Pittsburgh PA Area Rest of fall and Winter 2019-2020 thread

[CoraopolisWx]

1 hour ago, Ahoff said:

Groundhog said early Spring.  I feel like we've been in early Spring, extended Fall/Early Spring already, so I guess he's right, lol!

Seems like we've been in a late spring, late Fall pattern going on 4 years now. Wet and muggy summers with warm early winters.

We almost need a dry hot summer to reshuffle the whole pattern.

[Ahoff]

4 hours ago, CoraopolisWx said:

Seems like we've been in a late spring, late Fall pattern going on 4 years now. Wet and muggy summers with warm early winters.

We almost need a dry hot summer to reshuffle the whole pattern.

I'm completely for this, and it eventually has to happen.

Anyway 62 today, gross.

[RitualOfTheTrout]

21 hours ago, CoraopolisWx said:

Would be nice to get a closed off H5 for Friday morning, however at this point it's more of a glorified front.

It's not looking good for much at this point, maybe we get another mushy half inch out of it.

GFS has a little something to watch for Saturday night into Sunday morning.

In other news, with the inch or so of snow over the weekend our seasonal total is now at 12.7  inches, which moves us out of second and into third for least snowfall in recorded history:

1. 1918-1919 8.8in

2. 1889-1890 11.4

3. 2019-2020 12.7

4. 1920-1921 14.4

5. 1931-1932 14.7

6. 1932-1933 15.7

7. 1973-1974 16.6

8. 1990-1991 17.2

9. 1937-1938 18.7

10. 1930-1931 19.0

Also, playing around with the numbers, when the 30 year average jumps from 1981-2010  (41.9) to 1991-2020 (43.5 as of today)  we should see our seasonal snowfall average increase by about an inch an half even if we don't see any more snow this season. It's been a bad year for tracking storms when this is what time typically use for for storm tracking needs to find another outlet lol.

I'm still holding out hope for a fluke storm, or maybe we get something bigger in March. At this point I'd be just as happy to see March torch in the mid 60s all month as I would getting a big storm. I just hope we don't get a raging -AO / -NAO and a cold rainy spring. A slightly moderated continuation of the past 50 days we be awful.

[jwilson]

5 hours ago, RitualOfTheTrout said:

I'm still holding out hope for a fluke storm, or maybe we get something bigger in March. At this point I'd be just as happy to see March torch in the mid 60s all month as I would getting a big storm. I just hope we don't get a raging -AO / -NAO and a cold rainy spring. A slightly moderated continuation of the past 50 days we be awful.

The -NAO through summer is almost a guarantee, at this point.  We've been stuck in this loop where the NAO tanks from April to October and is positive for the winter months.  I imagine that's part of the reason we haven't had a really hot summer in a while.  Then we get the heat into fall (September/October) when the pattern starts flipping.

[jwilson]

Euro and ensembles hint at potential Saturday night along with GFS/Icon.  Canadian doesn't have the shortwave, more of a little northern stream clipper of sorts.

There's a bit of room to come north, which is a good thing, but perhaps the overall pattern hints at another failure in the works.  Retreating high.  Threat has moved around and we're still 4/5 days out.  Hard to get too excited, cap is probably 3" which is relatively small (but would be our biggest hit this winter if materialized).

[Ahoff]

2 hours ago, jwilson said:

The -NAO through summer is almost a guarantee, at this point.  We've been stuck in this loop where the NAO tanks from April to October and is positive for the winter months.  I imagine that's part of the reason we haven't had a really hot summer in a while.  Then we get the heat into fall (September/October) when the pattern starts flipping.

Why is it almost guaranteed?  Is there something that hints at it not changing, except for prior history?

[jwilson]

4 hours ago, Ahoff said:

Why is it almost guaranteed?  Is there something that hints at it not changing, except for prior history?

It's part of a decadal trend, but there's an overall larger trend for the NAO to be positive during the winter months starting back in the 1980s.  The NAO between 1950 and 1980 averaged overwhelmingly negative versus the average since then which has been quite the opposite.

If we break that down a little further, we can see that during the 80s, the NAO spiked upward.  It did begin a downward trend in the 90s which stopped right around 2010 (give or take a couple years), but it still remained positive, overall.  Since then, the NAO has spiked hard positive again.  I think there's an argument the trend should stop soon and start declining again.  Similar to how it operated in the 90s.  That wouldn't necessarily be good news for snow lovers.

