Early January 2014 cold snaps - featuring the polar vortex of doom

[usedtobe]

I have a spreadsheet of all the DCA temps.. famartin sent me DCA/BWI/IAD a few years ago.  I just made a column for AVG. 

Could you send it to me? 

[Ian]

Could you send it to me? 

Sure, though I need to clean it up a little. I have the last two years in a separate section etc.. Good reason to force myself to do that.  Give me a few days if you can.

[usedtobe]

1970    1/9/1970    12

1971    2/1/1971    22

1972    1/16/1972    18

1973    1/8/1973    24

1974    1/13/1974    33

1975    1/14/1975    31

1976    1/18/1976    24

1977    1/17/1977    18

1978    1/10/1978    23

1979    2/18/1979    15

1980    3/1/1980    21

1981    1/12/1981    22

1982    1/17/1982    10

1983    12/25/1983    14

1984    1/21/1984    20

1985    1/21/1985    17

1986    1/28/1986    23

1987    1/25/1987    17

1988    1/6/1988    20

1989    12/22/1989    17

1990    2/26/1990    31

1991    1/22/1991    26

1992    1/19/1992    25

1993    12/28/1993    25

 

Here's the whole record in a graph with lows too:

 

Untitled-5.gif

That figure reminds me that in the early 70s we wondered whether DCA could ever drop below zero again because of the UHI.  We did.  Now we are in another long no zero min stretch.

[gymengineer]

Really interesting data, Ian. There were so many more years with highs in the teens at DCA in the 1970's and 1980's as compared to post 1994. 

[Ian]

That figure reminds me that in the early 70s we wondered whether DCA could ever drop below zero again because of the UHI.  We did.  Now we are in another long no zero min stretch.

This is one of those stats where the location change probably did have a sizable difference especially before major development of the whole area in recent decades.  No doubt it's tougher to get below zero right on the river than somewhere else especially if it's ice free etc.  Zero may just not be very common where the sensor is now.. not that it ever was truly common before.  Even Balt has considerable trouble compared to Dulles (or pre 1990s Dulles). 

[usedtobe]

Sure, though I need to clean it up a little. I have the last two years in a separate section etc.. Good reason to force myself to do that.  Give me a few days if you can.

Sure, I'd appreciate it,  might help with my outlooks when they look extreme (either torch or iceberg cold) giving me a feel for the general possibilities.  Matt Rogers helped some with this cold as did Jay Hanna but I'd like to be able to look closer on my own.

[usedtobe]

This is one of those stats where the location change probably did have a sizable difference especially before major development of the whole area in recent decades.  No doubt it's tougher to get below zero right on the river than somewhere else especially if it's ice free etc.  Zero may just not be very common where the sensor is now.. not that it ever was truly common before.  Even Balt has considerable trouble compared to Dulles (or pre 1990s Dulles). 

This will be a true test as Monday night Tuesday is an advection cold and back in the past, DCA's low was not that different than IAD's or BWI's with strong advection.  We used to lose out badly on radiation nights like we had with this last cold shot.  It will be interesting to see how different DCA is from my reading MOnday morning.

[Ian]

This will be a true test as Monday night Tuesday is an advection cold and back in the past, DCA's low was not that different than IAD's or BWI's with strong advection.  We used to lose out badly on radiation nights like we had with this last cold shot.  It will be interesting to see how different DCA is from my reading MOnday morning.

Yes.. we seem to do better lately on windy CAA nights vs still ones of late, at least in the city.  That may keep places west from reaching full potential if it was the same air mass with snow cover radiating but should help here. Though Wed morning could have some good lows too especially west.

[grhqofb5]

I remember 1/19/1994.  Thermometer on my parents deck froze at -4 in Gaithersburg, didn't move the entire day.  Guess it made it up to around 8.  Coldest "high" in my lifetime.  Remember my friend's Italian mother yelling at me to go inside because it was dangerously cold.

[ravensrule]

This is one of those stats where the location change probably did have a sizable difference especially before major development of the whole area in recent decades.  No doubt it's tougher to get below zero right on the river than somewhere else especially if it's ice free etc.  Zero may just not be very common where the sensor is now.. not that it ever was truly common before.  Even Balt has considerable trouble compared to Dulles (or pre 1990s Dulles). 

Baltimore's coldest temperature ever recorded was -7 do you know what DCA and IAD's are?.

[Ian]

Baltimore's coldest temperature ever recorded was -7 do you know what DCA and IAD's are?.

