A Better Weather Forecast

Thanks to an Environmental Grant several years ago, the Landscape department has been running a personal weather station down at the track off of Porter Field Road, with a second more recent station up at Breadloaf campus. We depend on these stations for primarily for snow removal and IPM strategies. The data are also streamed to the Weather Underground, a weather web site that accumulates and posts data for over 10,000 stations across the US.

Any compulsive weather addicts know how tricky it is to forecast weather for a region-most people say the forecasters are “wrong”. A better interpretation would probably be to say they aren’t accurate, and Vermont is a great example of why. The National Weather Service has various offices, and ours is in Burlington at the airport. They cover a large area, from Lake Placid to Montpelier, and from the Canadian Border to Killington. The only way to accurately forecast an area this large is to break it into regions. For example, our region is number 9, Western Addison, including the cities of Vergennes and Middlebury. And here lies the problem with forecasting, particularly in the winter. Middlebury campus is under the same forecast as Lake Champlain, and Vergennes shares the forecast with Brandon. It’s a huge geographical area, and one forecast for such a space is bound to lose accuracy across the region. Addison may get an 1″ of snow, low in the valley, while East Middlebury may be getting hammered with 6 times that, under the same forecast.

The Weather Underground has been taking the National Weather Service forecast, and re-packaging it on their website, along with access to some great radar maps, blogs, photos, etc. Recently, however, they’ve starting forecasting themselves, called Best Forecast, and what makes this different is the data, not only from all of the NWS weather stations, but all of the personal weather stations such as ours. Slate just wrote a great article explaining this. Suffice it to say that Best Forecast is now taking into account microclimates, so when pulling up a Middlebury forecast on the WU, we are getting a Middlebury campus forecast.

How accurate? We’ll find out tonight and tomorrow. The NWS is forecasting a dusting to 2″ of snow tonight, with an additional 3-5″ possible tomorrow before it changes to rain. Temperatures mid 20’s tonight, mid 30’s tomorrow. Best Forecast? Lows of 28 tonight, 50% chance of snow or rain, high of 45 tomorrow, snow than rain in the afternoon, snow accumulations of 1″ possible. I’m not placing bets on who is correct here, but the Best Forecast feels right to me. I’ll post an update when all is said and done.

UPDATE 4PM: The NWS issues forecasts at fairly regular times, 3 PM or so being fairly regular. Their update for the western addison zone has changed slightly, 2-4″ during the day tomorrow, changing to rain in the afternoon, back to snow Friday night with an additional 1-3″. Mid 30’s tomorrow, mid 20’s tomorrow night. Best Forecast has changed little-snow and rain tomorrow, accumulation 1″, chance of ice pellets, snow and rain friday night, only 60% chance, no accumulation mentioned.

UPDATE 12 NOON FRIDAY: The NWS has changed their forecast, as the storm seems to have slowed down from the west. No snow last night, and only light snow now at noon, not accumulating. So do we call this a win for Best Forecast? Both forecasts now are in line with each other for snowfall tonight, 4-6″, but Best Forecast is calling for temps today around 45, with the NWS saying mid 30’s, which it is now. I’d be surprised if temps rise today.

A Wednesday Thunderstorm

Last wednesday we had a rip-banger. Thunderstorms developed in the hot summer air over Northern New York, and built as they tracked across the lake. The line continued to build once across the lake, and erupted on top of Middlebury.

I was sitting at home, (I was at work early), watching lightening strike all around us, many up on the ridge of Snake Mountain, some in the fields below. The wind was howling, and sheets of rain poured down. The Middlebury weather station recorded a 20 degree temperature drop in less than a half of an hour, and more than a half an inch of rain in the same amount of time. Peak wind gust came in at 40 mph.

The college weathered the storm ok, but 3 trees took it quite hard. A Green Ash behind Emma Willard (Admissions) took a lightning strike-that was interesting, as it was the shortest tree around, but it was all by itself in the center of the back yard.

Another tree we lost, not surprising, but still sad, was a large Weeping Willow on the northwest side of Battell Beach (the upper Quidditch Pitch). We almost always see Adirondack chairs underneath this tree. The center two stems of this tree had a fast moving fungus that caused a rot in the sapwood of the two center trunks. The sapwood is what carries water upwards to the branches, as well as nutrients throughout the tree, so having this vital structure rot away was a irrecoverable death in waiting. High winds torqued one of the trunks, and broke it away to lean against one of the remaining ones. We removed the tree the next day, before it broke further on someone sitting in a chair.

