May 2017 Observations and Model Discussion for the Pacific Northwest

[stuffradio]

The latest model shows a real strong warm ridge showing up. I'm so excited!

[Timmy Supercell]

I think it's been a while since I did a temperature update for my area.

 

March had a Mean of +3.4. April was only a tiny bit below average with a Mean of -0.9.

 

Dec/Jan/Feb period was -1.9 here. Although January was a cold anomaly at -6.2. Interesting season. I really wonder how Spring will end up this time.

 

Oct-Apr period, extremely windy. This easily ranks far above any other water year for wind, and we're not done with the water year (still have YET to factor in my summer storm induced winds!!).

 

I was close to a few t'storms (saw flashes on 03/17 and there were weak convective echoes about 12 days ago near K-Falls).

 

Overall very diverse weather here I have been experiencing.

[SilverFallsAndrew]

Low of 32 this morning

[Phil]

http://i724.photobucket.com/albums/ww243/phillywillie/Mobile%20Uploads/136FAA49-541E-4F59-8E9C-615037B20A90_zpsdbwprgz3.png

[TT-SEA]

What defines an extremely negative NAO?

[Phil]

What defines an extremely negative NAO? Is it the ridge off the East Coast?

 

http://www.tropicaltidbits.com/analysis/models/gfs/2017050106/gfs_z500_mslp_namer_2.png

No, that's the Bermuda High. The NAO is defined by the NATL pressure differential by latitude. Look for higher than average 500mb heights near/over Greenland during a -NAO:

 

http://www.cpc.ncep.noaa.gov/data/teledoc/nao.shtml

[TT-SEA]

No, that's the Bermuda High. The NAO is defined by the NATL pressure differential by latitude. Look for higher than average 500mb heights near/over Greenland during a -NAO:

 

http://www.cpc.ncep.noaa.gov/data/teledoc/nao.shtml

Yeah... I did some research after my post and saw my assumption was wrong.

[stuffradio]

I ended up with 9.81 inches last month.

[wx_statman]

It was 49/32 on this day in 1964, at PDX. 

 

Absolutely tanked PDO (-2.31) and PNA (-2.68) that May, tanked Modoki zone B (-1.46, only lower value since was July 1970) following a transition from a Nino, and volcanic influences from the Agung eruption. Ridiculously cold spring and overall year for PDX. Interesting times. 

[SilverFallsAndrew]

It was 49/32 on this day in 1964, at PDX.

 

Absolutely tanked PDO (-2.31) and PNA (-2.68) that May, tanked Modoki zone B (-1.46, only lower value since was July 1970) following a transition from a Nino, and volcanic influences from the Agung eruption. Ridiculously cold spring and overall year for PDX. Interesting times.

Pretty incredible.

 

I had a low of 25 on this date in 2013 I believe. Easily my coldest low in May since I moved here.

[Jesse]

It was 49/32 on this day in 1964, at PDX. 

 

Absolutely tanked PDO (-2.31) and PNA (-2.68) that May, tanked Modoki zone B (-1.46, only lower value since was July 1970) following a transition from a Nino, and volcanic influences from the Agung eruption. Ridiculously cold spring and overall year for PDX. Interesting times. 

 

Great info. 1964 never gets talked about too much on here (aside from the December cold wave/flooding) but it was pretty impressive. PDX's coldest year on record, beating the next coldest (1955) by 0.4F, with an annual average of 50.1F. Normal for PDX is 54.5F.

 

Spring through early winter 1964 had a very impressive run @ PDX.  Fourth coldest March on record, second coldest April on record, coldest May on record, third coldest June on record, fifth coldest July on record, second coldest August on record, coldest September (!!) on record, fourth coldest November on record and then the massive cold wave in mid-December to top things off.

[Jesse]

The Euro has been gradually coming around to the GFS, not cutting off energy as quickly late in the week, which leads to a bigger crash/cooldown for us Friday-Saturday. The 12Z looks the most impressive yet.

 

Warms up quickly again after that though. Some seasonably warm days. Although there have been hints of another big cooldown late in the ten day period as the cutoff low over California re-absorbs into a full latitude trough.

[Tenochtitlan]

Great info. 1964 never gets talked about too much on here (aside from the December cold wave/flooding) but it was pretty impressive. PDX's coldest year on record, beating the next coldest (1955) by 0.4F, with an annual average of 50.1F. Normal for PDX is 54.5F.

