I can’t seem to find a straight answer, but I get the impression it is about 1" a day when it is above freezing.
Does it melt faster in rain as opposed to no rain?
What role does temperature play in it (assume 33F vs 50F)? Or the angle of the sun to the snow, or the material the snow is on (asphalt vs grass vs concrete, etc)?
Is just assuming 1" a day in 40-50F weather, and assuming it occurs faster on asphalt and concrete just a reasonable collection of assumptions w/o needing much more detail?
But what role does rain play? Will snow melt at 2" a day if it is raining and above freezing, or is it closer to 1.1"?
Does the rain break up the snow, or is it more for the same reason sweat transfers body heat from the body, because water holds more heat?
How could it be the latter, isn’t snow just water? Also isn’t the atmosphere when full of snow and rain going to be at a high humidity, which would make it harder for the snow to melt?
Does the physical impact of rain on snow have any difference in how it melts (ie does snow that turns into swiss cheese due to rain melt faster than snow that is even)?
I’m guessing you don’t live where it snows. As Xema said, it depends on the kind of snow, as well as if there’s a sheet of ice over the top of it. That glaze will make it take longer, it’ll reflect the sun and sheer the rain off.
Of course the temperature makes a difference. If it’s 33 out, it’s really not going to melt. It’s got to be, I dunno, 37ish, before the snow starts getting melty, 40ish is about when you start seeing water running off into the road.
If it’s raining, like really raining out, that’ll get rid of a lot of snow really fast. In fact the first really big rain in spring, if there’s still a lot of snow out (more than a foot), seems to be the day that the sewage department dreads since they get all the water from the rain PLUS all the snow from winter all at once and end up with problems.
As for the surface, yes, that makes a difference as well. The grass will go last, the concrete and asphalt will melt faster. I’d guess that asphalt would melt snow faster than concrete since I think it holds heat better, but it’s hard to say since I don’t usually see them side by side in place I can easily compare them.
Lastly, yes, the sun pounding down on the snow will melt it faster as well. This is most noticeable near buildings/houses. The area closest to them where the sun never really hits might have snow for weeks longer than the area out near the street or on the other side of the house if it never gets warm enough to melt it w/o the sun.
I’m sure it helps, physically, but the rain is above 32 and the snow is below 32, so the water hits the snow, the snow absorbs some of the energy from the rain and in doing so, melts.
Same thing happens if you put some ice in your sink and run water over it, even really really cold water, it’ll still melt pretty quickly.
Living on the edge of the prairie has taught me that the warmer the day, the faster the snow melt. Here in MN, we had a single-day snow melt event that flooded my basement and caused problems for many homes and businesses. I’ve never had this problem in other years when the snow melt was slower.
How deep the frost is in the ground affects the melt as snow doesn’t just melt on top, but on the bottom as well. How dense the snow pack is and if there are layers of ice in it as well as the type of snow makes a difference as well.
I’m not an expert to be able to throw exact figures at your questions. In fact, I’d like to see those answers myself. I’ve just got lots of experience having lived here my whole life and been involved in the sport of ice racing, where the thickness and density of lake ice and the snow covering it has to be taken into consideration when preparing for an event.
Mark Seeley may be able to answer some snowmelt questions.
Piling up and compacting the snow makes it last longer, too. After the blizzard of '78, all the shopping centers had huge piles of snow from the snow plowing. Some of those piles lasted until late April.
I’m truly not trying to be snarky, but that’s like asking “How long is a piece of string?” It defies an answer.
All the things you’ve mentioned, as well as those mentioned in the above replies, and probably a few other things that haven’t come to mind yet, are variables that will affect the melt rate. I can’t imagine anyone’s come up with a formula that accurately calculates all those factors, and I seriously question if it’s even possible to do so.
Here in Kansas City one of the radio stations has a contest for predicting what day the plowed pile beside one of the libraries will be totally melted away. IIRC for most years it’s in April as well.
Where I live there are times when the snow lies several feet deep. Temp can go up to 5 degrees above zero with little to no measurable melt back. Whereas if it were only a couple of inches on the ground, the same temp would melt it all away.
The answer to your question is, in fact, it depends!
Why would humidity effect the way something melts? Evaporate I could see, but melting? Things easily melt in the ocean, why wouldn’t they easily melt in 100% humidity?
Wind speed is another important variable. It is technically incorrect to say that the blowing air carries the cold away (just as centrifugal is technically incorrect) but has great explanatory force. Also the color matters. In early spring when a lot of the snow has melted, all the accumulated dirt in that snow is now on top and the black snow melts much faster. It was worse before stoop and scoop laws because you also had several months dog shit in the snow.
No humidity of the air does not affect melting… much… well if the air was the same temperature, and pressure, which means “All other things being equal”, then the increased density should increase the rate of melting.
Troll though ? you know that humidity is either relative or absolute, so why mention the ocean, with its 100% absolute humidity … but if not, you aren’t asking here ! You also know the difference between effect and affect, and thats not really for this thread either.
I recall in physics when discussing velocity for calculations for falling objects the teacher said in higher physics classes you also had to calculate things like wind which made the calculation much harder. But he said using the basic equations was enough to get a fairly accurate answer.
So I assume there is an equation, maybe the complex one has ten or more variables but maybe a simplified one that is 90% accurate can be made that only requires five or less variables. Things like temperature, solar radiation, level of rainfall, etc.
You’ve already mentioned many of the factors. The temperature of the ground will make a difference also. Rain changes the equation based on the amount of rain and the temperature of the rain when it hits the snow, and how well it drains. You ask for the melt rate for one day. Temperature can fluctuate greatly in the period of one 24 hour day. If the snow that begins to melt in the daytime freezes into ice over night it could take a lot longer to melt.
I think Joey P is right that you don’t live somewhere where it snows, otherwise you wouldn’t think there was anything like a daily rate of snow melt. Sometimes it seems to disappear overnight, sometimes you can’t believe it’s still there.
Well, I don’t know any particulars, but I have zero doubt that people are trying, and even have succeeded (for an appropriate value of ‘accurately’, averaged over a large-enough area). “How much snow pack melted yesterday” is a question that lots of reservoir managers, watershed researchers, climatologists and others would really like to know; some of them are trying to come up with answers.
I’ve always thought that the saying specified “driven” snow because the snow is only clean while it’s still falling. The longer it’s on the ground, the nastier it gets.
Snow doesn’t all “melt”. When the sun shines on it, it can turn directly from solid to vapor, skipping the liquid phase (sublimation). This can occur when the temperature remains below freezing, provided the snow gets a substantial amount of direct sunlight. In the spring, when the sun is high and sunlight direct, the snow can disappear very quickly, with little or no water runoff.