Our region's extreme run

[RodneyS]

On 4/28/2020 at 6:02 PM, RodneyS said:

I just posted this on the Capital Weather Gang webpage, in response to Ian Livingston's article at https://www.washingtonpost.com/weather/2020/04/28/pm-update-some-more-showers-tonight-much-warmer-wednesday

Today marked the 15th consecutive day at DCA without a 70+ degree reading.  The only other April 14-28 period where that happened in DC weather history was 1875.  However, as Ian notes, the current run appears over, as tomorrow is forecast to be at least 70.  In 1875, the run ended one day later, on April 30th, with a reading of 72.  Still, there is a big difference between these two Aprils.  April 1875 averaged only 48.0 degrees, the second coldest April in DC history, whereas this April has averaged 54.8 so far, only slightly below the 1871-2019 historical April average of 55.3.  By the way, 1874 was the coldest April in DC history, at 47.1, and the only April day that reached 70+ that year was the 15th, at 72 degrees.

April 2020 at DCA averaged 55.3 degrees -- the same as the 1871-2019 historical average.  However, precipitation at 6.30 inches was double the DC April historical average of 3.15 inches.  In fact, it was the 7th rainiest April in DC history, with the rainiest being 9.13 inches in 1889.

[RodneyS]

On 4/28/2020 at 6:02 PM, RodneyS said:

I just posted this on the Capital Weather Gang webpage, in response to Ian Livingston's article at https://www.washingtonpost.com/weather/2020/04/28/pm-update-some-more-showers-tonight-much-warmer-wednesday

Today marked the 15th consecutive day at DCA without a 70+ degree reading.  The only other April 14-28 period where that happened in DC weather history was 1875.  However, as Ian notes, the current run appears over, as tomorrow is forecast to be at least 70.  In 1875, the run ended one day later, on April 30th, with a reading of 72.  Still, there is a big difference between these two Aprils.  April 1875 averaged only 48.0 degrees, the second coldest April in DC history, whereas this April has averaged 54.8 so far, only slightly below the 1871-2019 historical April average of 55.3.  By the way, 1874 was the coldest April in DC history, at 47.1, and the only April day that reached 70+ that year was the 15th, at 72 degrees.

 In response to a comment on the Capital Weather Gang webpage arguing that we had a normal Spring, I posted this reply at https://www.washingtonpost.com/weather/2020/05/13/warm-weather-arrive-abruptly-east-this-week-may-just-be-tease-some: I wouldn't exactly call this Spring normal, particularly for the last 30 days.  The maximum temperature at DCA during April 14-May 13 averaged 63.6 degrees, the 6th coldest all-time in DC for that period and the coldest since 1882, which averaged 62.2.  The coldest all-time was 1875, which averaged 60.8; and the warmest was 1985, which averaged 79.0.

[wxdude64]

1917 must have been a doozy! I (and all the CO-Ops within 30 miles) are running -8.5 to -10 for the month to date and the stations that have been around a while have 1917 one to 2.5 degrees colder!! Crazy.

[RodneyS]

13 hours ago, wxdude64 said:

1917 must have been a doozy! I (and all the CO-Ops within 30 miles) are running -8.5 to -10 for the month to date and the stations that have been around a while have 1917 one to 2.5 degrees colder!! Crazy.

Based on the metric I was using, 1917 wasn't quite as cold as this year in DC, with an average maximum temperature of 63.8 during April 14-May 13.  However, May 1917 maximums averaged only 68.8, 4th coldest of all time. And the overall average May 1917 temperature was only 59.6, just 0.4 degrees above the all-time coldest DC May, which was 1907.

[wxdude64]

13 hours ago, RodneyS said:

Based on the metric I was using, 1917 wasn't quite as cold as this year in DC, with an average maximum temperature of 63.8 during April 14-May 13.  However, May 1917 maximums averaged only 68.8, 4th coldest of all time. And the overall average May 1917 temperature was only 59.6, just 0.4 degrees above the all-time coldest DC May, which was 1907.

Must have been colder back here, all the stations that old or older have 1917 WAY below anything else. Several stations go back into 1890's.

[wxdude64]

So...Roanoke finally had a below 90 high today (89 lol), so that stops the streak at 29 consecutive 90 or above days. That is the new record, breaking 1966's 22 days in a row by a good bit.

