Thursday, December 16, 2010

DON'T DICE WITH ICE

By Ken Harrison

I've got me crystal weather ball out again! But I don't believe in guesswork - throw in the factuals and one can achieve a reasonable prediction.

Let's examine the factuals:
1. Many road drains are still blocked/covered by the residue of snow clearance operations.
2. Over the last few days, there has been rapid thawing.
3. Owing to '1' & '2', the run-off is forming standing-water puddling.
4. The run-off and recent drizzle will have diluted any road-salt residue.
4. It is expected to rain tomorrow (Thursday), exacerbating the extent and depth of standing water.
5. The temperature during Thursday night is expected to plummet to around -4 about Brigg. Sleet is expected.

Analysis:
Extremely dangerous driving and walking conditions on Friday + - the last Friday before the festive season.
Standing water will have turned to sheet ice, possibly masked with a veneer of snow.
As a solid form, gritting salt is less effective on sheet ice than friable snow.
Even deep-soled footwear offers little, if any grip on ice - equally applies to tyre treads.

Conclusion:
At least you can clearly see snow and fresh snow is, at least, drivable with care. Sheet ice can give the illusion of 'just a wet road'.
Think twice and don't dice with ice. Take extreme care.

PS In odd and peculiar occasions of such conditions in the past, I've been know to wrap my walking boots in chicken wire to give me that extra grip in an emergency.

No comments: