mid atlantic leaf thread

[nj2va]

I hope this is a legit post, but does anyone know what effect, if any, this "chilly snap" would have on fall foliage?

Eta: meaning in general, I guess. Does it quicken the peak, shorten it, etc.

[Ian]

I hope this is a legit post, but does anyone know what effect, if any, this "chilly snap" would have on fall foliage?

Eta: meaning in general, I guess. Does it quicken the peak, shorten it, etc.

cool temps help break down the chlorophyll but i think it has more to do with light than anything... the cycle is pretty consistent year to yr. warm temps may help slow/stunt it more than anything i think.

[Bob Chill]

I hope this is a legit post, but does anyone know what effect, if any, this "chilly snap" would have on fall foliage?

Eta: meaning in general, I guess. Does it quicken the peak, shorten it, etc.

Just hope for less wind and rain in Oct. Like Ian said, the cycle is primarily sunlight driven.

Generally speaking, a sunny and dry Oct will bring the best fall colors.

[Kevin Druff]

cool temps help break down the chlorophyll but i think it has more to do with light than anything... the cycle is pretty consistent year to yr. warm temps may help slow/stunt it more than anything i think.

It's my understanding that ideal leaf color conditions are:

1) The trees aren't dying from drought (i.e. a wet summer)

2) Once the time for color changes approaches, you want dry

3) Warm days

4) cool-to-cold nights

[nj2va]

cool temps help break down the chlorophyll but i think it has more to do with light than anything... the cycle is pretty consistent year to yr. warm temps may help slow/stunt it more than anything i think.

Just hope for less wind and rain in Oct. Like Ian said, the cycle is primarily sunlight driven.

Generally speaking, a sunny and dry Oct will bring the best fall colors.

It's my understanding that ideal leaf color conditions are:

1) The trees aren't dying from drought (i.e. a wet summer)

2) Once the time for color changes approaches, you want dry

3) Warm days

4) cool-to-cold nights

Thanks for the replies - I do remember reading somewhere that a drought is bad for color so all that rain we had should help...just don't need a repeat next month. Best part about fall (besides the mild temps during the day and chilly nights) is the foliage!

[Rib]

Models obviously underdoing the cold air. The light qpf could mean flurries.

[Bob Chill]

Models obviously underdoing the cold air. The light qpf could mean flurries.

Eh, sun angle and time of day is going to be a problem. It might stick to grassy surfaces but no way on the streets.

[jonjon]

It's my understanding that ideal leaf color conditions are:

1) The trees aren't dying from drought (i.e. a wet summer)

2) Once the time for color changes approaches, you want dry

3) Warm days

4) cool-to-cold nights

This sums up my understanding of optimal foliage conditions as well. I'd like to add that I understand that while cold nights help, its best to keep temps above freezing -- a freeze or frost may encourage early drop.

The leaves are changing rapidly up here now (hope so as our Leaf Peepers Festival is next weekend) -- I hope we don't get too cold over the next couple of nights.

[WinterWxLuvr]

This sums up my understanding of optimal foliage conditions as well. I'd like to add that I understand that while cold nights help, its best to keep temps above freezing -- a freeze or frost may encourage early drop.

The leaves are changing rapidly up here now (hope so as our Leaf Peepers Festival is next weekend) -- I hope we don't get too cold over the next couple of nights.

I've heard that one myself.

I agree with everyone here that the change is sunlight (or lack thereof) driven. In fact, I've always thought the process starts much earlier than we think, it's just that we can't notice it at first. Once the process starts, it's the condition of the leaf itself that would determine the quality of the color. I think the recent rains will help. We need it dry at peak time though. Rain would also help in the early drop of the leaves.

[jonjon]

I'm convinced that temps play almost an equal role as sunlight. After all, our trees up here are subject to the same sun angle as most reading this thread -- but our leaves change a month or more earlier. Temps have to be playing a very substantial role.

[TalcottWx]

When do the leaves usually change in Baltimore?

