The Whites too...
The warning referenced by the OP is for the DAKs, but similar conditions exist in the Whites.
Most avalanches occur on slopes between 30 and 60 deg and can occur on slopes down to about 25 deg. (Ref: FOTH)
For most hikers, a good strategy is simply to avoid (and avoid being below) slopes which are steep enough to avalanche. (Many fatal avalanches are triggered by humans, frequently the victims themselves.)
One can estimate the average slope angles from a topo:
* 25 deg = 2460 ft/mi
* 30 deg = 3050 ft/mi
* 45 deg = 5280 ft/mi
* 60 deg = 9150 ft/mi
Make sure you check the steepest part of your route...
The best field method for estimating the slope angle is an inclinometer (built into some high-end compasses) or a simple method using the length of one's ski poles:
* 1/2 pole up and 1 pole horiz: 27 deg
* 1 pole up and 1 pole horiz: 45 deg
* 1 pole up and 1/2 pole horiz: 63 deg
Reading:
* Ferguson and LaChapelle, "The ABCs of Avalanche Safety"
* "Mountaineering, The Freedom of the Hills"
* Daffern, "Avalanche Safety for Skiers & Climbers"
* Perla and Martinelli, "Avalanche Handbook"
Formal training is available from a number of sources.
Daily avalanche bulletins for Tuckerman and Huntington Ravines are available at
http://www.mountwashington.org/avalanche/index.html.
Interesting reading, even if you are not planning on going into the ravines.
Doug