Comments on: the hazy blur of the brand new day http://jessamyn.com/journal/2009/01/the-hazy-blur-of-the-brand-new-day fifteen years of jessamyn Sat, 08 Jun 2013 15:16:23 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Michael Dorfman http://jessamyn.com/journal/2009/01/the-hazy-blur-of-the-brand-new-day/comment-page-1#comment-19930 Michael Dorfman Thu, 22 Jan 2009 09:59:30 +0000 http://www.jessamyn.com/journal/?p=280#comment-19930 "I don’t quite understand the mechanics of ice dams" Ooh! I know this one. Prologue: Layer of snow on slanted roof. Act I: Sun comes, melts a small portion of snow. Since water flows down, snow at the bottom of the roof gets wet (wetter than the snow higher up.) Act II: Sun goes away, wet snow re-freezes to ice. You now have snow on the higher portions of the roof, and a thick chunk of ice lower down on the roof. Act III: Sun comes back. Snow starts to melt (faster than ice), flows down, but is blocked by the dam of ice. Epilogue: Water begins to accumulate upward (since it can't go down) and comes through the slates/shingles (which depend upon gravity for their seal) and, ultimately, down through the ceiling. “I don’t quite understand the mechanics of ice dams”

Ooh! I know this one.

Prologue: Layer of snow on slanted roof.

Act I: Sun comes, melts a small portion of snow. Since water flows down, snow at the bottom of the roof gets wet (wetter than the snow higher up.)
Act II: Sun goes away, wet snow re-freezes to ice. You now have snow on the higher portions of the roof, and a thick chunk of ice lower down on the roof.
Act III: Sun comes back. Snow starts to melt (faster than ice), flows down, but is blocked by the dam of ice.
Epilogue: Water begins to accumulate upward (since it can’t go down) and comes through the slates/shingles (which depend upon gravity for their seal) and, ultimately, down through the ceiling.

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