Salem (SLE) 850 mb temp records

[IbrChris]

Salem 850 mb Temperature Records (in Celsius)

MAX 850 TEMP
Jan: 18.8 on 16/2009 12z
Feb: 16.7 on 6/1954 21z
Mar: 15.9 on 19/1960 12z
Apr: 19.3 on 28/1987 00z
May: 26.6 on 29/1983 00z
Jun: 26.6 on 16/1961 00z
Jul: 27.6 on 13/2002 00z
Aug: 27.3 on 7/1972 00z
Sep: 28.3 on 3/1988 00z
Oct: 24.0 on 3/1980 00z
Nov: 21.8 on 2/1962 00z
Dec: 19.3 on 25/1985 12z

MIN 850 TEMP
Jan: -18.1 on 21/1962 12z
Feb: -17.2 on 15/1956 21z
Mar: -12.6 on 4/1955 09z
Apr: -8.7 on 17/1972 12z
May: -7.1 on 5/1965 12z
Jun: -3.3 on 2/1976 12z
Jul: 0.0 on 2/1955 15z
Aug: -0.3 on 31/1973 12z
Sep: -2.2 on 24/1970 12z
Oct: -6.9 on 28/1971 12z
Nov: -16.0 on 12/1955 15z
Dec: -22.1 on 21/1990 12z

More here:

Max 850 mb temps
http://www.crh.noaa.gov/images/unr/soo/T850/top50-T850.pdf

and

Min 850 mb temps
http://www.crh.noaa.gov/images/unr/soo/T850/low50-T850.pdf

[TT-SEA]

Interesting that the record 850mb temp is higher for January than for February and March.

 

Also seems strange that the record cold 850mb temp for January is only -18C.

[BLI snowman]

Interesting that the record 850mb temp is higher for January than for February and March.

 

Also seems strange that the record cold 850mb temp for January is only -18C.

 

The period is measuring 1951 to present, I believe. Which explains the lack of representation from one January 1950 (and March 1951).

 

It is hard to believe that January 1957 didn't go below -9.2 at SLE. I find that kind of suspect, that was a heavy duty airmass. Not as upper level centric as some, but surely it must have been colder than that.

[IbrChris]

Not to mention that prior to Salem being the location of rawinsonde launches it was at Portland (IAP) from Feb 2, 1953 to May 31, 1956.
 

NOAA Rawinsonde Database

 

Salem/Portland data:

IAP  24211 72698  45.60 122.60    6  460101 460228  PORTLAND                 OR  USIAP  24211 72698  45.60 122.60    7  530202 560531  PORTLAND                 OR  USSLE  24232 72694  44.92 123.02   61  560601 999999  SALEM                    OR  USMedford:MFR  24225 72597  42.37 122.87  401  390901 840813  MEDFORD                  OR  USMFR  24225 72597  42.37 122.87  397  840814 999999  MEDFORD                  OR  US

Here are the western WA records:

NEJ  24208 72793  47.53 122.30    7  440901 450702  SEATTLE/BOEING FLD       WA  USNEJ  24244 72793  47.68 122.27   10  450300 490499  SEATTLE/NAS              WA  USNEJ  24244 72793  47.68 122.27   19  490400 540201  SEATTLE/NAS              WA  USNEJ  24244 72793  47.68 122.27   10  540202 560628  SEATTLE/NAS              WA  USSEA  24233 72793  47.45 122.30  124  560629 560913  SEATTLE/TACOMA APT       WA  USSEA  24233 72793  47.45 122.30  125  560914 620531  SEATTLE/TACOMA APT       WA  USOLM  24227 72792  46.97 122.90   58  620601 640131  OLYMPIA                  WA  USTTI  24240 72798  48.38 124.73   33  430315 541014  TATOOSH ISLAND           WA  USTTI  24240 72798  48.38 124.73   31  541015 660801  TATOOSH ISLAND           WA  USUIL  94240 72797  47.95 124.55   58  660802 661009  QUILLAYUTE               WA  USUIL  94240 72797  47.95 124.55   56  661010 999999  QUILLAYUTE               WA  US

[IbrChris]

Jan 1950 850 mb Temps at Seattle (NEJ-SEA) and Tatoosh Island (TTI)

Lowest value was -20.0c on Jan 14, 1950 at 15z at Seattle. At the same time Tatoosh Island sounding showed -18.9c
 

[IbrChris]

The period is measuring 1951 to present, I believe. Which explains the lack of representation from one January 1950 (and March 1951).