[RodneyS]

On 7/30/2020 at 7:40 PM, wxdude64 said:

So...Roanoke finally had a below 90 high today (89 lol), so that stops the streak at 29 consecutive 90 or above days. That is the new record, breaking 1966's 22 days in a row by a good bit.

DCA recorded 28 90-degree-plus days this month, breaking the DC record of 25 set in July 2011.  However, the longest streak at 20 days fell one-day short of the 1980 and 1988 record streaks of 21 days.  Also, the July 2020 average temperature of 83.9 at DCA fell short of the July 2011 record average monthly temperature of 84.8, as well as the July 2012 average of 84.0.

[PrinceFrederickWx]

BWI tied for 3rd hottest November (along with 1985 and 1946) at 52.4 degrees. Only 1948 and 1931 were hotter at 53.0 and 54.7 degrees, respectively.

[RodneyS]

1 hour ago, PrinceFrederickWx said:

BWI tied for 3rd hottest November (along with 1985 and 1946) at 52.4 degrees. Only 1948 and 1931 were hotter at 53.0 and 54.7 degrees, respectively.

And DCA tied for the 4th hottest November (along with 1985) at 54.3 degrees. 2001 is # 1, at 54.8, and 1975 and 1979 are tied for 2nd at 54.4. 

[WxUSAF]

Going to extend this record another 300+ days and therefore beat the previous record by 700+ days.

 

[MN Transplant]

54 minutes ago, WxUSAF said:

Going to extend this record another 300+ days and therefore beat the previous record by 700+ days.

 

Going to need to update those gardening maps.  Maybe we can grow some tropical fruit.

[RodneyS]

9 minutes ago, MN Transplant said:

Going to need to update those gardening maps.  Maybe we can grow some tropical fruit.

In yesterday's Capital Weather Gang article,  Ian was touting this morning as the day DCA and IAD would reach their 2020-21 seasonal winter minimums.  That happened at IAD, with a morning low of 16, but failed to happen at DCA, where the seasonal minimum remains 23, which occurred on December 26th.  If these minimums hold for the remainder of the winter, they would break the seasonal high minimum records established a year ago. For DCA, that is 22, and for IAD, 15.   

[wxdude64]

36 minutes ago, RodneyS said:

In yesterday's Capital Weather Gang article,  Ian was touting this morning as the day DCA and IAD would reach their 2020-21 seasonal winter minimums.  That happened at IAD, with a morning low of 16, but failed to happen at DCA, where the seasonal minimum remains 23, which occurred on December 26th.  If these minimums hold for the remainder of the winter, they would break the seasonal high minimum records established a year ago. For DCA, that is 22, and for IAD, 15.   

Crazy the way DCA holds heat.... Course one day in early March they'll get a 19 to screw up going for 1000.

[RodneyS]

6 hours ago, wxdude64 said:

Crazy the way DCA holds heat.... Course one day in early March they'll get a 19 to screw up going for 1000.

DCA is the champion of high minimums year-round.  However, it's interesting to note that both DCA and IAD have added four degrees in the last decade to their respective high winter minimums.  Coming into 2012, DCA's record high winter minimum was 18 degrees and IAD's was 11.  Now, DCA's is 22 and IAD's is 15, with each quite possibly breaking those records by another degree this season.   

[RodneyS]

On 2/21/2021 at 2:38 PM, RodneyS said:

DCA is the champion of high minimums year-round.  However, it's interesting to note that both DCA and IAD have added four degrees in the last decade to their respective high winter minimums.  Coming into 2012, DCA's record high winter minimum was 18 degrees and IAD's was 11.  Now, DCA's is 22 and IAD's is 15, with each quite possibly breaking those records by another degree this season.   

I think it's now fair to say that both DCA and IAD have broken their high winter minimum temperature records set just last winter.  DCA's record high winter minimum temperature is now 23 degrees, and IAD's is now 16.  However, I discovered that way back in the winter of 1952-53, and more recently in the winter of 2001-02, the DCA minimum was 19.  So, that 19-degree record DCA (and DC, back to 1872) high winter minimum stood until last winter, when it was broken by three degrees. This winter, that record high minimum was broken by another degree, as was also true at IAD. 

[RodneyS]

Today has an interesting distinction, with a high of 59 at DCA, which was recorded at 12:33 AM.  Officially, that is the second lowest DC maximum ever for May 29th, with May 29, 1893 being the record-holder at 58 degrees.  However, that record is likely the result of the temperature not being observed when the day dawned, because the official DC temperature range for May 28, 1893 is 60-69 degrees. If that is correct, which I think is likely, May 29th, 1893 had to begin with a temperature of at least 60 degrees.  So today's high of 59 is likely the new unofficial record-holder for lowest DC maximum on May 29th. 

