AFLM, typically you don't need snowshoes or crampons on Whitney. When it's that bad in winter, sure. But probably 60-70% of the year it's just not worth the weight - you've only got (maybe) 1/2 mile of snowpack on the entire Portal to Summit route.
+1
Good raingear, warm clothes and food are much more important.
At the lower elevations, a fire can be made for warmth and to
melt snow.
Having been caught in a sudden snow storm on the East Face
route of Mt Whitney (http://en.wikipedia.org/wiki/East_Face_%28Mount_Whitney%29) I learned that storms
from the west are hidden from view by the cliff face itself.
Combined with high winds and lightening streaking down the
face, it can make for a very exciting retreat. We had to leave
a dozen or so pieces of climbing pro to safeguard the suddenly
slippery holds. Flashlights were critical as the descent
took a long time.
The storm came upon us in less than an hour. This was in September. We started the climb in long johns and sweaters
before dawn, changed to shorts, then back to warm clothes
and rain gear.