are you itching about rain every day when we're about to get some epic thunderstorms?

I don't care too much about thundestorms... unless we need rain. Its just so wet out there. We need a dry pattern.

[BLI snowman]

The stories about the PTA, Social Security Benefits, the Pretty, Blond Songbird, and others show how much times have changed.

 

Yeah, the Rose Festival princess bit was a funny read.