RodneyS

DCA _ NYC _ BOS __ ORD _ ATL _ IAH __ DEN _ PHX _ SEA 0.4 0.7 0.6 1.1 -0.4 2.1 0.5 -0.3 -0.2

February 2025 at DCA ended warm, bringing the average temperature to 41.0 degrees -- tied for the 34th warmest February in DC history. That brought the 2024-25 meteorological winter (December, January, and February) average to 39.0 degrees -- tied for the 43rd warmest in DC history. Nonetheless, the 2024-25 DCA meteorological winter was the coldest in 10 years -- surpassing every winter for cold since the 2014-15 winter averaged 36.7 degrees. The historical average for all 154 DC winters since recordkeeping began in 1871-72 is 37.1 degrees.

FYI, each of the four airports recorded only a trace of snow today. However, I am updating the table to show that -- barring corrections to the snow totals -- two more contestants have been eliminated from contention, to bring that total to 50 (in red), leaving only 19 who still have a chance to win. Most stunningly, I have determined that co-leader @mattie g has bitten the dust. Why is that? Because while he could still finish in a first-place tie with @HighStakes, he would lose the tiebreaker based on his forecast of 8.6 inches of snow at Salisbury (SBY) vs High Stake's forecast of 10.8 inches there. Because SBY has already recorded 17.8 inches this season, mattie g is history -- just as the other 49 of us are.

Thanks - - see updated table below, which also includes another 0.1 at DCA:

We have a new leader, as RIC has already recorded 2.0 inches today. That puts @mattie gin first place, with @HighStakesa big threat to move into a tie before day's end and @southmdwatcherlurking if RIC records several more inches.

Yes, and this season may make it 15 times. By the way, the largest amount by which DCA snow exceeded BWI snow was 5.5 inches in 1979-80 -- 20.1 inches at DCA, 14.6 at BWI. On the other hand, the largest amount by which BWI snow exceeded DCA snow was 20.9 inches in 2009-10 -- 77.0 inches at BWI and 56.1 inches at DCA. Both totals were record-breakers for any year in Baltimore and DC dating back to the 1880s, and the BWI total even exceeded IAD's record-breaking total of 73.2 inches that memorable snow season 15 years ago.

DCA became the official DC weather location in July 1945, and BWI began operations in June 1950. Thus, winter season comparisons between the two airports begin in 1950-51, and so there are now 74 winter season comparisons in the books. During those 74 seasons, DCA has averaged 15.5 inches of snow, and BWI has averaged 19.8 inches, with BWI snow exceeding DCA snow 58 times, DCA snow exceeding BWI snow 14 times, and two seasons ending in a tie.

Thanks. What I was going by was Wednesday's daily report for DCA issued at 12:35 AM this morning, which may be found at "Observed Weather" "Daily Climate Report" for "Washington-National" at https://www.weather.gov/wrh/Climate?wfo=lwx. The newest version is currently for Thursday, but you can find the 12:35 AM version for Wednesday by clicking "2" at the top (in blue). It's head-scratching how these contradictions occur, but you are correct that the snow total for yesterday is now back up to 0.5 inches. The below table reflects that change for DCA:

The DCA measuring gurus have helped you and a number of other folks by revising downward yesterday's snow total there from 0.5 to 0.3 inches. It would be interesting to know how these revisions come about -- perhaps some of the gurus don't realize that you are not supposed to take snow away from the measuring location to make a snowman? In any event, here is the slightly revised leaderboard, subject to further revisions without warning. P.S. I have listed in red all of the unfortunates who have been eliminated . . . whoops, that includes me.

Don't shortchange yourself, @snowfan -- you are currently 12th. Unfortunately, because you have all negative departures, your chance of winning are the same as mine and 38 others -- zero.

You aren't out yet, @nw baltimore wx. Your only negative departure is DCA, but the entrants ahead of you aren't doing well there either, and so if you nailed the other three airports you would win.

Apparently RIC did receive only 1.0 inch in this storm. However, I was 0.1 over the total at IAD, and so this revision corrects that. Quite a shakeup on the leaderboard, with some unexpected contenders this season. Yes, @Roger Smith, I say that with you in mind. Now, if @George BM gets into contention, @Jebmanwill be wondering why he did not enter.

The latest snow totals that I have for the February 11-12th storm are: BWI 3.8, DCA 6.4, IAD 4.9, and RIC 1.0. However, the latter total is likely incomplete, as for some reason the current Wakefield, VA report gives totals for every tiny town, but not RIC. Maybe @RIC Airportknows? Our new leader is @mappy

Thanks, Roger. See updated table below

An illustration of how anomalous the period January 12th-22nd at DCA has been in recent years can be seen by comparing the 1991-2020 daily temperature normals for each day of the year (minus February 29th) calculated by the National Centers for Environmental Information (NCEI), with the actual daily averages during that 30-year period. By far the two largest daily negative anomalies (averages are below the normals) for the calendar year are for January 21st-22nd, and by far the two largest positive anomalies (averages are above the normals) for the calendar year are for January 12th-13th. The below list shows the Top Ten daily temperature anomalies (daily average minus daily normal) at DCA during 1991-2020. It can be seen immediately that there is nothing comparable to the period January 12th-22nd. December 8th-9th has consecutive negative anomalies of -3.28 and -2.97 degrees at DCA, but the largest consecutive December positive anomalies there are not listed below because they are only 1.13 and 2.15 degrees, respectively, on December 22nd-23rd. 1) January 21st -4.43 degrees 2) January 13th +4.37 degrees 3) January 12th +4.32 degrees 4) January 22nd -4.20 degrees 5) February 13th -3.78 degrees 6) December 8th -3.28 degrees 7) March 4th -3.20 degrees 8) April 29th -3.02 degrees 9) December 9th -2.97 degrees 10) April 5th -2.92 degrees I believe that the most plausible explanation here is that the DCA 1991-2020 temperature "normals" calculated by the NCEI for January 12th-13th and January 21st-22nd are not truly normals in any meaningful sense, but are simply the end product of a mathematical process based upon there being no known reason for temperatures on those four calendar days to deviate so significantly from temperatures on nearby calendar days. However, if a reason were to be found, the NCEI would likely have to increase the DCA January 12th-13th normals by about four degrees each and decrease the January 21st-22nd DCA normals by about four degrees each.