Dulles is -18, 1/22/1984

DC is -15, 02/11/1899

DCA is -5, 1/17/1982

[WEATHER53]

It's simple and I have lived it. Few night ago when I hit 6.5 and so many other areas , probably 98%+ of the square footage of DC metro area, were in the single digits DCA was 17. In the 70's into the 80's DCA would have had a min of 11/12 and in the 50's 60's probably 9/10. The river is another excuse and basically you only have to make excuses when something is wrong or all evidence appears so. Annapolis is on the Bay, it does not do this.

Good luck trying to interview someone at DCA about this. They will refer you to the FAA, the FAA will refer you to NWS.

It has not been done on purpose, it just slipped nicely into the AGW debate and no effort will be made to rectify it.

Establish a station in the 1880's move it many times with no accounting/adjustment for that, take an area that is over 50% marsh and build it out entirely and make no accounting/adjustment for that and have what you have now.

Imagine a station that was established as official and all around it was buildings. The buildings get torn down and a huge lake is built all around the site. Do you think there would be a change in temperatures and do you think some effort would be made to account/adjust for that?

[snow.]

It's simple and I have lived it. Few night ago when I hit 6.5 and so many other areas , probably 98%+ of the square footage of DC metro area, were in the single digits DCA was 17. In the 70's into the 80's DCA would have had a min of 11/12 and in the 50's 60's probably 9/10. The river is another excuse and basically you only have to make excuses when something is wrong or all evidence appears so. Annapolis is on the Bay, it does not do this. Good luck trying to interview someone at DCA about this. They will refer you to the FAA, the FAA will refer you to NWS. It has not been done on purpose, it just slipped nicely into the AGW debate and no effort will be made to rectify it. Establish a station in the 1880's move it many times with no accounting/adjustment for that, take an area that is over 50% marsh and build it out entirely and make no accounting/adjustment for that and have what you have now. Imagine a station that was established as official and all around it was buildings. The buildings get torn down and a huge lake is built all around the site. Do you think there would be a change in temperatures and do you think some effort would be made to account/adjust for that?

 

98% is incorrect.  We have been over this for years and i am not sure where you want to move it.  We have BWI and IAD to help represent.  Andrews might help.  I think if we want to move it and I am for it, we'd need to find a place to move it.  Arboretum isn't a bad idea, but i think those looking for a substantial change if it is moved into DC proper will be sorely disappointed. IAD has suffered similarly.  They would have been -5  20 years back.  We will never see the -18's that IAD put up in the 1980s.  I also think it is important to get the facts right before making a case. Often your allegations over the years with respect to DCA are simply wrong, and have consistently been proven as such.  Most recently you got bothered by a big overnight spike at DCA, that was actually worse at every other station.  These concerns that are factually wrong, dont help a case to move it.  

[Yeoman]

I think the official site should be moved to WTOP.. it's my go-to weatherbug site when I start to get nervous about temps in the city

[WEATHER53]

Like I said-excuses, which is all you continue to offer. I have lived here since the 70's and have kept extensive and comparative records. I doubt you have. Temperatures should be pure and unadultereated. Add substantical concrete, macadam, buildings, people, cars and the always elusive "just where is DCA's equipment anyway" and temperatures will be Forced higher. Your marraige to "All is OK at DCA" is unsupportable. IAD, BWI, Andrews, Ft Belvoir have had some artifically added spikes to their ercording but they still makes sense, 17 for DCA does not make sense when everything else is 5-10

[gymengineer]

Like I said-excuses, which is all you continue to offer. I have lived here since the 70's and have kept extensive and comparative records. I doubt you have. Temperatures should be pure and unadultereated. Add substantical concrete, macadam, buildings, people, cars and the always elusive "just where is DCA's equipment anyway" and temperatures will be Forced higher. Your marraige to "All is OK at DCA" is unsupportable. IAD, BWI, Andrews, Ft Belvoir have had some artifically added spikes to their ercording but they still makes sense, 17 for DCA does not make sense when everything else is 5-10

Stop being so angry all the time. Matt is the only one willing to engage with you anymore on this topic in good faith and you just continue to miss his reasoning. Go ahead and try to prove that downtown DC fell to 5-10 F Saturday morning.

Do you even know Matt's low on Saturday morning south of DCA? It sure wasn't less than 10 F either.

[snow.]

Like I said-excuses, which is all you continue to offer. I have lived here since the 70's and have kept extensive and comparative records. I doubt you have. Temperatures should be pure and unadultereated. Add substantical concrete, macadam, buildings, people, cars and the always elusive "just where is DCA's equipment anyway" and temperatures will be Forced higher. Your marraige to "All is OK at DCA" is unsupportable. IAD, BWI, Andrews, Ft Belvoir have had some artifically added spikes to their ercording but they still makes sense, 17 for DCA does not make sense when everything else is 5-10

 

You continue to be wrong...we continue to support corrective facts, and the cycle continues....an Urban heat island is not going to radiate....I am all for moving the station as i have said many many times. And I agree an UHI will have temps that are forced higher as everyone can agree. All I am saying is be careful where you move it.  A move into DC isn't going to help.  I have lived in DC for 15 years.  I know it quite well. 