 

It is hard to believe that January 1957 didn't go below -9.2 at SLE. I find that kind of suspect, that was a heavy duty airmass. Not as upper level centric as some, but surely it must have been colder than that.

NWS employs some kind of QC filter to the raw sounding data, comparing the data to both nearby pressure levels and other upper air sites nearby. It's possible that the coldest 850 mb temp in Jan 1957 was flagged and thus doesn't appear among the records, however it's fairly unlikely that is the case. Keep in mind especially at Portland/Salem that very cold low-level airmasses (below 850 mb) do in fact occur with arctic blasts, late Dec 1968 is a case in point.

 

Try querying http://mesonet.agron.iastate.edu/archive/raob/

[SilverFallsAndrew]

I believe Eugene's all time January record of -4 was in January 1957...

[IbrChris]

I believe Eugene's all time January record of -4 was in January 1957...

Yes, not considering the -15 on Jan 10, 1868 shown in the COOP sheets as being the coldest temp recorded there up until the 1890s.

 

However Salem only dropped to 9 the same night so there was probably snowcover at Eugene that allowed it to perform very well, similar to last December.

[IbrChris]

The period is measuring 1951 to present, I believe. Which explains the lack of representation from one January 1950 (and March 1951).

 

It is hard to believe that January 1957 didn't go below -9.2 at SLE. I find that kind of suspect, that was a heavy duty airmass. Not as upper level centric as some, but surely it must have been colder than that.

March 1951 only fell to -11.9c at Tatoosh Island on the 6th at both the 3z and 15z soundings. Also -11.9c at Seattle on Mar 3, 1951 at 22z. By contrast March 1955 was colder at 850 mb, it hit -16.8c at Seattle on 3/4/1955 15z and -14.4c at Tatoosh Island the same time. Being that Salem/Portland data exists for March 1955 (-12.6c at coldest record) we can assume it wasn't likely as cold at 850 mb in the 1951 event throughout the PNW, at least not at 850 mb.

[BLI snowman]

March 1951 only fell to -11.9c at Tatoosh Island on the 6th at both the 3z and 15z soundings. Also -11.9c at Seattle on Mar 3, 1951 at 22z. By contrast March 1955 was colder at 850 mb, it hit -16.8c at Seattle on 3/4/1955 15z and -14.4c at Tatoosh Island the same time. Being that Salem/Portland data exists for March 1955 (-12.6c at coldest record) we can assume it wasn't likely as cold at 850 mb in the 1951 event throughout the PNW, at least not at 850 mb.

 

1951 was probably in the -9 to -10c range further to the south. Probably -15c or so at BLI. Top tier for March, but it was not an arctic event for Oregon as onshore flow never really died.

 

1955 had super cold air but was pretty unfavorable for places outside of the Fraser River outflow trajectory to post cold daytime temps. Highs were in the low 40s in NW OR that day the 850mb temp was -12.6.

[BLI snowman]

1957 was in part an inversion, but the 33/21 at OTH on January 26, 1957 suggests a pretty significant upper level event that day. Colder than -9c.

[IbrChris]

1957 was in part an inversion, but the 33/21 at OTH on January 26, 1957 suggests a pretty significant upper level event that day. Colder than -9c.

Feel free to look up the sounding data: http://mesonet.agron.iastate.edu/archive/raob/

 

Try Medford, that is probably more representative of conditions in that area than Salem.

 

I can show you plenty of examples to illustrate that there's not that decent of a correlation between 850 mb temp and surface high temp, ESPECIALLY in winter when the surface to 850 layer is often not fully mixed. Also 850 mb temps are a rather poor predictor of surface high temp beyond the first day or two of an arctic blast. Dec 1968 was probably one of the most extreme examples, as it was around -10c at the surface in Salem while it was +2c at 850 mb in the wake of a rather nondescript arctic blast for Oregon (much bigger deal in WA).

[IbrChris]

Looks like MFR had a 850 mb temp of -11c on Jan 26, 1957. That cold air was centered further S than typical.

[BLI snowman]

Feel free to look up the sounding data: http://mesonet.agron.iastate.edu/archive/raob/

 

Try Medford, that is probably more representative of conditions in that area than Salem.

 

I can show you plenty of examples to illustrate that there's not that decent of a correlation between 850 mb temp and surface high temp, ESPECIALLY in winter when the surface to 850 layer is often not fully mixed. Also 850 mb temps are a rather poor predictor of surface high temp beyond the first day or two of an arctic blast. Dec 1968 was probably one of the most extreme examples, as it was around -10c at the surface in Salem while it was +2c at 850 mb in the wake of a rather nondescript arctic blast for Oregon (much bigger deal in WA).

