Explain this

cram1971

Ok haven't seen this before my weather station is showing a westerly wind direction but the rainfall radar is showing the clouds moving in a east to west direction across he Irish Sea

www.howthweather.com

srocliffe

I'm no expert but I think I saw a similar question come up the other day. Basically I think wind direction is not consistent at all altitudes, so at ground level the winds could be westerly, but at upper levels, where the clouds with the precipitation are, the wind direction can be easterly.

Calibos

Have a look at the Sat24 animations. You can actually see areas of cloud criss crossing each other. Means they are different types of clouds at different altitudes blowing in different directions by different direction wind. Now do you see the.....eh difference

Bloody great thing too for me by the Seafront in Bray. So early in the Winter the sea is still quite warm. The first few hundred feet of air over the sea is heated by the sea. This sea warmed air can intrude inland a mile or two and can make it too warm for snow right on the coast and we might get sleet or even rain.

We haven't seen that kind of marginality this cold spell because while the high level winds are blowing easterly and delivering the Snow to us from the east, at the same time the surface level winds have been blowing westerly pushing air chilled by the cold and often snow blanketed land over us and pushing back the warm maritime air away from the coastal fringes meaning that snow coming ffrom the east wind doesn't have to fall through warmer air on its way down and risk turning to sleet or rain in the process.

cram1971

That is what I expected.

Probably explains why we are getting the thunder snow also

Rabble Rabble

Calibos wrote: »

Have a look at the Sat24 animations. You can actually see areas of cloud criss crossing each other. Means they are different types of clouds at different altitudes blowing in different directions by different direction wind. Now do you see the.....eh difference

Bloody great thing too for me by the Seafront in Bray. So early in the Winter the sea is still quite warm. The first few hundred feet of air over the sea is heated by the sea. This sea warmed air can intrude inland a mile or two and can make it too warm for snow right on the coast and we might get sleet or even rain.

We haven't seen that kind of marginality this cold spell because while the high level winds are blowing easterly and delivering the Snow to us from the east, at the same time the surface level winds have been blowing westerly pushing air chilled by the cold and often snow blanketed land over us and pushing back the warm maritime air away from the coastal fringes meaning that snow coming ffrom the east wind doesn't have to fall through warmer air on its way down and risk turning to sleet or rain in the process.

Good explanation, dude.

Calibos

I post on the Astronomy forums too where there are always reports of red/orange ufo's in the sky. We always explain that these are Chinese Lanterns. Invariably the posters say that they couldn't be Lanterns blowing in the wind because what they saw sped up and slowed down, hovered, changed direction and headed of in the opposite direction etc.

Interestingly the explanations posted above explain the apparent 'Controlled' behaviour of Chinese Lanterns too.

As they rise up in the sky they often climb through different levels of air with different or even opposite wind directions.

The explanation never convinces of lot of those posters though. They want to believe they saw something unique in the night sky