 

Spring through early winter 1964 had a very impressive run @ PDX.  Fourth coldest March on record, second coldest April on record, coldest May on record, third coldest June on record, fifth coldest July on record, second coldest August on record, coldest September (!!) on record, fourth coldest November on record and then the massive cold wave in mid-December to top things off.

I looked up that year for Bellingham on Wunderground. It was maybe not as impressive here, but there was a day in December when it was 4.5 degrees at 10 AM! Sadly that day's full data is missing on Wunderground.

[wx_statman]

Pretty incredible.

 

I had a low of 25 on this date in 2013 I believe. Easily my coldest low in May since I moved here.

 

Yep, 2013. We caught the edge of that historic airmass sliding down the country's midsection. Snow down to Arkansas in May...

[wx_statman]

Great info. 1964 never gets talked about too much on here (aside from the December cold wave/flooding) but it was pretty impressive. PDX's coldest year on record, beating the next coldest (1955) by 0.4F, with an annual average of 50.1F. Normal for PDX is 54.5F.

 

Spring through early winter 1964 had a very impressive run @ PDX.  Fourth coldest March on record, second coldest April on record, coldest May on record, third coldest June on record, fifth coldest July on record, second coldest August on record, coldest September (!!) on record, fourth coldest November on record and then the massive cold wave in mid-December to top things off.

 

We have the Beatles to thank for that.

[Jesse]

We have the Beatles to thank for that.

 

I was actually thinking about the same thing. Would have been fun times to be around.

 

They came to the U.S. and were on Sullivan in February 1964, then the next month an unprecedented string of top cold months began!

[ShawniganLake]

I looked up that year for Bellingham on Wunderground. It was maybe not as impressive here, but there was a day in December when it was 4.5 degrees at 10 AM! Sadly that day's full data is missing on Wunderground.

Abbotsford hit -1F with winds sustained around 30mph. Agassiz dropped to -5F. Top tier stuff. Probably up there with anything outside of Jan 1950.

[BLI snowman]

It was 49/32 on this day in 1964, at PDX. 

 

Absolutely tanked PDO (-2.31) and PNA (-2.68) that May, tanked Modoki zone B (-1.46, only lower value since was July 1970) following a transition from a Nino, and volcanic influences from the Agung eruption. Ridiculously cold spring and overall year for PDX. Interesting times. 

 

And a year later we had the only May snowfall that I'm aware of for the lower elevations of the Portland area on 5/5/1965, with some light non-sticking snow showers early that morning. 

[SilverFallsAndrew]

Yep, 2013. We caught the edge of that historic airmass sliding down the country's midsection. Snow down to Arkansas in May...

 

May 2013 was interesting. We ended up with a warm/dry first half of the month and then a wet 2nd half of the month. 

 

The morning of May 22, 2013 I woke up to wet snow falling with temps in the mid-30s. Had a high of only 43 at my house that day, Silver Falls recorded a high of 41 which tied their all time min max for May. 

 

Overall though I believe that month ended up slightly above average. 

[ShawniganLake]

Drizzly here today.

 

No sunny space needle cam shots today.

[Jesse]

Drizzly here today.

 

No sunny space needle cam shots today.

Some really warm days are right around the corner now. Fret not.

[SilverFallsAndrew]

And a year later we had the only May snowfall that I'm aware of for the lower elevations of the Portland area on 5/5/1965, with some light non-sticking snow showers early that morning.  

 

 

46/31 at Silver Falls that day with 0.46" of precip and a T of snow observed. 

[SilverFallsAndrew]

Ended April with a -0.1 departure. Highs were below normal, lows were above normal.

 

The 8.80" of rain I got was 2.6" above average. 

 

Departures so far this year:

 

January: -4.7

February: -1.2

March:    +0.3

April:       -0.1

 

February-April's lows were about +2, but highs were well below normal all 3 months.

[BLI snowman]

I was actually thinking about the same thing. Would have been fun times to be around.

 

They came to the U.S. and were on Sullivan in February 1964, then the next month an unprecedented string of top cold months began!

 

Winter of '63-64 was pretty garbage, though. Kind of just bled right into the spring and gave us 6-7ish months of the same weather.

[SilverFallsAndrew]

January 64' looks like it was pretty wet....