 

The 1968 airmass was a very extreme E-W gradient, but it was still pretty significantly cold over NW OR, looks like -12c over Portland.

 

http://vortex.plymouth.edu/gifs/140213021132.gif

[BLI snowman]

The 1968 airmass was a very extreme E-W gradient, but it was still pretty significantly cold over NW OR, looks like -12c over Portland.

 

 

Then -31c over extreme NE WA on the afternoon of December 29, 1968. Easy to see how that one was so extreme, the PV basically positioned itself right over lower AB and the PNW got the outer edges of it. Incredible event.

 

http://vortex.plymouth.edu/gifs/140213021458.gif

[IbrChris]

Unfortunately I've found the coarse reanalysis isn't much better than a rough estimate west of the Cascades. Sounding data for 30th of Dec 1968 at SLE clearly showed a warm tongue aloft atop a very cold boundary layer in the minus teens Celsius. I'll post a sounding tomorrow. There was a massive DP depression though and when overrunning moved in it was all snow, over a foot SLE to PDX. At any rate that event wasn't too impressive at 850 mb down here sorta like this last one. SLE hit -7.3c at 850 and -7.8c at 925 at the coldest. Clearly colder at sfc as PDX fell into upper teens with heavy snow during the afternoon last Thursday (early high of 23). Airmass was slightly inverted after initial cold surge which intensified toward the weekend before we finally mixed out. A similar but weaker/warmer version of Dec 1968 for PDX, less snow as well.

[IbrChris]

Here is a quick and dirty comparison table I put together last December.

 

Arctic blast historical thread (SLE sounding data)

Month/Year | 850 T© | 925 T© | PDX coldest hi/lo (F)

 

Feb 2014 | -7 | -8 | 23/19 (5-12" of snow around PDX metro, three storms)

Dec 2013 | -14 | -9 | 28/12

Feb 2011 | -10 | -7 | 32/18

Nov 2010 | -12 | -9 | 30/18

Dec 2009 | -12 | -10 | 30/12

Dec 2008 | -9 | -8 | 24/20

Jan 2004 | -8 | -3 | 24/18

Dec 1998 | -18 | -13 | 24/11

Jan 1996 | -7 | -7 | 23/14

Jan 1993 | -8 | -5 | 31/22

Dec 1990 | -22 | -17 | 19/12 (coldest in SLE sounding era)

Feb 1990 | -12 | -7 | 34/20

Feb 1989 | -17 | -15 | 15/9

Nov 1985 | -11 | -9 | 25/13

Dec 1983 | -16 | -12 | 20/12

Dec 1978 | -14 | -10 | 19/13

Dec 1972 | -17 | -14 | 24/8

Dec 1968 | -10 | -6 | 14/8 (really cold in lowest 1000' AGL)

 

Estimates from NOAA ERL reanalysis (1948-2012)

 

Jan 1969 | -12 | -7 | 22/16

Nov 1955 | -16 | -12 | 25/13

Jan 1950 | -18 | -14 | 16/-3

 

Note: decimal values are rounded

[IbrChris]

The Dec 1968 blast made it down to -10c early on, then WAA kicked in aloft well before the surface temps had bottomed out on 30th Dec. This created some of the steepest low level inversions with a surface arctic airmass I have seen west of the Cascades.

 

Ok here is the sounding for Dec 31, 1968 12z SLE:

 

1015 mb | -12.8c

1000 mb | -13.4c

950 mb | -3.5c

900 mb | 2.4c

850 mb | -0.3c

800 mb | 0.0c

750 mb | 0.2c

700 mb | -2.1c

[IbrChris]

On Dec 31, 1968 PDX saw 19/9 with 1.11" of precip. The day before they had 14/8 with 0.65" of precip (all snow).

[IbrChris]

BTW, whoever chose that color palette should be shot. Jeezus.

[snow_wizard]

That list can't be complete.  No showing from Dec 1990 or Feb 1989?

 

EDIT...I see now...it's a monthly extreme list and not a top 10 list.

[SilverFallsAndrew]

Amazing how cold the 925mb temps were during the February 1989 blast. 

[IbrChris]

Interesting that the record 850mb temp is higher for January than for February and March.

 

Also seems strange that the record cold 850mb temp for January is only -18C.