The final tree may or may not be a casualty, time will tell. One of the large Norway spruces we left in the Main Quad Tree Removal, the most southern one, was hit by lightning. Friends at work in the service building told me it was the most impressive lightning strike they’d heard in a long time. The tree shows a classic spiral scar from the top of the tree all the way down to the bottom root flare. Bark like shrapnel was scattered all over the quad in long 3′ strips, and filled the back of one of our gators. The prognosis of the tree is unknown. The roots seem to be intact-while there is bark peeling on the root flare, it does not seem too bad. Certainly I’ve seen trees recover from worse. We’ll know in a couple of weeks-if the tree is going to die quickly we’ll know soon.

Another Day, another storm

The storms certainly keep coming, and, worryingly, the trees keep succumbing.  Today at 3:30 a very brief but intense cell blasted through campus. We’d lost power for a little bit, I don’t know why. The weather station recorded about 1/4″ of rain in 15 minutes, with a peak wind gust of 35 mph, from the north. This was enough to take the life of a poor Hackberry tree.

Hackberry by Warner Science

This poor tree had been scarred at the base years ago, maybe by a random mouse, maybe by something mechanical. At any rate, the worst place to wound a tree is right at the base. A tree has a very hard time compartmentalizing the wound at the base, and structural integrity of both trunk and root system is compromised. Look at the picture below-the wound was on the north side of the tree. The roots rotted away on that side, and the strong north wind gust toppled the tree right over.

Base of Hackberry

I took these pictures on my way home at 4, but I would imagine the rest of the campus trees are fine. A perfect wind knocked this one down. I’ve already got a replacement in mind.

EDIT: Middblog just posted some YouTube video of the rain here-it’s impressive.

Continued Drought, and some hope

The drought continues here on campus, and in the broader Champlain Valley. Our last rainfall was .4″, and after transplanting a tree afterword I saw the ground had only gotten moist about 1″ down-powder dry soil beneath.

I forget where I found them (probably Lifehacker), but some recent pictures of the US taken by the Gravity Recovery and Climate Experiment satellites show in stark maps the bubble of drought we seem to find ourselves in right now. The first map shows soil surface moisture, moisture in the first centimeter of soil. Look for the little dark red blob right on top of Middlebury. (click on maps for larger view)

soilmoisture_gra_2015257_sfsm_lrg

The next shows root zone soil moisture, the top meter (39″) of soil.

soilmoisture_gra_2015257_rtzsm_lrg

This final map shows ground water in shallow aquifers (like the well at my house!).

soilmoisture_gra_2015257_gws_lrg

I’ll include the overall map of all three maps, which give a legend to the colors. The explanation is as follows (and is quite scary!)-“The maps do not show an absolute measure of wetness, or water content. Instead they show how water content in mid-September 2015 compares to the average for the same time of year between 1948 and 2012. Dark red represents areas where dry conditions have reached levels that historically occur less than 2 percent of the time (once every 50 or more years).” Note how we are in the dark red in all three maps.
soilmoisture_gra_20150914

If you have a little bit of time, by all means read how gravity sensing satellites can figure out how much water is in the earth. In a nutshell, it’s two satellites seperated by 139 miles, and sensing how much they move towards or away from each other as they orbit minute changes in gravity from earth can be measured. The complete explaination is at http://earthobservatory.nasa.gov/Features/GRACE/ .

Hope is on the way, though. We’re looking at a pattern change, with a cold front moving into the area and drawing moisture into the region, possibly an inch of rain or more. That’s a good start. Here’s a good rundown from the Northeast River Forecast Center.

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Cut Off Low

All professions seem to have their own language, most of it inscrutable. What’s impressed me about meteorology is their ability to take seemingly innocuous plain words and string them together in ways to make them terribly confusing. While doing a little digging to figure out just what’s been going on with the weather these last couple of weeks I came across the phrase “cut-off low”.

Apparently all of our moist, tropical air we’ve been (not really) enjoying is thanks to the jet stream, which has made up its mind this year to take an exceptionally strange dip southward across the plains. This leaves a path for the heat and moisture to stream northward into New England. A Weather Underground map from yesterday shows it pretty well.