[WinterWxLuvr]

I'm convinced that temps play almost an equal role as sunlight. After all, our trees up here are subject to the same sun angle as most reading this thread -- but our leaves change a month or more earlier. Temps have to be playing a very substantial role.

I don't think I agree with this. I think temps have a day or two or three role, but I think in your case it is the elevation. Not the temps because of elevation, but differences in the types of trees that grow there and in the differences that the leaves are exposed to as far as the air (or lack of) around them. Less oxygen, less carbon dioxide, less air period, has to play some role.

If temps played that big of a role, you'd have wild swings wrt to the peak of the season just because of an abnormally warm or cold fall. Look at it this way. It stays warm in southern Ga or northern Fla for a long time. If you plant a sugar maple in Jacksonville, it will still change color. It will do it later, because of sun angle and the fact that it will be at sea level, but it will still change. In fact, if you put their average temps beside their sun angle, I'll bet leaves there would change at a much warmer temp (when compared to sun angle, say, in Davis).

[Bob Chill]

Good read for the layman: http://www.na.fs.fed.us/fhp/pubs/leaves/leaves.shtm

Makes complete sense to me.

[jonjon]

I don't think I agree with this. I think temps have a day or two or three role, but I think in your case it is the elevation. Not the temps because of elevation, but differences in the types of trees that grow there and in the differences that the leaves are exposed to as far as the air (or lack of) around them. Less oxygen, less carbon dioxide, less air period, has to play some role.

If temps played that big of a role, you'd have wild swings wrt to the peak of the season just because of an abnormally warm or cold fall. Look at it this way. It stays warm in southern Ga or northern Fla for a long time. If you plant a sugar maple in Jacksonville, it will still change color. It will do it later, because of sun angle and the fact that it will be at sea level, but it will still change. In fact, if you put their average temps beside their sun angle, I'll bet leaves there would change at a much warmer temp (when compared to sun angle, say, in Davis).

I've never heard of elevation in itself as being a factor (i.e. oxygen, etc.) -- it always seems to be sunlight (which never changes), temperature, and moisture. I've seen relatively wild swings as to peak foliage here -- from as early as the last week of Sept. to as late as mid Oct. -- and the early peaks were during cold falls and the late were during warm falls. I attribute the difference in peaks between our areas as mostly being temperature related -- but I'm game for learning something new.

[TradeWinds]

When do the leaves usually change in Baltimore?

I've found that Central Maryland often hits peak around Halloween sometimes into the first week of November. The Shenandoah is about the 2nd week of October and always worth a trip out there. The problem I always see around here are the maples give the best color but the leaves fall before some of the tulip trees, oaks, and pear trees hit peak do so the timing is off a little. I always use this site to track the foliage....http://www.foliagenetwork.com/.

[Bob Chill]

Temperature plays a minor role in when the leaves change. Elevation certainly seems to play a big role though. The peak in the NC mountains happens well before us here on the piedmont or coastal plain. That is way south in latitude too. Can't just be termperature. There has to be more to it.

Since sunlight is the primary driver of the change due to chlorophyll breakdown, then one could speculate that topographical influence on the amount of direct sunlight might be a driving force for leaves to change earlier in the mountains at the same latitude of lower elevations that change much later.

Maybe jonjon can help up with his obs. If what I'm thinking is right, the shade caused by the mountains themselves impacts when the leaves change. Direct sunlight is cut short quite a bit by having ridges to the east and west. If my theory is correct then N facing slopes would be the first to start changing in the mountains. It would also make sense that the valleys between high ridges would change before valley between low ridges.

I don't know if my theory has any credence but it sounds good to me.

[jonjon]

Temperature plays a minor role in when the leaves change. Elevation certainly seems to play a big role though. The peak in the NC mountains happens well before us here on the piedmont or coastal plain. That is way south in latitude too. Can't just be termperature. There has to be more to it.

Since sunlight is the primary driver of the change due to chlorophyll breakdown, then one could speculate that topographical influence on the amount of direct sunlight might be a driving force for leaves to change earlier in the mountains at the same latitude of lower elevations that change much later.

