psuhoffman

It's a legit threat. Not all longwave patterns are created equal. Not all -PNA's are created equal. A -PNA pattern without any blocking and a scorched N America with no cold air anywhere is never going to work, and that is what we've had when we've had a -PNA most of the time lately. A -PNA with blocking and a N America covered in snow and cold air left over could possibly work. Yes it will be a warmer pattern, yea any wave COULD end up rain...but at least there will be waves coming at us and room for them to amplify.

@Chris78 @CAPE we did need the pattern to relax some... the amount of blocking we had along with the +PNA -EPO was causing extreme suppression. The one significant precipitation event we've had in the last month came during a temporary -PNA. And this is not uncommon. I've said before that when I looked at every single 5"+ Baltimore snowstorm the majority of them did not come in frigid arctic regimes. And it becomes even more apparent if you just look at the 10"+ storms. There are several reasons for this. Big storms ride the thermal boundary and that means they are usually along the rain/snow line...not in the middle of an arctic airmass! We have to be somewhat near the warmth to win OR there has to be a wave amplifying enough to press the warm boundary back towards us! Waves don't amplify in a cold NW flow regime! There are some rare examples of super cold storms, we got one last week, but it requires so many rare things to time up perfectly...if that is the only way we get big snowstorms we would be in big big trouble. A lot of our big snowstorms came during periods that weren't that cold. Feb 83, Feb 87, Jan 2000, Feb 2006, Feb 2010, Jan 2011, Feb 2014, March 2015, Jan 2016 all came during periods that weren't arctic cold right around the time of the storm and most of them we even had to worry if it would even be cold enough! Way way way more of our big snowstorms come during "just cold enough" regimes not during our craziest coldest arctic airmasses. Those tend to be dry. We can luck our way into a frontal wave or weaker snow...smaller snowstorms are more common in these cold periods...and we've been perhaps unlucky not to get at least some of those during this latest period...but our true big snowstorms usually come during less cold periods. What's been especially frustrating over the last 10 years is a lot of the patterns that historically would provide us with chances of snowstorms...not cold but should be "just cold enough with a good track" ended up just too warm and when a perfect track system came alone it ended up a perfect track rainstorm. But that doesn't change the equation. It's been so long since we had a big region wide snowstorm during a pattern like Feb 2006 or Feb 2010 that it seems some are starting to think we need some big EPO/PNA ridge induced arctic airmass to get a big snowstorm but that's never been our typical path to a big snow. Most of our big snowstorms came during blocking regimes with a split flow under it and no arctic air anywhere (no NS to FCK up the flow) and some juiced up STJ wave came along with the perfect track and it was just barely cold enough to snow.

we had a blizzard what would have been presidents weekend 1958 but the holiday was still called Washington’s Birthday then.

If you think the lack of a blockbuster rare huge snowstorm Feb 20-28 is not just the product of a random chance distribution of a rare event over a limited sample then explain the causation. Finding some pattern in numbers means absolutely nothing if you can’t show there is causality and it’s not just an artifact or randomness.

Persistence works more than 50% but it’s not enough to just rely on it. just off my head these winters featured significant pattern shifts and storm track changes 1993, 1999, 2000, 2004, 2005, 2006, 2007, 2015, 2016, 2018, 2019, 2022

Where the warmest anomalies are changes exactly how the pattern sets up. A more west based Nino places the tropical forcing closer to the dateline which is where we want it. That tends to correlate with a trough southwest of Alaska...the downstream impacts of which are good for us. An east based nino shifts the whole pattern further east and often we see the north pacific trough end up too close to the Pacific NW which floods the CONUS with pac puke. We need that to be pulled back some.

Sometimes a QPF pattern persists all season...sometimes not. Remember 2015, Everyone thought we were toast when all those snows hit north of us through January and early Feb...then it became our turn from Feb 15 into March. That was maybe the most extreme example but it's hit or miss whether the a pattern persists the whole cold season...the problem with using persistence is it works until it doesn't and it's hard to predict when the pattern is going to change until it does.

The latest CANSIPS was indicating a possible modoki nino. That would increase our chances significantly.

It's true that we will lose the deep constant cold and enter a more variable period...but so long as we have blocking in February or March there is the threat of a snowstorm.

can we really call it a jackpot?

The humidity might rise slightly for a time.

Tracking clouds

So much here…We almost get a snowstorm 48 hours after this. On aigfs we do. And it’s the long range gfs.

There are some similarities to 2018 only in this case the TPV was weaker to begin with and the warming is happening about a week earlier. Obviously we will need luck to go our way...but if we got a similar pattern to March 2018 and got it to set in 7-10 days earlier AND with a colder N American profile to start... I would roll the dice with that.

Might take the kids to snowshoe

90% of our winters end in disappointment. March snow has nothing to do with it.

PD is a different date each year. Baltimore had a top 20 snow on Feb 19th. That’s layer than PD 90% of the time. So now we’re just talking 8 days? Yes there hasn’t been a too 20 event from Feb 20-28. But there have been big snows after that. It’s a fluke. If anything it means we’re due to get a storm that week! There are so many weeks without a top 20 snowstorm. They are so rare and some weeks have 3 of them meaning there are many weeks with none. The last week of December. The first week of January. January 9-21 have none! Why don’t you obsess about those? you do this with lots of things. You seem to try to assign meaning to randomness. The fact a super rare event hasn’t happened in the 140 years of records that one week is just a product of random chance. There are several other weeks without a big snow and I promise you if we had records that went back far enough you’d see that storms can happen those weeks and this is just random chance over a limited period of time.

A March 2018 is possible. If we could start the cycle a week earlier and get a little more luck in our area could be good. That month was so so so close to epic and we got about as unlucky as possible to only get one decent snow that month.

3 of Baltimores 17 biggest snowstorms came in March. Baltimore has had snows of 22”, 16” and 13” in March. And 2 years ago I ran the numbers and showed that Baltimores odds of getting a 4”, 8” and 12” Storm peak the first week of February but then only decrease slightly until you get to the 3rd week of March when they drop off a cliff. You say this every year. Every single year. And one proven it’s false like 3 times and you still say it. Why?

You give him an inch…

It’s gonna be the worst inch ever!

I hear you. But the last 2 ninos did you no good. My only point was assuming a Nino fixes this seems flawed. The issue hasn’t been enso.

That would depend on other factors. AO being the most important. Type of Nino. If we get a +AO east based +QBO winter we might be looking at a 1992 1995 type disaster but it’s too soon to know that yet. I’m not predicting doom and gloom. We have Chuck for that. I’m just saying don’t assume the rest of this winter is going to suck and don’t assume next year will be good.

But jokes aside why are you attributing our issues with enso. During the recent snow drought we’ve had 4 Nina’s. 3 neutrals and 2 ninos. And the snow results have been equally atrocious across them all for the most part. Arguably the closest we came to a good winter was 2021 which was a Nina but it was slightly too warm in DC. I got 50” here while 95 was getting 36 degree perfect track rainstorms all winter. But the issue wasn’t dry that winter! I don’t think enso had been our issue. Yes overall ninos are better and give us the best chance of a blockbuster winter. But it’s not as simple as Nino good everything else suck. We can have bad ninos and snowy Nina’s. The record -PDO the last 7 years was the bigger issue not enso.

It wasn’t the best period (unfavorable NAO and PDO combo) but not as bad as recent run! 1988 was solid. 1990 great first 1/3. 1993 and 1994 were really nice winters not far NW of 95. 96 of course then Jan 2000. It wasn’t quite the sustained dreg of the recent stretch. But ya far from glory days.