The natural environment and history of Kalispell’s West Valley area
by Skip Via
skip@westvalleynaturalists.org
Over the past few years, we’ve presented several articles here on our web site dealing with different forms of ice–or more properly, frozen water or water vapor. Here are some:
In this article, we’ll take a look at another icy phenomenon–Needle Ice.
by Skip Via
skip@westvalleynaturalists.org
I woke up on December 29, after two days of dense fog, to see everything–leaves, grasses, fencing wire, pine needles–coated in a beautiful layer of hoar frost.
But wait…hoar frost occurs only in very specific conditions: namely cold, clear, and windless nights with low humidity, when the rapid radiant heat loss from surfaces causes water vapor–not liquid water droplets, as in fog–to form delicate, needle-like crystals on those surfaces. The previous two nights had been anything but cloudless with low humidity. You could feel the cold fog droplets on your face when you walked.
But it sure LOOKS like hoar frost. What’s going on here?
Continue Reading →by Skip Via
skip@westvalleynaturalists.org
Editor’s Note: A followup to this article, with more accurate information on how different varieties of frost form, is available here: Hoar Frost, Rime Ice, or Something Else?
A few days ago, driving around West Valley, I remarked on the beauty of the hoarfrost that had coated some Ponderosa pines along the roadside. That got me wondering about the nature of hoarfrost and how it forms. It turns out that some of what I have been calling hoarfrost is, in fact, not hoarfrost, but rather rime ice. The difference is not important for the casual observer, but it can be important meteorologically.
Continue Reading →By Skip Via
skip@westvalleynaturalists.org
Walking through the woods in a graupel shower this afternoon prompted me to do a little more research on the phenomenon. Just what is graupel, anyway, and how does it differ from other forms of frozen precipitation?
Continue Reading →by Skip Via
skip@wastvalleynaturalists.org
Pat Jaquith’s lovely Winter Wonders post prompted me to post these images taken on 1/7/21 at the Happy Valley State Trust Lands (see Locations) after a light snow melt on a bluebird afternoon.
by Pat Jaquith
pat@westvalleynaturalists.org
Snow bales? Ice needles? Hoar frost? Snow serpents? Pink snow? From dawn to dark, winter weather provides us with lots to marvel at.
Continue Reading →By Skip Via
skip@westvalleynaturalists.org
The Dec 24 2020 edition of the Daily Interlake has a useful downloadable supplement (by Scott Heisel of the Lake County Leader) on winter birding day trips in the Flathead Valley and beyond. It’s a little difficult to locate, so if you missed the print edition, here is a PDF file of the article.
Continue Reading →by Pat Jaquith
pat@westvalleynaturalists.org
Many birds migrate from a winter home to take advantage of an abundance of insects, longer periods of daylight for scavenging, and increased success in raising a brood in the north. As winter arrives and insects become scarce their survival depends on their returning to a warm climate where insects are available.
Birds that depend on non-insect food sources and move from place to place in response to the availability of food sources, independent of season, are referred to as nomads. They often travel in flocks of the same species, searching out food, and moving on.
by Pat Jaquith
pat@westvalleynaturalists.org
The sight of a Mourning Cloak butterfly is a sure sign of spring to me! In late fall, they crawl behind loose bark on a tree where they increase the level of glycerol in their blood, convert excess water in their bodies into a gelatin-like substance that doesn’t freeze, and spend the winter. As spring warmth arrives, they reverse those properties and start flying sooner than many others! Many butterflies endure the winter as eggs, caterpillars, or in a chrysalis. A few, like Monarchs, migrate to warmer climates.
Continue Reading →by Pat Jaquith
pat@westvalleynaturalists.org
It’s fall already; raptor fans have been counting the migrating raptors at various mountain top sites for a few weeks, and I’m already noticing fewer soaring birds in the West Valley. Any day we may see Rough-legged Hawks that have migrated thousands of miles to call this home for the winter.
Continue Reading →