RodneyS

Thanks, but I need a number for RIchmond.

It would appear that integrating AI with traditional models could improve the latter. For example, if AI is forecasting snowstorms for a given area more accurately than traditional models, that may indicate that traditional models are paying insufficient attention to historical data that could inform the models.

Thanks.

Okay, but I need a tiebreaker for only one of the two airports, in the event that you and another contestant tie for 1st place when the contest ends. So, why don't you choose from one of these two midpoints: Lynchburg 13.5 inches or Salisbury 10.5 inches?

Do you have a tiebreaker for Salisbury or Lynchburg?

Do you have a tiebreaker (either Salisbury or Lynchburg)?

That would put @EastCoast NPZin a tight spot.

That pick last year would have won easily.

A repeat of Feb 5-6, 2010?

It's time for the 9th annual Mid-Atlantic snowfall contest! Those who participated last year will doubtless recall the excitement of that contest in which measurable snow managed to fall at BWI International (BWI), Reagan National (DCA), and Dulles International (IAD) on exactly one day -- February 1st. And even that did not happen at Richmond International Airport (RIC), where the snow gods pitched a shutout. However, we all know things will be different this time around because it is not a La Nina, but rather an El Nino, snow season. And an El Nino has never produced at DCA less snow than . . . one-tenth of an inch. (1972-73 and 1997-98). Then again, the El Nino winter of 2009-10 set the all-time DC snow record of 56.1 inches. So, that narrow range should assist with your pick. Everyone is encouraged to play, including lurkers, new members, and people outside the region. Please note that you are forecasting the total snowfall for the entire snow season (NOT just Dec/Jan/Feb) to the nearest one-tenth of an inch for the four major Mid-Atlantic airports: BWI, DCA, IAD, and RIC. Generally, snow does not fall after early April at any of these airports, and so the contest is usually finalized by early to mid-April. For the tiebreaker, please choose one of the following two airports: Salisbury, MD (SBY) or Lynchburg, VA (LYH). Choose only one -- in the event of the tiebreaker, the difference at the airport you chose will be compared with the difference at the airport your opponent(s) chose. The winner will be the person who has the lowest combined absolute value departure for all four airports. For example, if you forecast: BWI: 0.0" DCA: 0.0" IAD: 0.0" RIC: 10.0" And the actual seasonal totals turn out to be: BWI: 2.5" DCA: 2.5" IAD: 2.5" RIC: 2.5" Your absolute value departures would be: BWI: 2.5 DCA: 2.5 IAD: 2.5 RIC: 7.5 Thus, your total departure would be 15.0. Please use the following format when posting your forecast, in this order: BWI: DCA: IAD: RIC: Tiebreaker (SBY or LYH): The deadline for entries is Friday, December 1, at 11:59pm. You are welcome to update your forecast at any time up to the deadline. However, please do not edit your original post -- either submit a new post or send me a private message. If there's any accumulating snow before the deadline, please include that in your forecast as well. I think the best approach is to submit your forecast in advance of the deadline and update if necessary, just in case you get tied up on December 1st, when the contest will lock -- no late entries will be accepted. The winner gets an E-trophy made of snow and an induction into the Hall of Fame with the previous winners: 2015-16: @Shadowzone 2016-17: @Stormpc 2017-18: @olafminesaw 2018-19: @olafminesaw (tiebreaker win against @Stormpc 2019-20: @Prestige Worldwide 2020-21: @NorthArlington101 2021-22: @IUsedToHateCold 2022-23: @LittleVillageWx Good luck everyone!

October 2023 at DCA came in above the 1991-2020 normal, at 63.1 degrees, which was higher than October 2012 (61.0), but lower than October 2017 (64.9). So, the first 10 months of 2023 gained on 2012, but fell behind 2017, with an average temperature of 64.0 degrees versus 64.7 for the first 10 months of 2012 and 64.1 for the first 10 months of 2017. 2023 could still be the warmest year ever in DC, if it were to average about 50 degrees during November and December. Under that circumstance, the final two months of 2023 would be the third warmest ever, behind only 2015 (52.5) and 2001 (50.2).