[PrinceFrederickWx]

I didn't realize August was 6th hottest at BWI.

[RodneyS]

On 12/30/2015 at 11:55 AM, Ian said:

This month yo

 

December 2021 at DCA could not match December 2015's average of 51.2 degrees, but it was the second warmest December in DC history at 47.6 degrees -- 3.6 degrees cooler, but 2.0 degree warmer than the December record holders prior to 2015, which were December 1889 and 1984 (45.6).  That also makes December 2021 the fourth warmest meteorological winter month in DC history, behind only December 2015, January 1950 (48.0), and February 2017 (47.7).

[MN Transplant]

40 minutes ago, RodneyS said:

December 2021 at DCA could not match December 2015's average of 51.2 degrees, but it was the second warmest December in DC history at 47.6 degrees -- 3.6 degrees cooler, but 2.0 degree warmer than the December record holders prior to 2015, which were December 1889 and 1984 (45.6).  That also makes December 2021 the fourth warmest meteorological winter month in DC history, behind only December 2015, January 1950 (48.0), and February 2017 (47.7).

I knew it was bad, but that is really bad.

[RodneyS]

16 hours ago, MN Transplant said:

I knew it was bad, but that is really bad.

Another interesting fact about December 2021 is that there were only 0.63 inches of precipitation at DCA -- the 6th driest December in DC history, with 1889 the driest at 0.19 inches. (1901 was the wettest December in DC at 7.56 inches).  Moreover, November and December 2021 combined totaled only 1.61 inches at DCA -- the 2nd driest November-December in DC history, with 1965 the driest November-December at 0.84 inches. (2018 was the wettest November-December in DC at 13.39 inches, and was also the wettest year overall, at 66.28 inches).  However, unlike 1965, which was the second driest year overall in DC at 26.94 inches (1930 was the driest, at 21.66), 2021 was relatively wet overall, at 44.09 inches (tied with 1912 for 47th wettest out of 151 years).

[WinterFire]

Despite having gone from 28 to 30 (??) between 6-7pm, the forecast minimum at DCA tonight is 18, which would be the coldest since Feb 2, 2019. Can we get there???
 

Still waiting on true Arctic air for a sub-30 degree high temp. Last sub-30 day at DCA: Feb 1, 2019, but I’m hopeful we will see that in the next couple weeks. (As a side note, we’re still waiting on the first sub-40 high temp at DCA, but that seems pretty given for tomorrow)

[RodneyS]

On 1/3/2022 at 7:30 PM, WinterFire said:

Despite having gone from 28 to 30 (??) between 6-7pm, the forecast minimum at DCA tonight is 18, which would be the coldest since Feb 2, 2019. Can we get there???
 

Still waiting on true Arctic air for a sub-30 degree high temp. Last sub-30 day at DCA: Feb 1, 2019, but I’m hopeful we will see that in the next couple weeks. (As a side note, we’re still waiting on the first sub-40 high temp at DCA, but that seems pretty given for tomorrow)

Today's average temperature of 26 at DCA (high of 30, low of 22) was the lowest since February 1, 2019's average of 22 (high of 24, low of 20).  The 30 degree high was also the lowest since Feb 1, 2019's high of 24. 

[RodneyS]

On 1/11/2022 at 6:42 PM, RodneyS said:

Today's average temperature of 26 at DCA (high of 30, low of 22) was the lowest since February 1, 2019's average of 22 (high of 24, low of 20).  The 30 degree high was also the lowest since Feb 1, 2019's high of 24. 

The temperature this morning at DCA made it down to 17 degrees, the lowest there since the 10 degree low of January 31, 2019.

[peribonca]

Anyone with end of month data for January? Definitely felt chilly!

[MN Transplant]

16 hours ago, peribonca said:

Anyone with end of month data for January? Definitely felt chilly!

The Feb obs thread has it.  It was chilly, and the numbers would be more impressive if you took out Jan 1-2 which were way above normal.

[RodneyS]

12 hours ago, MN Transplant said:

The Feb obs thread has it.  It was chilly, and the numbers would be more impressive if you took out Jan 1-2 which were way above normal.