Maybe jonjon can help up with his obs. If what I'm thinking is right, the shade caused by the mountains themselves impacts when the leaves change. Direct sunlight is cut short quite a bit by having ridges to the east and west. If my theory is correct then N facing slopes would be the first to start changing in the mountains. It would also make sense that the valleys between high ridges would change before valley between low ridges.

I don't know if my theory has any credence but it sounds good to me.

I know the north side of Canaan Mountain (which we can see from our house) has more brilliant colors and turns slightly earlier than the other trees around here -- so you may have some credibility to your theory.

I think that the only reason elevation plays a role is because of temperatures, not the elevation itself. The higher elevations of the NC mountains are colder, therefore the earlier change than the piedmont or coastal plain.

[BethesdaWX]

I know the north side of Canaan Mountain (which we can see from our house) has more brilliant colors and turns slightly earlier than the other trees around here -- so you may have some credibility to your theory.

I think that the only reason elevation plays a role is because of temperatures, not the elevation itself. The higher elevations of the NC mountains are colder, therefore the earlier change than the piedmont or coastal plain.

I agree with you, temperature does play a role too, warmer septembers/octobers usually lead to a later peak down this way from what I've noticed. Your temperature is a full 10-15 degrees cooler in the fall I would think, obviously that will have an effect.

Though you also probably have more cloud cover up there too in fall, upslope, etc.

[BethesdaWX]

While outside today, for the first time I really felt like it was Fall. And it looked like it. A cool breeze with leaves falling off the trees and blowing across the street.

Winter is close!! haha

Yeah trees are really dropping leaves early, awoke to my yard blanketed in leaves, most from my nieghbors yard as usual lol

[nj2va]

I've found that Central Maryland often hits peak around Halloween sometimes into the first week of November. The Shenandoah is about the 2nd week of October and always worth a trip out there. The problem I always see around here are the maples give the best color but the leaves fall before some of the tulip trees, oaks, and pear trees hit peak do so the timing is off a little. I always use this site to track the foliage....http://www.foliagenetwork.com/.

Yeah, I noticed that last year as well. Best foliage I have seen was in VT/NH. The Poconos have good foliage too. Thanks for that website...it's showing the NE with no color thus far - should really be filling in over the next 2 weeks.

[WinterWxLuvr]

I've never heard of elevation in itself as being a factor (i.e. oxygen, etc.) -- it always seems to be sunlight (which never changes), temperature, and moisture. I've seen relatively wild swings as to peak foliage here -- from as early as the last week of Sept. to as late as mid Oct. -- and the early peaks were during cold falls and the late were during warm falls. I attribute the difference in peaks between our areas as mostly being temperature related -- but I'm game for learning something new.

Well, I don't proclaim to be an expert on this, but I'll give you another example. Let's take the Smoky Mountains for example. The trees at say 5000 feet elevation and up will all be stunted and small (or at least smaller and getting progressively smaller). Well, the temperatures at 5000 feet in the Smoky Mountains aren't harsh by any means. They probably, on average, would be close to the average temps in, say central to northern Pa. Now, in central and northern Pa, you'll find the same trees that you find in the Smokies at 5000 feet, but they will be full size, not stunted and small. If they average the same temps, why would the trees grow differently in the Smokies? It has to be the elevation and the thinner air. IMO, the same forces at play there are at play in causing the earlier leaf color at your elevation.

[Kevin Druff]

http://tinyurl.com/3z4kq2z

Temperature plays a minor role in when the leaves change. Elevation certainly seems to play a big role though. The peak in the NC mountains happens well before us here on the piedmont or coastal plain. That is way south in latitude too. Can't just be termperature. There has to be more to it.

Since sunlight is the primary driver of the change due to chlorophyll breakdown, then one could speculate that topographical influence on the amount of direct sunlight might be a driving force for leaves to change earlier in the mountains at the same latitude of lower elevations that change much later.

