According to James C. McKinley Jr., "Rare Storm Hits Texas, Causing Chaos for Drivers", NYT 2/4/2011:
Paul McDonald, a forecaster with the service, said the mass of arctic air that had blanketed much of the country had caused three days of frigid weather in Texas as well, freezing the ground. Then overnight, two low-pressure systems moved into the state — one from New Mexico and one from the Gulf of Mexico — and collided with the cold air, producing snow and ice. Though Texas usually has balmy enough temperatures this time of year to melt ice and snow as it hits the roadways, this time the pavement iced over.
“If the air had not been so cold, we would have seen a little light draggle, but cause the air was so chilly it turned into snow,” he said. “We get about one event like this every 10 years.”
Draggle as a word for precipitation, semi-frozen or otherwise, is new to me, and it seems to be new to lexicographers as well. [Update -- and the NYT article has now been edited to replace "draggle" with "drizzle"...]
The OED glosses draggle the verb as "To wet or befoul (a garment, etc.) by allowing it to drag through mire or wet grass, or to hang untidily in the rain; to make wet, limp, and dirty", and draggle the noun as "The action of draggling" or "One who draggles". Merriam-Webster online has draggle only as a verb, glossed as "to make wet and dirty by dragging" or "to drag on the ground". Encarta has the verbal glosses "to make or become wet and dirty: to make something wet and dirty by trailing it along the ground, or become wet and dirty by being trailed along the ground" and "to follow along behind somebody else in a slow and usually undisciplined or slovenly fashion". The American Heritage Dictionary has "to soil by dragging over damp ground or in mud", "to trail on the ground; be or become draggled", or "to follow slowly; straggle".
If Mr. McDonald is innovating — he only needs to talk about this once a decade, after all — he might have been thinking of "drizzle", with the lower vowel signaling a sprinkle (sprankle?) of bigger semi-frozen drops. But those glosses about making things wet, limp, and dirty by dragging do evoke the experience of wading through slush without proper boots.
Anyhow, I sympathize. We've certainly seen both light and heavy draggle this winter in Philadelphia.
[Update -- Michael Ramscar writes:
there's a clue there in the name McDonald -- "draggle" (or "draIgle") is of scots origin i think, and it may be that McDonald is simply revealing his roots. the use of distinctive words for dank, miserable, soul sapping weather is more common in scotland than in any other part of the world i've lived in. there is no mystery as to why. my favorite of the various words like "draggle" that i know is "dreich," which i often heard used to describe the (many) days where it didn't really rain, but rather a clinging moisture hung in the air, soaking one to the bone in a whole new and special way.
The Essential Scots Dictionary has
draigle, draggle v 1 bedraggle, dirty, muddy. 2 mix (flour, meal etc) with water. 3 move slowly or wearily. n a dirty, untidy person.
dralgelt soaked through, drenched.
dralk v drench, soak
drackle damp, wet, misty.
dreich adj 1 dreary, dull, bleak: 'The weather's gey dreich the day'; long, boring, uninteresting. 2 slow; backward; slow to pay debts. 3 depressed
So there's still perhaps some lexical innovation in Mr. McDonald's remark, but this may well be the foundation that it's built on.]
[Update #2 -- Mr. Punch suggests, plausibly, that the weatherman might have said "graupel" (sometimes also spelled "gropple") meaning "small soft white ice particles that fall as hail or snow", and (over the phone) was mis-transcribed by the NYT reporter.]