DCA_NYC_BOS__ ORD_ATL_IAH__ DEN_ PHX_ SEA -1.1 0.1 0.1 -0.3 -1.4 0.7 -0.7 0.1 0.9

September 2023 at DCA came in above the 1991-2020 normal, at 73.4 degrees, which was higher than both September 2012 (72.2) and September 2017 (72.6). So, the first nine months of 2023 gained on both 2012 and 2017, with an average temperature of 64.1 degrees versus 65.1 for the first nine months of 2012 and 64.0 for the first nine months of 2017. Thus, while 2023 is averaging about a degree cooler per day than 2012 did during its first nine months, 2023 is averaging a tad warmer than 2017 did during its first nine months.

DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA -0.3 0.5 1.0 1.7 -0.8 2.5 1.0 -0.6 0.6

Awesome job for many years, Roger -- many thanks.

A remarkable 4-day run at Dulles. In the 60 Septembers prior to 2023 at IAD, only three 99-degree readings had been recorded, with no September day exceeding 99. Beginning Sunday (9-3-2023), we have reached 99, 99, 99, and 100 on consecutive days.

August 2023 at DCA came in below the 1991-2020 normal, at 78.7 degrees, which was lower than August 2012 (81.0), but higher than August 2017 (77.4). So, the first eight months of 2023 slipped further behind 2012, with an average temperature of 62.96 degrees versus 64.22 for the first eight months of 2012. However, that 62.96 was barely below the 62.97 for the first eight months of 2017.

DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA 1.3 1.9 1.3 3.0 0.0 3.6 3.6 0.4 0.1

Time for another update. Rainfall at DCA on August 12th has gone missing recently, as the last three years have totaled zero, a trace, and zero. On the other hand, rainfall the last three years on August 15th has totaled 0.24, 0.01, and 0.38 inches. However, no major storms have occurred on August 15th, and so the Top 10 rainiest days in DC history on August 12th or 15th remain entirely on August 12th. In the 13 years since I began tracking the difference in official DC precipitation on these two days, the major disparity that I found during 1871-2010 had not continued, which might suggest that disparity was an aberration. However, 13 years is too short a time period to conclude that, especially since August 12th has continued to be slightly wetter than August 15th, even though August 15th has recorded a few more rainy days during that recent period. Specifically, here are the 2011-2023 precipitation numbers for the two days at DCA: August 12: 2.74 inches total; 2 days with a trace, 4 days with measurable, 1 day with at least an inch, no days with 2+ inches. August 15: 2.37 inches total; 1 day with a trace, 7 days with measurable, 1 day with at least an inch, no days with 2+ inches. This is in contrast to the 1871-2010 precipitation numbers for the two days in DC: August 12: 40.95 inches total; 20 days with a trace, 51 days with measurable, 11 days with at least an inch, 5 days with 2+ inches. August 15: 11.12 inches total; 15 days with a trace, 45 days with measurable, 4 days with at least an inch, no days with 2+ inches.

July 2023 at DCA came in slightly above the 1991-2020 normal, at 81.6 degrees, but that was lower than July 2012 (84.0) and July 2017 (81.7). So, the first seven months of 2023 slipped further behind those two years, with an average temperature of 60.7 degrees, versus 61.8 for the first seven months of 2012 and 60.9 for the first seven months of 2017.

DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA -1.2 -0.2 -0.6 0.4 -0.4 1.6 0.2 1.3 0.4

Despite the intense heat in much of the Northern Hemisphere this summer, DCA has yet to record its first 95-degree or higher day. The last time that failed to occur at DCA by July 21st was 2004, when the hottest temperature recorded all year was just 92.

June 2023 at DCA followed suit with May, averaging only 74.1 degrees -- tied for 76th all-time warmest June in DC history and 2.2 degrees below the 1991-2020 normal. As a result, January-June 2023 dropped further behind 2012, and also fell behind 2017, for the warmest first half of a calendar year in DC. Specifically, the first half of 2023 (181 days) averaged 57.1 degrees at DCA, behind 2012 (182 days) at 58.0 and 2017 (181 days) at 57.3.

DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA -0.4 0.3 0.1 -1.3 -0.2 2.0 1.2 1.5 1.3

DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA -0.3 0.1 -0.5 -0.5 0.0 0.8 -0.4 -2.1 0.7 98 96 95 96 96 102 99 117 92