 

 

December 1964 wow... 24.30" of precip with the last four days of the month missing...Given the snow depth went from 0-10" during that time frame the true precip amount was probably in the 25-26" range...
 

https://climate.usurf.usu.edu/reports/e15daily.php?stn=USC00357809&year=1964&month=12&unit=EN&network=direct:ghcn&sidebar=0

[Jesse]

Ended April with a -0.1 departure. Highs were below normal, lows were above normal.

 

The 8.80" of rain I got was 2.6" above average.

 

Departures so far this year:

 

January: -4.7

February: -1.2

March: +0.3

April: -0.1

 

February-April's lows were about +2, but highs were well below normal all 3 months.

Lows were below normal in February and April up here. Slightly above normal in March though.

 

It's possible your area is experiencing some UHI from the chicken coop.

[SilverFallsAndrew]

Lows were below normal in February and April up here. Slightly above normal in March though.

 

It's possible your area is experiencing some UHI from the chicken coop.

Probably more like the below average number of clear nights.

[Front Ranger]

It was 49/32 on this day in 1964, at PDX. 

 

Absolutely tanked PDO (-2.31) and PNA (-2.68) that May, tanked Modoki zone B (-1.46, only lower value since was July 1970) following a transition from a Nino, and volcanic influences from the Agung eruption. Ridiculously cold spring and overall year for PDX. Interesting times. 

 

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.

[Front Ranger]

The Euro has been gradually coming around to the GFS, not cutting off energy as quickly late in the week, which leads to a bigger crash/cooldown for us Friday-Saturday. The 12Z looks the most impressive yet.

 

Warms up quickly again after that though. Some seasonably warm days. Although there have been hints of another big cooldown late in the ten day period as the cutoff low over California re-absorbs into a full latitude trough.

 

The setup on the 12z Euro is probably the best yet for a possible t-storm outbreak.

[Jesse]

Probably more like the below average number of clear nights.

I suppose it's possible that there were more nights with clouds banked up against the Cascades thanks to a lot of moist westerly flow. We actually had quite a few mostly clear nights in the 30s up here last month.

[Front Ranger]

Drizzly here today.

 

No sunny space needle cam shots today.

 

[TT-SEA]

Screenshot_2.png

 

That was not today at 1:50 p.m.   

 

Sort of looks like a hot day with a little smog in the distance.  

[Jesse]

Sitting at 52/39 for today so far with low clouds and periods of light rain. The day after tomorrow is going to be a major shock to the system.

[stuffradio]

The 18Z says I will reach almost average rainfall by the 17th

 

.26 inches of rain today.

[Jbolin]

Marginal severe setup to say the least

[ShawniganLake]

The 18Z says I will reach almost average rainfall by the 17th

 

.26 inches of rain today.

The ensemble is very much on the drier side.

[wx_statman]

I was actually thinking about the same thing. Would have been fun times to be around.

 

They came to the U.S. and were on Sullivan in February 1964, then the next month an unprecedented string of top cold months began!

 

Little did those newly-minted Beatles fans know, but we'd never see sustained cold anomalies like that again. 

 

In all seriousness though, 1964 was a special year. The SAM (Southern Annular Mode) was also off the charts negative, so the southern hemisphere was out of wack as well. I'd have to imagine Agung played a role in this as well:

 

http://i349.photobucket.com/albums/q363/dmitrik1/1964_SAM_zps0z0vfamk.jpg

 

The SAM is directly correlated to poleward displacement of westerlies in the southern hemisphere, i.e. the more positive, the more poleward are the westerlies. In 1964 they were suppressed equatorward to a much greater degree than any other year since at least 1957.

[wx_statman]

Abbotsford hit -1F with winds sustained around 30mph. Agassiz dropped to -5F. Top tier stuff. Probably up there with anything outside of Jan 1950.

 

Pretty incredible CAA at PDX as well. Hit 6F in the evening hours of 12/16 with easterly winds of 20-25 mph. 

[wx_statman]

And a year later we had the only May snowfall that I'm aware of for the lower elevations of the Portland area on 5/5/1965, with some light non-sticking snow showers early that morning. 

 

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. 

[wx_statman]

May 2013 was interesting. We ended up with a warm/dry first half of the month and then a wet 2nd half of the month. 

 

The morning of May 22, 2013 I woke up to wet snow falling with temps in the mid-30s. Had a high of only 43 at my house that day, Silver Falls recorded a high of 41 which tied their all time min max for May. 

 

Overall though I believe that month ended up slightly above average. 

 

I liked that May, lots of variety. That was a ridiculous cold trough on 5/22. Latest 50 degree max at PDX as well.