January 2022 at DCA averaged 34.6 degrees, which was 2.9 degrees below the new 1991-2020 normal and 0.7 degrees below the 1871-2022 DC historical January average.  It was also the coldest month at DCA since February 2015, which averaged only 30.3 degrees.  Perhaps the most unusual aspect ot January 2022 at DCA was that the temperature there was 13.0 degrees below December 2021 -- the 5th largest decline in DC history for those two months, with December 2015 to January 2016 being the largest, at 16.3 degrees.

[RodneyS]

I just posted this on the Capital Weather Gang page:

Yesterday, DCA recorded the largest decline in daily high temperature this century.  The high on Wednesday was 77, but it plummeted to 42 yesterday, for a decline of 35 degrees.  That was the largest since December 23, 1998, when the high temperature declined by 39 degrees -- from 67 on December 22nd to 28 on December 23rd.  The largest daily high temperature decline in DC history occurred on March 19, 1934, when the decline was 41 degrees -- from 78 on March 18th to 37 on March 19th.

Also, yesterday's decline in daily average temperature of 22 degrees at DCA -- from 59.5 on Wednesday to 37.5 yesterday -- was the largest since February 9, 2017, when average temperature declined by 23.5 degrees -- from 62.5 on February 8th to 39 on February 9th.  The largest daily average temperature decline in DC history occurred on January 29, 1934, when the decline was 28 degrees -- from 49.5 on January 28th to 21.5 on January 29th.

 

[MN Transplant]

3 hours ago, RodneyS said:

I just posted this on the Capital Weather Gang page:

Yesterday, DCA recorded the largest decline in daily high temperature this century.  The high on Wednesday was 77, but it plummeted to 42 yesterday, for a decline of 35 degrees.  That was the largest since December 23, 1998, when the high temperature declined by 39 degrees -- from 67 on December 22nd to 28 on December 23rd.  The largest daily high temperature decline in DC history occurred on March 19, 1934, when the decline was 41 degrees -- from 78 on March 18th to 37 on March 19th.

Also, yesterday's decline in daily average temperature of 22 degrees at DCA -- from 59.5 on Wednesday to 37.5 yesterday -- was the largest since February 9, 2017, when average temperature declined by 23.5 degrees -- from 62.5 on February 8th to 39 on February 9th.  The largest daily average temperature decline in DC history occurred on January 29, 1934, when the decline was 28 degrees -- from 49.5 on January 28th to 21.5 on January 29th.

 

Good stuff, Rodney.

[RodneyS]

4 hours ago, MN Transplant said:

Good stuff, Rodney.

Thanks.  In doing the search for largest daily average temperature declines, I found some inconsistencies in the data. At first, I thought the largest decline occurred on January 13, 1895, as the average temperature that day is listed as 9.0 degrees, with January 12, 1895 listed as 37.5 degrees.  However, I then saw that the listed range on the 12th is 27 to 48, whereas the listed range on the 13th is 4 to 14.  So, presumably what happened is that the Weather Bureau employee was at his station for a good portion of the day on the 12th, but left well before midnight with the temperature falling.  By midnight, it may have been say, 20, but no one was there to record it.  By the time he arrived on the 13th, the temperature was between 4 and 14, and so that's what he recorded, but the true range on the 12th would have been 20 to 48 (average 34), and the true range on the 13th would have been 4 to 20 (average of 12), and so the actual decline would have been only 22 degrees.  I'm not sure when an automated temperature recorder was used in DC, but I believe all those anomalies occur prior to 1900.    

[MN Transplant]

3 hours ago, RodneyS said:

Thanks.  In doing the search for largest daily average temperature declines, I found some inconsistencies in the data. At first, I thought the largest decline occurred on January 13, 1895, as the average temperature that day is listed as 9.0 degrees, with January 12, 1895 listed as 37.5 degrees.  However, I then saw that the listed range on the 12th is 27 to 48, whereas the listed range on the 13th is 4 to 14.  So, presumably what happened is that the Weather Bureau employee was at his station for a good portion of the day on the 12th, but left well before midnight with the temperature falling.  By midnight, it may have been say, 20, but no one was there to record it.  By the time he arrived on the 13th, the temperature was between 4 and 14, and so that's what he recorded, but the true range on the 12th would have been 20 to 48 (average 34), and the true range on the 13th would have been 4 to 20 (average of 12), and so the actual decline would have been only 22 degrees.  I'm not sure when an automated temperature recorder was used in DC, but I believe all those anomalies occur prior to 1900.    

Yeah, that is clearly an error.  Nice find.