More proof that rain doesn't really melt snowpack

We have a snow lysimeter at the WSDOT plot that measures outflow from the snow pack. When operating properly we tend to see water move through the snow pack rather quickly when drain channels are established and with some delay when the snow pack is lower density and unconsolidated. We've encountered some problems with the lysimeter- the frequency of freezing rain this year has affected the ability to measure outflow properly.

I know the water is moving through the snow pack (look at the streams and rivers), but the lysimeter doesn't show it properly. I believe this speaks to the bridging effect of ice layers and the lateral movement of water when encountering these layers. The water still moves through the snow pack, just not above our collection area.

Here are some water properties I've used to figure out how much gas to bring on snow camping trips. The thing to note is that it takes almost as much energy to melt ice as it does to bring water at 32degF to boiling. (sorry for just pasting the whole thing and not organizing it, but I'm swamped right now.)

Enthalpy of fusion of water = 335kJ/kg (melting/freezing)
Specific heat of saturated water at standard atmospheric pressure = 4.2kJ/kg-K

Energy to boil water starting from 70degF:
(I chose 70degF because I think REI uses that as a starting temp to compare the energy usage of stoves in liters of water boiled per 100g of fuel)
70degF = 21.1degC delta C = 79degC (or K)
79K * 4.2kJ/kg-K = 331.8kJ/kg

Energy to melt ice at 32degF and bring to boil
335kJ/kg-K+100K*4.2kJ/kg-K = 755kJ/kg

Fuel needed in winter compared to summer just for cooking, not including melting to filter for drinking
(755kJ/kg) / (332kJ/kg) = 2.3 times

Energy to boil water starting from 32degF
100K * 4.2kJ/kg-K = 420kJ/kg
Ratio of boiling starting at 70degF compared to 32degF 0.79
If stove boils 6.5 liters of water starting at 70degF, 6.5 X 0.79 @ 32degF = 5.14

Winter: 2 gallons of water needed per day, how much fuel do I need in oz.
6.50 litersH2O/100g of fuel to boil from 70degf
2.83 litersH2O/100g of fuel melt ice at 32degf and boil
28.26 litersH2O/kg
7.46 gallonsH2O/kg
3.39 gallonsH2O/lb
22.0 gallonsH2O/gallonsGasoline
0.172 gallonsH2O/ozGasoline

2 gallonsH2O
11.6 ozGasoline for 2 gallons of water

Lot's of info, here.

The establishment of the meltwater channels that Stimbuck mentioned probably hadn't happened at all above 4500-5000' for the upper (since mid-Feb) snowpack until just now. I do know that after rain events (not as significant as this one) I would often find meltwater and saturated layers (soon to become ice lenses) downstream from trees, but away from them and also on minor ridges there would be very little water (at Stevens).

So, I certainly have no doubt that meltwater has penetrated the snowpack at lower elevation where it has rained a number of times lately and in forested areas. I wouldn't be so sure about meltwater penetration of sub-freezing snowpacks above treeline. But it would be interesting to find out.
Once these meltwater columns get established they reactivate with each rain or significant warming event. They also tend to facet into a kind of granular but still pretty strong structure between storms.

At Blewett Pass it was always quite a bit different because the snowpack was shallower and far weaker from faceting and minimal overburden pressure, much lower density and much lower bond density (as measured scientifically by how difficult it was to shovel. Since Blewett remains sort of intermountain or even continental between storms (which is most of the time) much of the snowpack is porous and granulated. But then every once in a while a warm storm would come through with little resistance from the SW (look at the low topography between Blewett and the Rainier area). So, it would rain, not much perhaps, but it would take very little to saturate weak layers mostly of facets, and wet snow would be found along the ground. The shallow snowpack and weak structure (possibly with trees or stumps as conduits) allowed penetration of meltwater full depth within a half day or so. With cooling the snowpack would quickly gain strength.

But I'd have to say I've dug very few pits of any depth at elevations above treeline and where the snowpack is colder.

Freezing rain is interesting because it often starts out as fine mist with snow and air temperatures well below freezing. This causes a crust to form generally without vertical penetration of meltwater - it immediately freezes. The crust is then re-inforced by additional moisture and can often be quite impermeable. The side effect of this process is that dry, cold snow is adjacent to 32 degree water as it refreezes, so freezing rain crusts are often quite planar weak layers that are significantly faceted because of the sharp temperature gradient at the crust. They often don't benefit from meltwater penetration, snow layer warming, and the refreezing process which acts to initially strengthen the snow below a typical crust. Faceting happens in the latter case, too, but probably especially without the warming effects of penetration. It is usually easy to pick off a freezing rain crust from the dry snow (quickly faceted) beneath. Both of these layers tend to facet over time because of the difference in thermal conductivity (pore space and bond density) between the two radically different layers. This also happens when new snow falls onto the crust (which is probably the biggest problem we've been dealing with lately. But freezing rain crusts are among the worst.

I'll add one more thought: Cornices could also act as conduits and very important ones, too, since meltwater penetration to weak layers would be happening in a starting zone.

The photos that have been posted elsewhere of the mud slides in Icicle Canyon are pretty good indicators that there were probably lot's of deep or climax avalanches along the east slopes. That kind of a mudslide is not an everyday occurrence east of the crest although the Icicle surely still suffers from the 1994 forest fires.