If you look at the annual 850 mb temp oscillation for any station west of the Cascades the coldest mean 850 mb temp is in February or March (two reasons, one being that there's some seasonal lag aloft...peak 850 mb temps are in August. The other is due to the moderating effects of the Pacific and the fact that the water is coldest offshore in late winter/early spring and warmest in late summer).

[Karl Bonner]

If you look at the annual 850 mb temp oscillation for any station west of the Cascades the coldest mean 850 mb temp is in February or March (two reasons, one being that there's some seasonal lag aloft...peak 850 mb temps are in August. The other is due to the moderating effects of the Pacific and the fact that the water is coldest offshore in late winter/early spring and warmest in late summer).

The coldest mean temp at 850mb is in Feb/March, yet the coldest surface temps are in late December.  Wow, what a disconnect.  

 

You can't claim our seasonal lag mechanics are caused by sun angle because then all midlatitude regions should have similar lag, including similar climates like Western Europe.  But this isn't the case.  (Or you could assume W. Europe has even MORE seasonal lag up@850 than we do (April colder on average than January, maybe?!? )  For some reason we do an excellent job at accumulating relatively chilly inversiony low layers in November and December, then not so much in Jan-Feb as surface temps gradually creep up while aloft temps stay the same or even become marginally cooler...a phenomenon not reflected in other midlatitude climates.

[Deweydog]

The coldest mean temp at 850mb is in Feb/March, yet the coldest surface temps are in late December.  Wow, what a disconnect.

 

You can't claim our seasonal lag mechanics are caused by sun angle because then all midlatitude regions should have similar lag, including similar climates like Western Europe.  But this isn't the case.  (Or you could assume W. Europe has even MORE seasonal lag up@850 than we do (April colder on average than January, maybe?!? )  For some reason we do an excellent job at accumulating relatively chilly inversiony low layers in November and December, then not so much in Jan-Feb as surface temps gradually creep up while aloft temps stay the same or even become marginally cooler...a phenomenon not reflected in other midlatitude climates.

 

Yeah... you pretty much can.  

[IbrChris]

The coldest mean temp at 850mb is in Feb/March, yet the coldest surface temps are in late December.  Wow, what a disconnect.

 

You can't claim our seasonal lag mechanics are caused by sun angle because then all midlatitude regions should have similar lag, including similar climates like Western Europe.  But this isn't the case.  (Or you could assume W. Europe has even MORE seasonal lag up@850 than we do (April colder on average than January, maybe?!? )  For some reason we do an excellent job at accumulating relatively chilly inversiony low layers in November and December, then not so much in Jan-Feb as surface temps gradually creep up while aloft temps stay the same or even become marginally cooler...a phenomenon not reflected in other midlatitude climates.

 

It's fairly simple. Normally our late winter/early spring weather pattern features a trough either overhead or just offshore. The air aloft is coldest in late winter/early spring (both at 850 mb and at 500 mb) over the ocean precisely due to the heat storage capability of water vs air or the ground surface (the latter two radiate heat to achieve equilibrium with their environment much more rapidly). You'll notice 850 mb temps over maritime/oceanic regions show a seasonal lag while over continental areas they largely mirror the surface temperature profile, that is coldest in January, warmest in July. 

 

Don't get bogged down in pattern minutiae like "December inversions" or what not. As far as mean 850 mb temps we are looking solely at climatology. So while there have been some strong Dec inversions there have also been plenty of normal troughs overhead and some arctic blasts during the same time of the year. 

 

It is a well-known fact that air is a rather poor conductor of heat, especially where there are fewer molecules (with altitude). Not to mention our airmasses rarely form in-situ with the exception of lows that form just offshore. That means the air aloft is more likely advected from some distant location and simply modified in the journey from it's origin (often over Alaska or Siberia) to the PNW with the lower levels taking on a maritime characteristic while the mid and upper levels remain polar.

[Jesse]

The coldest mean temp at 850mb is in Feb/March, yet the coldest surface temps are in late December. Wow, what a disconnect.

 

You can't claim our seasonal lag mechanics are caused by sun angle because then all midlatitude regions should have similar lag, including similar climates like Western Europe. But this isn't the case. (Or you could assume W. Europe has even MORE seasonal lag up@850 than we do (April colder on average than January, maybe?!? ) For some reason we do an excellent job at accumulating relatively chilly inversiony low layers in November and December, then not so much in Jan-Feb as surface temps gradually creep up while aloft temps stay the same or even become marginally cooler...a phenomenon not reflected in other midlatitude climates.

