As many boardmates stated, I also think that the snow cannot happen in South China cities listed in title.
Case in Hong Kong:
There is shower and cold weather in Hong Kong right now.
"We do not want sunny and warmer weather!" (many different choices for different people!)
In fact, according to the weather report in China, the cold weather has been continuing until Chinese New Year.
Therefore, it is true that there is rain or shower (but no more sunshine and warmer weather!). However, no matter how cold the weather, it seems not possible snow in Hong Kong. If it were possible, then the weather became abnormal; I beleive that some people, especially seniors or patients, can die.
So, we should pay more attention to look after someone who is in needed during the cold weather.
Latest news: There will be sunny period after 2/6. Still no sunshine is valid on 2/4 and 2/5. However, stop warm weather after the sun shines. The procedure is called sunny maintenance.
Fact: There may be up to 15 - 16 degree C between 2/4 and 2/5, when the sun has not been shining. However, We expect only (up to) 14 degree C after the sun shines on 2/6. Do not expect the weather is good on 2/3.
If the statement is false, than you just change the date that is underlined listed above.
The latest news (2/3): We do not want the warmer weather any more because the cold weather has been continuing since 1/24/08; the weather will not be warmer except:
1. The sunny period has been continuing since 2/6/08, and
2. The temperature goes up to 18 degree C when there is one sunny day after 2/11 or 12/08.
If one of the points listed above does not hold, then no such warmer weather is available.
What will happen next?
There is only sunny intervals (si), but not sunny periods (sp) or better (except 2/9/08). Therefore, the weather cannot be warmer until next week. Furthermore, only si is available after 2/10. Do not expect that there will be big sunny days in Hong Kong! :loveliness:
(many different choices for different people!) 
