minus temp no frost
minus temp no frost
Some one please explain this phenomena to me. Temps got down to -2.4c ish but no frost on windscreen or grass as I usually see.
I know it must be to do with relative humidity and stuff, but would like a concise and lucid explanation
ta
I know it must be to do with relative humidity and stuff, but would like a concise and lucid explanation
ta
Re: minus temp no frost
It was the same here in Southampton last night?flounder wrote:Some one please explain this phenomena to me. Temps got down to -2.4c ish but no frost on windscreen or grass as I usually see.
I know it must be to do with relative humidity and stuff, but would like a concise and lucid explanation
ta
_3c and not a hint of frost.
I think the humidity was rather low so that was the reason.
rgds Billdango
Re: minus temp no frost
If the temp doesn't get as low as the dewpoint you won't get frost because no moisture is formed on surfaces to freeze and turn all sparkly white.
It can be minus 6 but if the dewpoint is -8 then the air is dry and cold rather than wet and cold.
Don't make the mistake of thinking ground frost is frozen surface water, it isn't. It's the dew formed by the condensation process that occurs when the air temperature and the land surface temperature are at odds and condensation occurs then freezes.
I learned that off Stephen the other day so just passing it on. Blame the teacher if I've got it wrong
It can be minus 6 but if the dewpoint is -8 then the air is dry and cold rather than wet and cold.
Don't make the mistake of thinking ground frost is frozen surface water, it isn't. It's the dew formed by the condensation process that occurs when the air temperature and the land surface temperature are at odds and condensation occurs then freezes.
I learned that off Stephen the other day so just passing it on. Blame the teacher if I've got it wrong
Re: minus temp no frost
Right thanks guys, they were the answers I expected. Just wanted clarification
Re: minus temp no frost
Was the soil hard and puddles frozen?
Re: minus temp no frost
Low humidity, low frost. My humidity levels were down to 34% today. Driving home at 11pm tonight no frost to be seen anywhere. My weather station told me -3c and 67% humidity. It's always higher at night but that level is still too low for frost on vehicles. You might see a little on the grass as, holding moisture, it will be more humid at ground level.
Re: minus temp no frost
yes and no because there weren't any puddlesConifers wrote:Was the soil hard and puddles frozen?
Re: minus temp no frost
does the lack of frost make any difference to plant damage at any given temperature
ie
-6 with frost is worse than -6 without (or visa versa)
ie
-6 with frost is worse than -6 without (or visa versa)
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Re: minus temp no frost
I have have had - 6 with frost last night !Mr List wrote:does the lack of frost make any difference to plant damage at any given temperature
ie
-6 with frost is worse than -6 without (or visa versa)
AKA - Martin
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Wish list - Big Palms or Dicksonia antarctica's but open to anything really.....Cash Waiting !
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Re: minus temp no frost
We get these cold dry NE winds here periodically every late winter and spring. The main problem apart from wind chill factor is the low humidity, which then desicates the ground and plants. I'll be out there dousing the Dicksonia antarctica down as soon as this freeze is over..... provided I'm not under 6 feet of snow that is
Best regards
Dave
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Dave
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Roll on summer.....
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Re: minus temp no frost
No very humid here as well with the lowest point yesterday with just below 30%. It's swinging between the 30-40% since the cold started. Lows between the -5/-10 and windchills till -20C. Now I do know again why I hate winter...
But at least no frozen car windows as well.
But at least no frozen car windows as well.
Re: minus temp no frost
i'd like to know this too!Mr List wrote:does the lack of frost make any difference to plant damage at any given temperature
ie
-6 with frost is worse than -6 without (or visa versa)
I had over -4*c last night and ground didnt have a trace of frost, but car did have a little frost on the windscreen, but side windows were all clear.