Now there's some debate, I suppose, about why this has occurred.  I don't know if data collection and analysis is better now (perhaps the older measurements were flawed or imprecise relative to modern times).  Is it climate change?  Is it short-term variability?  I don't know that anyone is certain on the answer.  I'm not an expert, either.

Here is one relevant portion from a research paper on the NAO and its influence on warming:

Quote

The impact of the summer NAO is much weaker, but still discernible over Europe, North America and Greenland, with the downward trend in the summer NAO from 1988–2012 reducing warming by about a third in Northern Europe and a half in North America.

Basically, the -NAO during summer months has had a negative effect on the warmth of that season over this period.  It has only continued since the time frame included in this particular study.  Not to say a +NAO can't happen during the summer, because it can, but that hasn't been the norm or average in recent history.

Here we can more clearly see the trend of the NAO downward over the summer months (JJA) since the 90s.

There's a bit more from that paper:

Quote

A positive phase of the NAO in winter is associated with . . . [a] weak warming signal [that] can be seen over the United States and cooling over the Mediterranean and Middle East, associated with stronger clockwise flow around the subtropical Atlantic high.  A negative NAO is associated with opposite pressure anomalies, leading to a more wavy jet stream and a weaker, more zonal storm track.

Prior to this decade, of course, the NAO attempted to exert a cooling influence on our winters, but the overall anomalies rose, anyway, in spite of it.  This is due to overall climate change and warming trends outside the influence of the NAO.  Since then, however, the NAO hasn't exerted the same cooling influence on our winters and we've mostly been going the other way.  It helps explain a little why this winter has been basically nonexistant; however, there's a lot of variables to consider.

Quote

From 1920–1971 there was a cooling trend over northern Eurasia and the eastern United States, with warming elsewhere. The NAO downtrend explains the Eurasian cooling, and part of the North American cooling . . . .

Ultimately, the NAO doesn't exert the same influence on summer temps for us as it does for winter temps, so I don't think it's a big reason for our milder summers, but it could still have some impact, especially if the values are strongly anomalous in one direction or the other.

[Rd9108]

Long range NAMs look fantastic too bad it's the NAM. Maybe it can score a coupe.

[MikeB_01]

6 minutes ago, Rd9108 said:

Long range NAMs look fantastic too bad it's the NAM. Maybe it can score a coupe.

Honestly, its a nice trend. We are right on the line, but the 00z GFS showed some hints of bringing the energy back a little further west as well. So the NAM and the GFS are hinting at a slightly stronger LP that runs a little more inland and slower.

Will need to watch, but its a nice to see. Hoping the Canadian comes in with a least a little move

[CoraopolisWx]

9 minutes ago, Rd9108 said:

Long range NAMs look fantastic too bad it's the NAM. Maybe it can score a coupe.

Lol. Yeah. 

But I do imho feel it's NAM or bust. Since our best shot at advisory level snows, would probably be dynamically driven. And the nam does better with dynamic snows. 

[CoraopolisWx]

5 minutes ago, MikeB_01 said:

Honestly, its a nice trend. We are right on the line, but the 00z GFS showed some hints of bringing the energy back a little further west as well. So the NAM and the GFS are hinting at a slightly stronger LP that runs a little more inland and slower.

Will need to watch, but its a nice to see. Hoping the Canadian comes in with a least a little move

Definitely having the other's support would be nice. Gonna be walking that fine line right through Friday morning. 

[MikeB_01]

Canadian made some moves as well... Nothin big, but 2-3 days out, this is a nice trend. I think we would all just some snow falling at this point.

[MAG5035]

I saw NWS Pittsburgh post this graphic the other day and couldn't help but share it in here. I can only hope this century's 20's decade does better for Pittsburgh than the original roaring 20s. In fact, that period from 1919-1935 accounted for 1/3 (11 winters) of the 33 winters since 1880 that started at or less than this season's 12.7" to date. There's a few half decent comebacks in there but that's pretty rough. 

