Cobalt

August 1st through December 21st has averaged 60.7°F at DCA, the coldest for that stretch since the year 2000 (58.4°F), and 1.5°F below the 30 year average.

BWI has just recorded its 10th coldest 1st half of December, with an average temperature of 31.4F. DCA comes in at 19th coldest (34.4F) Just as compelling are the stats for max daytime temperatures so far this month. BWI's mark of 45F ties with 1904 for the lowest high temperature seen in the first half of December. DCA 2nd lowest (46F). As for the upcoming warmup.. DCA's 30 year average max temperature for the 2nd half of December is 64F, so what might feel like a Holidays "torch" is actually not too uncommon.

looks better than 12z from this angle

12 days into the month (today's stats are yet to be added), DCA has seen 9 days feature subfreezing temperatures. That beats the entirety of Decembers 2023, 2021, 2018, 2015, 2014, 2012, and 2011. By the start of the mid-month warmup DCA will be tied with last December at 13. Still a decent chance that the airport tops 2022 for most subfreezing lows in December since 2010 (Towering above most years at 27 days)

was checking area temps ahead of this system and.. whose station is this??

sure, why not.

I think he's interpreting it as NW just due to the perspective from his locale, but yeah precip on the whole took a 25+ mile jump due West from 6z. Maybe a slight North lean but more West than anything. Pretty happy that I'm back in McLean for the holidays for this one

Hi! Was wondering where you went, since it seems like you, qg_omega, and co go mia every time there's a snow or cold threat. Speaking of which, hope you enjoy the snow tomorrow. Seems like you and areas to your south near NYC are game for an appreciable December snowfall.

You know who

Sounds like a bit of gambler's fallacy also.

2F off of the record set in 1989, impressive.

Still waiting for your very warm post-Thanksgiving pattern to start showing up..

This is almost certainly survivorship bias. Few here might remember the string of runs from the Euro and GFS and their ensemble counterparts from the week before that, showing a massive overrunning event that fizzled out at medium range.

Snow was sparse, but those winters were on average much colder than than the below average snowfall winters of recent. A colder/dryer look versus the warmer that we've become accustomed to. The warmest winter in all of the 80s for the Northeast would've been the 4th coldest of the past 10 years.

The United States is just a small part of the northern hemisphere's cryosphere. Overall, NHem snow cover is still at a record low for the date. This is in large part due to that huge deficiency in Eastern Eurasia, some 3x the surplus in the US. Eurasian snowcover growth is at a standstill.

That's a first.. a modeled underperformer

26F with light snow in Harrisonburg. Coating to an inch on most surfaces, and starting to accumulate on the parking lot pavement. Going for a walk when a batch of moderate snow moves through in a bit.

This is a true sentiment. I guess what I was getting at was that 24/25 of the past Decembers have been in that second camp, some bolstered by the fact that they do not need to be as cold as December 2017 to see prolific winter conditions. I agree with you on the last part. Cold and snowy times are already an infrequent part of an infrequent season. We deserve to enjoy the times where winter shows its true hand.

They run off of 30 year normals. Most sites run off of 1991-2020 averages, which were a step up from 1981-2010 averages, which were a step up from 1971-2000 averages. Im surprised nobody's made a tool to show what specific months or years would look like using modern 30 year averages vs older ones.

I took a look at the normals. Northeast Decembers as cold as the coldest one of the 21st century (Dec 2017, 24.2F) used to occur an average of 1 every 2.83 years from 1895-2000.

1.6" at DCA would be the snowiest December event for the airport in 16 years. Guidance says to take the under but certainly not off the table.

I recall the Feb 16-17 2015 event being sold as a 6-10"+ event solely because of it was progged to have 0.3-0.5" of precip fall in a brutally cold airmass. That was around when kuchera was beginning to get attention, but come game time the snow growth was terrible and grainy, and ratios were much closer to 10:1.

6z Euro tops out at 28F for the 5th at DCA. Almanac data says the daily record low max is 25F from 1886. A day later and it would be threatening that record low max of 29F (1910).

Past two runs have had increasing separation between the southern and northern waves. That looks like an ample route to a success scenario.