Maybe jonjon can help up with his obs. If what I'm thinking is right, the shade caused by the mountains themselves impacts when the leaves change. Direct sunlight is cut short quite a bit by having ridges to the east and west. If my theory is correct then N facing slopes would be the first to start changing in the mountains. It would also make sense that the valleys between high ridges would change before valley between low ridges.

I don't know if my theory has any credence but it sounds good to me.

[BethesdaWX]

Well, I don't proclaim to be an expert on this, but I'll give you another example. Let's take the Smoky Mountains for example. The trees at say 5000 feet elevation and up will all be stunted and small (or at least smaller and getting progressively smaller). Well, the temperatures at 5000 feet in the Smoky Mountains aren't harsh by any means. They probably, on average, would be close to the average tem

ps in, say central to northern Pa. Now, in central and northern Pa, you'll find the same trees that you find in the Smokies at 5000 feet, but they will be full size, not stunted and small. If they average the same temps, why would the trees grow differently in the Smokies? It has to be the elevation and the thinner air. IMO, the same forces at play

there are at play in causing the earlier leaf color at your elevation.

Not sure about that, I have a bro who lives in Garrett county 3000ft up, and there are plenty of large trees up at that elevation, in fact some are close to 100ft. It might be soil stunting growth, could be more clouds, but oxygen isn't the cuprit I don't think.

And still the trees change color sooner by almost 4 weeks out in Garrett county.

[SoCoWx]

We're starting to see some minor, but healthy change here in SE Va.

[jonjon]

Well, I don't proclaim to be an expert on this, but I'll give you another example. Let's take the Smoky Mountains for example. The trees at say 5000 feet elevation and up will all be stunted and small (or at least smaller and getting progressively smaller). Well, the temperatures at 5000 feet in the Smoky Mountains aren't harsh by any means. They probably, on average, would be close to the average temps in, say central to northern Pa. Now, in central and northern Pa, you'll find the same trees that you find in the Smokies at 5000 feet, but they will be full size, not stunted and small. If they average the same temps, why would the trees grow differently in the Smokies? It has to be the elevation and the thinner air. IMO, the same forces at play there are at play in causing the earlier leaf color at your elevation.

Tree growth has a lot more to do with growing conditions -- such as soil depth and quality. When you get up to the highest elevations there often are issues with soil depth and quality (you can see that around here at Dolly Sods) and also very harsh weather conditions such as wind, fog and rime ice. But large, healthy trees grow at high elevations in many areas. Canaan Valley was once a magnificent virgin forest, although it is the highest valley east of the Mississippi. Davis was a booming lumber town at one time because of this. I also think that the climate above 5,000 feet in Tennessee is colder than it is in northern PA. Its probably similar to what it is here at 3,000 feet in WV -- and our leaves change before the lower elevations of New England.

[BethesdaWX]

Not sure if the summer drought is causing early leaf drop but I can't remember it coming so soon, some trees have already lost maybe 40% of their leaves.

Took some pictures yesteday.

Sunrise yesterday morning on my way to a trimming job, Can see Some of the Trees near the rising sun have lost Most of their leaves already.

Quick pics.

Some people still haven't fixed their antennas after Hurricane Irene, one of many houses with lazy folk.

[WxUSAF]

Maybe it was the hurricane-force wind gusts from Irene that knocked down all those leaves in Bethesda?

[Bob Chill]

Some people still haven't fixed their antennas after Hurricane Irene, one of many houses with lazy folk.

Lazy because they haven't fixed it in the last couple of weeks or lazy because they haven't removed something that hasn't been needed in a couple of decades?

[BethesdaWX]

Lazy because they haven't fixed it in the last couple of weeks or lazy because they haven't removed something that hasn't been needed in a couple of decades?

Both, # 2 especially, those who keep them standing have already recieved complaints from some of the nuttier folks.

Lucky to live in an area where there are no community restrictions, but the same problems exist.

[BethesdaWX]

Maybe it was the hurricane-force wind gusts from Irene that knocked down all those leaves in Bethesda?

Yeah had some gusts in the 90mph range last night, so that was probably the culprit