2xus_jt

Not only is the dip odd, but the fact that the jet stream is staying like this for several weeks is striking forecasters as peculiar as well. This is setting us up for what we’ve seen for the last week or two, hot muggy days with the ability to build thunderstorms, the late summer tropical kind with torrential rain only fun to play in when you’re young.

Working, not so much.

Last night’s storm, however, was a cut-off low. Cut off, it seems, from the jet stream. While it should have missed us altogether, instead it meandered up north and east, dumping an impressive amount of rain in northern New York (the forecast called for it to be over us, but it stayed a little to the west).

2xus_sf

Now it is going to poke around Quebec for a while, probably exiting out the Saint Lawrence seaway at some point, once it gets caught back up again in the jet stream. The dip is forecast to be around for a while, so the rest of the week we’re looking at more warm, muggy, tropical August weather. We got .75″ of rain last night, bringing June up to 5.47″ of rain. Last year June had 2.3″ of rain, two years ago 3.1″. That’s why my boots aren’t drying out anytime soon.

Drought Stress

Our barely green lawns across campus belie a hard fact this summer-it’s been dry. Very, very dry.

Funny, considering how wet it was in late spring, when it was almost too wet to do anything outside. The High Plains Regional Climate Center (kick ass website for weather geeks!) maps show we have 25% of the normal precipitation in the last two months, that’s a 6″ deficit of rainfall.

60dPNormNRCC60dPDeptNRCC

A general rule of thumb I can’t find a reference for but I always tell anyone is that Vermont plants need a 1/2″ of rainfall per week for optimum growth. We’ve had only about 1″ in all of August, and only 1″ in July. Most of that falling in one day, leaving our clay soils to dry out and become nearly resistant to small rainfalls.

The early leaves you see falling are signs of that. Trees in temperature zones such as ours develop wide, spreading root systems, not going too deep in search of water or nutrients. In fact, much of our campus is on ledge, with very little topsoil available, meaning plants need to go shallow and wide to root into the ground.

(My unsubstantiated theory is that Middlebury was founded where it is because of the ledge-poor soils make poor farmland, and why waste valuable agricultural soils and farmland on something as unimportant as a college? Farmland in 1825 was precious, hard earned space, so let the geeks have the hill, we’ve got crops to harvest)

These wide spreading root systems enable fast, efficient uptake of water and nutrients in poor soils and a short growing season. In ordinary years, this is ideal, but in dry years, this strategy can be costly. As you can imagine, the shallow soils dry quickly, and the plants don’t have the deep extensive root systems to find moisture in the lower soil profiles. Trees are gamblers, and they’ve got a losing hand this year.

Older Black maple in the Library quad showing drought stess in the upper canopy.
Older Black maple in the Library quad showing drought stess in the upper canopy.

Flowers and other perennials show stress by wilting-the curling of the leaves cut down on the loss of water through the stomata (transpiration, if you want to flash back to high school biology). Trees react like that too, but also have the ability to shed leaves. We are seeing this now, and it may cause an early fall. The inner leaves on trees turn color and fall away, a survival mechanism. Inner leaves in the crown are not as efficient, they don’t photosynthesize as well, and therefore are not as “useful” to the tree as the outer, younger leaves. In desperation, the tree will shed the inefficient leaves ,brutally choosing the younger leaves to use the precious remaining water they have remaining.

Younger Red maple showing classic drought stress-note interior leaves browning with ends of branches still green
Younger Red maple showing classic drought stress-note interior leaves browning with ends of branches still green
Closeup of foliage
Closeup of foliage

We’ve had a little bit of rain this weekend, and more is coming, so luck it will come in time to prevent a wholesale dropping of leaves before your parents come up for fall family weekend. Snake Mountain above my house is starting to turn brown along the ledges, though, though, so lower expectations while you can.

Snake Mountain, early September. Note the brown stretches of foliage, probably on ledge.
Snake Mountain, early September. Note the brown stretches of foliage, probably on ledge.