Our January warming phenomenon, although probably very attractive to you, is fairly recent and not representative of our region's long-term climo. Things will likely start to swing back toward January being our coldest month at some point in the near future IMO. December ending up colder than January for 1981-2010 climo is a fluke that will be corrected down the road.

 

And hopefully the event a week or so ago put to rest any ridiculous notions about February's ability (or inability) to get really cold around here. Even after the arbitrary February 5th cutoff we held sacred for so many years, which again says more about recent happenstance than anything regarding our climate's capabilities.

[SilverFallsAndrew]

Our January warming phenomenon, although probably very attractive to you, is fairly recent and not representative of our region's long-term climo. Things will likely start to swing back toward January being our coldest month at some point in the near future IMO. December ending up colder than January for 1981-2010 climo is a fluke that will be corrected down the road.

 

And hopefully the event a week or so ago put to rest any ridiculous notions about February's ability (or inability) to get really cold around here. Even after the arbitrary February 5th cutoff we held sacred for so many years, which again says more about recent happenstance than anything regarding our climate's capabilities.

 

February 9th is the new cutoff!

[Karl Bonner]

I still haven't heard a good explanation for why our average daily temps bottom out so early in the season - especially in spite of all the 850mb seasonal lag - nor why our cold snaps start to trend rapidly milder after Groundhog Day.

 

Yes it is the case that January used to be the coldest calendar month.  Is the recent shift to December more of a "luck of the draw" as far as when we get our arctic blasts and inversions - or is climate change (either natural or human) somehow tweaking the shape of our seasonal temperature curve (as opposed to merely shifting the whole curve up or down)?

[SilverFallsAndrew]

I still haven't heard a good explanation for why our average daily temps bottom out so early in the season - especially in spite of all the 850mb seasonal lag - nor why our cold snaps start to trend rapidly milder after Groundhog Day.

 

Yes it is the case that January used to be the coldest calendar month.  Is the recent shift to December more of a "luck of the draw" as far as when we get our arctic blasts and inversions - or is climate change (either natural or human) somehow tweaking the shape of our seasonal temperature curve (as opposed to merely shifting the whole curve up or down)?

 

I think this is an excellent question Karl.

[BLI snowman]

November/December and February/March have actually seen more arctic events in the 1983 to present period than was seen in the previous 3-4 decades. So clearly luck has been factoring into it. It's like our climate is trying to compensate for the rash of supreme January turdfests by giving us as many late and early season events as ever before. 

[Jesse]

I still haven't heard a good explanation for why our average daily temps bottom out so early in the season - especially in spite of all the 850mb seasonal lag - nor why our cold snaps start to trend rapidly milder after Groundhog Day.

 

Yes it is the case that January used to be the coldest calendar month.  Is the recent shift to December more of a "luck of the draw" as far as when we get our arctic blasts and inversions - or is climate change (either natural or human) somehow tweaking the shape of our seasonal temperature curve (as opposed to merely shifting the whole curve up or down)?

 

We will become California. Soon.

 

Is that the answer you're looking for?

[luterra]

I still haven't heard a good explanation for why our average daily temps bottom out so early in the season - especially in spite of all the 850mb seasonal lag - nor why our cold snaps start to trend rapidly milder after Groundhog Day.

 

Yes it is the case that January used to be the coldest calendar month.  Is the recent shift to December more of a "luck of the draw" as far as when we get our arctic blasts and inversions - or is climate change (either natural or human) somehow tweaking the shape of our seasonal temperature curve (as opposed to merely shifting the whole curve up or down)?

 

I'll give it a shot...this is based on physical reasoning without looking at long term historical ridge/trough placement so could be wrong.

 

The land cools more quickly than the ocean in the fall.  Since cold air is denser than warm air this creates a tendency toward higher pressure inland.  In December this pressure difference is more frequently sufficient to overwhelm the prevailing westerlies, generating periods of low-level offshore flow.  From November through mid-February, offshore flow brings significantly colder weather than onshore flow, so it perhaps not surprising that December and January are the coldest months at the surface.  The sun angle contributes as well of course, especially as high pressure regimes may average 10-15 degrees colder than they "should" be if inversions set in.

 

At some point around Feb. 15, the land has started to warm while the ocean is just reaching its coldest temperature of the season.  This tips the balance in favor of neutral pressure gradients or offshore highs, both of which favor onshore flow.  With the upper level temps tracking ocean temps, 850 mb temperatures frequently drop into the -2 to -6 range bringing plenty of mountain snow while the valleys see warmer average temps than Dec. and Jan. since early-spring maritime air is warmer than mid-winter continental air.