[Ahoff]

7 hours ago, MAG5035 said:

I saw NWS Pittsburgh post this graphic the other day and couldn't help but share it in here. I can only hope this century's 20's decade does better for Pittsburgh than the original roaring 20s. In fact, that period from 1919-1935 accounted for 1/3 (11 winters) of the 33 winters since 1880 that started at or less than this season's 12.7" to date. There's a few half decent comebacks in there but that's pretty rough. 

What this tells me is there have been worse seasons, and they were mostly not recent (30+ years ago).  So, I guess we're in a better period of snow, than in other points in our history.  That's reassuring.

[Burghblizz]

Happy February 5th!

10 years already

[Ahoff]

Accuweather Spring Forecast

Considering the winter forecast was essentially wrong, I have hope this is as well.

What's frustrating is if Spring is delayed, it's a total slap in the face from nature, which really didn't bring in winter in the first place.  Although, to expect chilly weather into March and snow into March isn't really that crazy considering our average for snow is about on par with December, around 8".

[CoraopolisWx]

Euro still likes us for Friday morning, with possible low end advisory amounts. The other guidance is also favorable. 

2-4" is where we'll likely max out, due to the fast flow, and late amplification of the wave.

[Rd9108]

1 minute ago, CoraopolisWx said:

Euro still likes us for Friday morning, with possible low end advisory amounts. The other guidance is also favorable. 

2-4" is where we'll likely max out, due to the fast flow, and late amplification of the wave.

That would be a our biggest storm of the year. I would definitely take that. Maybe we get lucky and it amplifies faster and we somehow get 4-6. 

[RitualOfTheTrout]

37 minutes ago, Rd9108 said:

That would be a our biggest storm of the year. I would definitely take that. Maybe we get lucky and it amplifies faster and we somehow get 4-6. 

It is somewhat refreshing to see something starting to trend better as we get closer in time. I agree, an area wide synoptic 2-4 would be the biggest storm of the year.

In this pattern you take what you can get, but if you look just to the North of us we aren't that far away, it's a shame that boundary couldn't have setup a couple hundred mile further south. Just for a visual, Euro snow map through 240:

[MikeB_01]

SREFS over the last 4 runs --> Trending up.

GEFS Plumes --> 3+ and has been trending up a little over the last few runs.

[jwilson]

It is looking to me like an interior New England special.

GFS & NAM are pretty bearish on this, only a couple inches, at most.  NAM looks oddly dry, actually, until the low gets cranking in the Atlantic.  The Canadian is a bit more bullish, ranging from 3-6" across Allegheny (West to East, respectively).  The Canadian has been better this winter than the GFS so there's a little bit of optimism for you.

We're relying on storm dynamics to bring us snow, requiring decent rates in a fast-moving LP to overcome antecedent warmth.  Not that it can't work, but we might have a period of white rain which limits accumulations.

[Rd9108]

NAM came in hot atleast the 10:1 maps but that heavy precip would come in heavy and drop some impressive rates. Hey maybe we get to atleast see the rates that we have been dying to see. Hours of light/moderate snow just doesnt do it for me as much. That's why I would love to see a repeat 94. The rates in that storm were insane. 

[Mailman]

High res NAM is on steroids.

[Rd9108]

5 minutes ago, Mailman said:

High res NAM is on steroids.

I'm actually intrigued for once. Who knows maybe we get a positive trend for a change. We have been screwed so much that eventually we are due.

[Rd9108]

Actually after looking at the hi rez NAM that's a 913 low. Gonna have to say that's wrong. 

[Rd9108]

Gfs is not our friend. 

[Rd9108]

NAM further NW and jackpots the usual Youngstown area. 

[MikeB_01]

NAM further NW and jackpots the usual Youngstown area. 

Windshield wiper?


.

[jwilson]

Just now, Rd9108 said:

NAM further NW and jackpots the usual Youngstown area. 

Was just about to say the NAM finds a new way to screw us by pulling the low too far west.  It trains the good snow to our west and northwest while dryslotting AGH (and points SE) for a while.  Its totals are overdone, but that general idea is trouble.

[Rd9108]

5 minutes ago, MikeB_01 said:

Windshield wiper?


.

Nope that's us getting excited for 2 runs and then reality smacking us in the face. I'm hoping that it's just the NAM being over amped but man would that suck to miss that way.