Forecasting a Nor’easter

I’ve heard somewhere that weather forecasting in the Northeast is one of the most difficult areas in the world. That may be, I don’t know, but we have many influences on our local weather-a meandering jet stream, the Atlantic, the Great Lakes, our Green Mountains, even the Arctic itself. On the weekend of February 21-22, the National Weather Service in Burlington was forecasting a potential Nor’easter to hit New England the end of the next weekend, on March 1. I followed the forecasting of this storm closely all week, to see how the forecast and storm would develop through the week. Continue reading Forecasting a Nor’easter

If a Tree Falls…

I’m not much of a Twitterer, although I’ve been called a twit many times.I don’t want to get tweets on my cell-my phone vibrates so violently at the slightest ring or text message that while weeding I end up shrieking like my 10 year old thinking I just weeded a bee’s nest. But I do check some from time to time, MiddBlog being one of my favorites, and they cross-tweeted (is that the right phrase?) a posting from Audrey Tolbert, who with Cody Gohl are blogging their Middlebury summer. (They are going to learn the Vermont secret-we put up with winter for the summer. Not too hot, not too sticky, and, so far this year, not too buggy.)

Anyway, she posted a picture asking“If a tree falls in Midd and there’s no one on campus to hear it, does it make a sound?”. Yes, Virginia, it certainly does.

Silver maple-Hillcrest Road
Silver Maple-Hillcrest Road

This is a Silver Maple tree behind the Chellis House. The storm I reported on last week, well, this was one of the trees that fell over. The picture does not do the size justice, as the trunk of the tree was at least 4′ in diameter. Look carefully, you’ll see about 1-2″ of live wood around the trunk, and the rest was hollow.

Close Up of trunk

One of the surprising things about this tree falling was its aim-it fell in absolutely the perfect direction, missing the woodline separating Hillcrest Road from Adirondack Road, missing Chellis House, the Queer Studies house, and the garage next to Chellis. We couldn’t have asked for anything more.

I wasn’t going to write about this poor tree. I am actually embarrassed by this. While I knew the tree had structural problems, I had no idea the extent of the damage inside the trunk. Look at the close up picture-those are weeds growing between the main stems at the top of the trunk. Large trees like this will often collect leaves there, and eventually grow things. It is the trunk decay that is surprising, and I feel like I should have known about this problem. Two arborists I respect both looked at this tree, though, and said that I had no way of knowing how bad it was, that they see this all the time, one going so far as to say “this is what Silver maples do.” So they made me feel a little better, and now I’m not blushing in embarrassment posting these pictures.

This tree is now cleaned up and gone. We’ve caught up on most of our storm damage, thanks to some very hard work by our landscape department and some excellent outside contractors. The elm I wrote about below Mead Chapel is OK, although more bare now. Once the hanging branches were pruned out there was more left of the tree than I had first thought, so that’s good. Many of the elms had some broken branches here and there, and a handful of other trees on campus had a branch or two break. Overall, not as bad as it could have been.

Irene Still Hanging Around

Like a guest that just won’t leave, the effects of Irene the Hurricane still seem to be around Middlebury. Primarily what we’re watching now is the Otter Creek.

South Street-flooding in the fields

It takes a while. All the headwaters that feed into the creek have been slowly dropping, like my own muddy Lemon Fair River, and so the Otter Creek is rising. How fast? The football team, at Middlebury for pre-season practice, skipped the weight lifting today and went to fill and stack sandbags at Jackson’s on the River (the old Tully and Marie’s to you alumni) ( The old Woodie’s to you older alumni). (Great little article here).

Another stream feeding the deluge is the North Branch River, the one that falls along Route 125, heading up to Breadloaf and the Snow Bowl. Last I heard, the road is still closed (picture here), although Breadloaf is still accessible by back roads.

Otter Creek Levels-via National Weather Service

As I write, the Otter Creek in Middlebury is at 6.9′, within the top 20 crests of all time, and is thought to reach peak tonight around midnight. Not wanting to wait that long, I took some pictures downtown to try and capture the feel of a simply amazing amount of water, brown and muddy, crashing through town. One of our seasonal landscapers was a dairy farmer in Orwell for 30+ years, and in his experience he’s never seen water so muddy. Another guy in our shop is at home, an island experience, surrounded by water on all sides unable to come to work.

On Battell Bridge Looking East
Jackson's on the River
The Falls
Looking under Battell Bridge
The Bottom of the Sluice