The Next Dose of Winter to Hit Us!

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gllitz
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Re: The Next Dose of Winter to Hit Us!

Unread post by gllitz »

Thank you, kind sir, for that...I am sure I speak for many when I say I appreciate your explanation.
Good stuff.
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Re: The Next Dose of Winter to Hit Us!

Unread post by Paul Mallinson »

Yes, Tony is right. there are many variables to consider. One of the main issues is when will the bulk/heaviest precip occur and at what temperatures/freezing level. If all the precip comes when the regime is still quite warm (freezing level still high) then of-course most will be rain at the lower levels (below say 500 metres). If the heaviest precip is timed when temps/freezing levels have already fallen considerably, then there will be less rain and more snow - lower down. Other aspects are how dry the low level air is at first (will the snow penetrate further because of the dry air - evaporation into dry enables snow to fall to a lower level), or, will there be moderate or heavy precip in the face of little or no cold advection. Then the snow level has a chance of lowering due melting - robbing heat from the air. Its a tricky affair.

I read a comment the other day about how much more simple it is in northern continental areas. I used to work in Canada for the weather service there. When it got cold enough into the winter, you basically went for snow right off - very straight forward! However, there is always a trade off. This was that when a nose of warm air came in aloft (upper warm front), and depending on the temperature structure aloft, you might be facing a freezing rain situation. Such a condition is not nice. It is dangerous for aviation and makes getting around on foot or in a car very difficult.

So every forecast location has its problems!

Paul
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Re: The Next Dose of Winter to Hit Us!

Unread post by gllitz »

I love this stuff...this is GREAT! Many thanks to you as well, Paul...
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Re: The Next Dose of Winter to Hit Us!

Unread post by CHCH Weather Chaser »

The Rain Radar for Christchurch shows heavy stuff to the south and west of us but it seems to all be by-passing us inland. Its just getting further away. Especially looking at the 8pm one.
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Re: The Next Dose of Winter to Hit Us!

Unread post by gopolks »

Isnt it suppose to come in tomorrow afternoon/night?
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Re: The Next Dose of Winter to Hit Us!

Unread post by CHCH Weather Chaser »

Its meant to spread north this evening with southerly gales and rain developing.
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Re: The Next Dose of Winter to Hit Us!

Unread post by gopolks »

Oh, I thought it was a thursday night/friday thing.
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Re: The Next Dose of Winter to Hit Us!

Unread post by tich »

Interesting to note a sheltering affect of the Port Hills today with that low cloud and drizzle, out towards Godley heads there was patches of blue sky all day even at 5pm when leaving course in town.
I wonder how much effect as a rainshadow Banks Peninsula has - Chch may be somewhat sheltered in a southeasterly flow, which is what the airflow looks like tomorrow.
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Re: The Next Dose of Winter to Hit Us!

Unread post by CHCH Weather Chaser »

Thursday night/ friday was when the models Yesterday were suggesting snow possible to near sea level but thats not looking likely anymore. Maybe 200-300m hard to know.

This issued by metservice.
"HEAVY SNOW WARNING
AREAS AFFECTED: CANTERBURY FOOTHILLS. In the 9 hours from 3am to midday Thursday, 15 to 20cm of snow is expected above 500 metres and between 6am and midday around 10cm is possible down to 400 metres,with smaller amounts of wet snow or sleet as low as 300 metres. By late morning only light snow showers should remain but these may add another 5cm of snow above 400 metres by midnight Thursday. "
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Re: The Next Dose of Winter to Hit Us!

Unread post by gopolks »

So its going to be quick then.
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Re: The Next Dose of Winter to Hit Us!

Unread post by CHCH Weather Chaser »

Its going to hang around but as more showery activity, overnight tonight and tomorrow is predicted to be the worst of the days and then occassional rain or showers fri-sun at this stage. Snow levels by friday are more like 600m.
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Re: The Next Dose of Winter to Hit Us!

Unread post by gopolks »

Heck thats not even the port hills, maybe on the tops of banks penisula.
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Re: The Next Dose of Winter to Hit Us!

Unread post by CHCH Weather Chaser »

Yes, things can change i guess. Its certainly weakened though to how models were suggesting last night. (bugger) Just as i am writing to you here in Halswell (south chch) the southerly is picking up big time! Gusting to 46km/h suddenly. The 9pm radar is due to update within next ten mins or so, maybe something is near by but at 8pm it was looking far too inland.
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Re: The Next Dose of Winter to Hit Us!

Unread post by NZstorm »

Obviously some orographic enhancement in the foothills, hence the snow warning.
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Re: The Next Dose of Winter to Hit Us!

Unread post by CHCH Weather Chaser »

and thats not looking the case at all is it?
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Re: The Next Dose of Winter to Hit Us!

Unread post by gllitz »

Just watching the sat loops and watching how there is cloud forming off the West coast of the SI from the strong southerly winds...I've seen the gaps of "clear" air before, but I can't recall seeing the clouds blowing off the Alps like that before...almost a "reverse NW'er" effect? Anyone care to explain? Just curious, is all...
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Re: The Next Dose of Winter to Hit Us!

Unread post by Manukau heads obs »

almost a "reverse NW'er" effect
you have just exlained it ;)
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Re: The Next Dose of Winter to Hit Us!

Unread post by TonyT »

MarkThomas wrote:Yes, things can change i guess.
Mark, print that sentence out in really big letters and stick it to the wall above your computer for me will you? ;)
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Re: The Next Dose of Winter to Hit Us!

Unread post by CHCH Weather Chaser »

lol, haha. How are you seeing Sunday Tony? Weather watch is saying snow to South Island with this Sub Tropical Low. Its at 962hpa on Sunday. How are you seeing it?
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Re: The Next Dose of Winter to Hit Us!

Unread post by Ryan Thomas »

962... That seems very very low.. Can't recall seeing anything that low before, or never paid attention
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Re: The Next Dose of Winter to Hit Us!

Unread post by CHCH Weather Chaser »

Im with you Ryan, ive never seen something that low either. Im sure there must have been though or it'd be a big talking point lol
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Re: The Next Dose of Winter to Hit Us!

Unread post by melja »

MarkThomas wrote:lol, haha. How are you seeing Sunday Tony? Weather watch is saying snow to South Island with this Sub Tropical Low. Its at 962hpa on Sunday. How are you seeing it?
How bout you go read his forcast Mark then i gess you will know all you need to know ](*,)
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Re: The Next Dose of Winter to Hit Us!

Unread post by CHCH Weather Chaser »

Yes, i have been there done that but this system has rapidly deepened from 1pm this afternoon when he did his 12 day forecast :D. Anyways im off to bed, hopefully we hear heavy rain on the roof during the night. Goodnight everyone!
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Re: The Next Dose of Winter to Hit Us!

Unread post by Storm Struck »

Good riddens we silenced the prevailing southerly ;) :lol: .
Yes the low at the weekend if it swings its arm further south nicly it could spell some nasty weather, but looks quite bad for the lower north island and Kaikoura etc.
The rainfall should increase very soon, if you note the model runs don't get significant until midnight onwards anyways.
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Re: The Next Dose of Winter to Hit Us!

Unread post by Razor »

Here in Dunedin it has been dry for the past few hours. Relatively mild too for this time of year, I had expected a bit more precipitation but maye it'll kick in tomoorw, not so familiar with the local effects here
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