 

Nobody even really knows what you are suggesting be done?  so feel free to make a suggestion where to move it.  If you don't think IAD has been artificially spiked by Heat Island the last 20 years.  I know DC quite well.  

[snow.]

Stop being so angry all the time. Matt is the only one willing to engage with you anymore on this topic in good faith and you just continue to miss his reasoning. Go ahead and try to prove that downtown DC fell to 5-10 F Saturday morning.

Do you even know Matt's low on Saturday morning south of DCA? It sure wasn't less than 10 F either.

 

It was 16..most of the city was 15-18 other than far NW....I dont get Howard anymore...We all AGREE UHI exists...I dont know what his issue is....DCA is artificially inflated by being a heat island...Nobody is disputing that....I am for moving it....But the question is where do you move it...A move back to 24th and M will solve absolutely nothing....Andrews might be a good choice

[BTRWx]

You continue to be wrong...we continue to support corrective facts, and the cycle continues....an Urban heat island is not going to radiate....I am all for moving the station as i have said many many times. And I agree an UHI will have temps that are forced higher as everyone can agree. All I am saying is be careful where you move it.  A move into DC isn't going to help.  I have lived in DC for 15 years.  I know it quite well. 

 

Nobody even really knows what you are suggesting be done?  so feel free to make a suggestion where to move it.  If you don't think IAD has been artificially spiked by Heat Island the last 20 years.  I know DC quite well.  

On the page of my CWG writeup about the New England storm Friday I added something in the comment section about how the NYC multiple stations may be a good option for D.C. Keep KDCA for climo, but also add one on the other side of the Potomac River and one closer to the heart of downtown.

[gymengineer]

It was 16..most of the city was 15-18 other than far NW....I dont get Howard anymore...We all AGREE UHI exists...I dont know what his issue is....DCA is artificially inflated by being a heat island...Nobody is disputing that....I am for moving it....But the question is where do you move it...A move back to 24th and M will solve absolutely nothing....Andrews might be a good choice

He's going to yell at me to get off his lawn

I think as long as people resist the urge to rank things, there's less need to move sites.

[Yeoman]

I have a feeling this coming snap is going to underperform immensely 

[MN Transplant]

That graph correlates pretty well to the amount of development that's taken place in the Dulles area in the last 20 years. I don't know exactly where Dulles's readings are taken, but there are definitely edges of the airport that wouldn't be directly affected by being on/near concrete, though I assume temps would be moderated somewhat just due to all the concrete within a couple miles of the airport no matter where the station is located.

I wonder how that graph correlates to below zero readings at regional sites that aren't affected by UHI or UHI-like effects. Is it all UHI-related, or is it also a reflection of a change in global climactic regimes during that time?

 

There may be some UHI at IAD, but the development out there isn't very dense and the station is not near much of anything.

 

Yeah that's a good question in second para. I think all three local sites are UHI impacted so it's hard to tell if it's just that or climate change. I guess you'd need to look at places in the Apps etc. My guess is the frequency is down there too but perhaps not as much.

This is big cold no doubt but even for the upper Midwest for this to be the coldest since the 1990s must indicate we've had less cold in the past 20 years or so overall.

 

Yeah, there's a reason why all of the news stories have been talking about the coldest outbreak in 20 years.  Its because it hasn't been very cold in the last 20 years!

 

So far in MN, forecast highs had to be raised in the morning update, so the initial push into MN is under-performing just a bit. 

 

Grand Forks and Fargo ended up about 6 or 7 degrees higher than GFS MOS.  Minneapolis was supposed to have two straight teens below zero  highs, but they were in the middle single digits below today.

 

It's simple and I have lived it. Few night ago when I hit 6.5 and so many other areas , probably 98%+ of the square footage of DC metro area, were in the single digits DCA was 17. In the 70's into the 80's DCA would have had a min of 11/12 and in the 50's 60's probably 9/10. The river is another excuse and basically you only have to make excuses when something is wrong or all evidence appears so. Annapolis is on the Bay, it does not do this. Good luck trying to interview someone at DCA about this. They will refer you to the FAA, the FAA will refer you to NWS. It has not been done on purpose, it just slipped nicely into the AGW debate and no effort will be made to rectify it. Establish a station in the 1880's move it many times with no accounting/adjustment for that, take an area that is over 50% marsh and build it out entirely and make no accounting/adjustment for that and have what you have now. Imagine a station that was established as official and all around it was buildings. The buildings get torn down and a huge lake is built all around the site. Do you think there would be a change in temperatures and do you think some effort would be made to account/adjust for that?

 

There's nothing wrong with DCA.  It is warmer because it sites in the river and is right in the middle of the urban zone.  I was 13 the other night and on these cold nights I am closer to DCA than IAD.

 

As far as AGW, there are many other types of observations that show warming.  DCA and other urban temps are not needed to show the rise.

[Ian]

It's simple and I have lived it. Few night ago when I hit 6.5 and so many other areas , probably 98%+ of the square footage of DC metro area, were in the single digits DCA was 17. In the 70's into the 80's DCA would have had a min of 11/12 and in the 50's 60's probably 9/10. The river is another excuse and basically you only have to make excuses when something is wrong or all evidence appears so. Annapolis is on the Bay, it does not do this. Good luck trying to interview someone at DCA about this. They will refer you to the FAA, the FAA will refer you to NWS. It has not been done on purpose, it just slipped nicely into the AGW debate and no effort will be made to rectify it. Establish a station in the 1880's move it many times with no accounting/adjustment for that, take an area that is over 50% marsh and build it out entirely and make no accounting/adjustment for that and have what you have now. Imagine a station that was established as official and all around it was buildings. The buildings get torn down and a huge lake is built all around the site. Do you think there would be a change in temperatures and do you think some effort would be made to account/adjust for that?

 

As far as I know DCA is not included in most "official" AGW related research. No one here has used it to prove AGW although it clearly fits in with trends that seem to show up at all stations just about. 

 

That specific location always being a warm outlier is going to be more noticeably impacted on the edges than other places in most cases.  It's not just a DCA thing.

 

 

Also, almost every long term climate station is threaded from multiple locations.

[Yeoman]

There may be some UHI at IAD, but the development out there isn't very dense and the station is not near much of anything.

 

IAD minimum average temps have been increasing pretty significantly over the past 15 years..

 

Here's a pretty good article from CWG 

 

http://www.washingtonpost.com/blogs/capital-weather-gang/wp/2013/11/21/inside-washington-d-c-s-urban-heat-island-effect/

[gymengineer]

There may be some UHI at IAD, but the development out there isn't very dense and the station is not near much

But the air masses in 1/84 and 1/87 weren't -17, -18 F air masses either... So something about IAD is just different now. On a clear, calm, post snow night that is a lower teens night in DCA, we would no longer expect IAD to plunge well below zero.

[MN Transplant]

But the air masses in 1/84 and 1/87 weren't -17, -18 F air masses either... So something about IAD is just different now. On a clear, calm, post snow night that is a lower teens night in DCA, we would no longer expect IAD to plunge well below zero.

 

We haven't exactly been able to test that.  Since 1997, there have been exactly two days were IAD had snow on the ground and DCA had a low <13 degrees.  

[gymengineer]

We haven't exactly been able to test that.  Since 1997, there have been exactly two days were IAD had snow on the ground and DCA had a low <13 degrees.  

Yeah, that's true. But, my guess is that the area-- not just the immediate IAD area, but all the surrounding communities now--- no longer really support the forays into the negative teens. I know you're saying it's probably not as much due to UHI, but I think it's UHI that keeps a site like IAD from radiating down to -15 F in a not-super-cold air mass. Another way of saying this is that Montgomery County, MD sites like Rockville or Gaithersburg, MD, did not drop that low during 1/87 nor 1/84. Dulles was really kind of a "country" location back then... 

[WinterWxLuvr]

As far as I know DCA is not included in most "official" AGW related research. No one here has used it to prove AGW although it clearly fits in with trends that seem to show up at all stations just about.

That specific location always being a warm outlier is going to be more noticeably impacted on the edges than other places in most cases. It's not just a DCA thing.

BdPs8NJCIAA1geH.png

Also, almost every long term climate station is threaded from multiple locations.

The past 20-24 years would have an interesting best fit line.

[Sparky]

This will be a true test as Monday night Tuesday is an advection cold and back in the past, DCA's low was not that different than IAD's or BWI's with strong advection.  We used to lose out badly on radiation nights like we had with this last cold shot.  It will be interesting to see how different DCA is from my reading MOnday morning.

advection cold is usually when my location gets really low, unlike on calm clear nights.

[HighStakes]

Looks like IAD had another incredible run of low minimum in Jan. 88. They hit 12 degrees or lower 10 out 12 days from the 5th to 16th. Lowest reading in that period was -5 but nothing absurd like the 84 and 87 readings.