Water in Earth weather conditions.

(third planet of sol, somewhere in the eastern arm of the milkyway)

Water is the substance of main importance in earth weather. Water boils at about 373Kelvin, 100 degrees Celcius or 212 Farenheit but it evaporates at any temperature. This evaporation takes place at more fast at high temperatures, but will also take place far below the freezing temperature of 273Kelvin, 0 degrees Celcius or 32 Fahrenheit.

The boiling temperature and the evaporation speed is dependend on air pressure as well.

A model can be visualised by imagining the gas molucules as balls dancing round at various speeds. The temperature is a measure for the average speed and the air pressure as the number of balls per volume. At any temperature above 0K gas molecules bounce around hitting each other and the walls of the enclosure pretty hard. Substances as water have rather loose cohesion enabeling the gas molecules to break surface molucules from their crystalline structure. These loose molecules then become part of the gas. More space between the gassy balls will enable the water balls to keep bouncing.

The other way also takes place, gassy water molecules hitting other slow water molecules and by fitting into the structure and bouncing on the right angle they can cling to the water surface. With lots of gas molecules the heavy water molecules will be slow and stay water.

Most water vapour just drifts in the air but if the conditions are right they can condensate into clouds. The combination of temperature and pressure makes them form tiny drops of water, small enough to float on the air. The importance of clouds on the weather will be left to the imagination and some of the next chapters.

The water in clouds does not remain tiny drops. Most clouds consist of a mixture of drops and icy grains. The ice particles do vary in shape and size from a few molecules and solid compact formed crystals to long needles or featherlike dendrite structures with numerous water molecules. The water drops evaporate and freeze again depending on the conditions, they will rarely drop down to the earth as water. If the size and surface tension grow over a certain limit, the frozen particles go down as if they 'remember' they ought to fall. On their way down they often bump into other particles gaining in size and electrical charge.

Height (low pressure) and temperature (far below freezing) conditions form stratospheric clouds consisting of flat nearly transparant crystals floating at very high speeds through the upper layers of the atmosphere.
Lower clouds often consist of liquid phase water fog with very big nearly falling drops.
Inbetween clouds are molded by air currents. Some form fountainlike structures on the top where upgoing airstreams blend the heavy drops with higher formed ice particles. These cumulus clouds can gain charge differences of millions of Volts by the bounces of the particles in the blender. Colliding air flows can feed these kind of clouds to grow out into thunderstorms.

The Inuit have some 50 words for snow they say. After a little study I am less impressed by this fact as their vacabulary for the falling stuff seems rather limited.

In english we know fog, rain, hail and snow. By enhancing the words we also get lots of different terms.

(Hey, I could use some help as my vocabulary does not extend beyond the official forecasting words by very far)

Downfall

Naming	Falling	Landing
Dry fog	-You can not see through the cloud as it is dense but the evaporation goes faster than the fog can make something wet. This will happen in windy conditions for most of the times.	-Does not leave a visible trace on a surface, hygroscopic objects will get moist.
Mist	-As this dry fog comes flowing in from over a stretch of water, creating a spooky atmosphere, strange low pitched unrecognisable sounds and dimmed light.	-Also does not leave a visible trace on a surface, hygroscopic objects will get moist.
Light fog	-A little haze preventing the laundry to dry	-Just not making more then drops on a flat surface.
Freezing light fog	-This will be experienced as light tickling under freezing conditions.	-All surfaces will be covered by a thin layer of ice crystals.
Cotton flake fog	-If the wind blows the fog into dense and thin layers, curving round obstackles. The experienced temperature swinging up and down with the density of the fog.	-Only the wind faced side will get little moist.
Heavy fog	-The water drops are so close together you can not see the other side of the street.	-Leaves and flat surfaces start dripping, clothes and hair get wet if endured exposure takes place.
Heavy freezing fog	-This is somewhat funny under freezig conditions as the ice needles will tickle your face just hard enough to be noticed .	-And surfaces are miracelous covered on all sides with beautiful tiny structures of ice crystals, ripe.
Milkshake fog	-Swift moving curtains of dense and light fog flowing over the land creating a constant change in perspective. Very dangerous when driving, especially if the temperature is close or below freezing.	-Below freezing temperatures this will create fascinating ice crystal structures alongside and downwind objects.
Drizzling rain	-You can just see the rain falling	-You can not see the single drops on a flat surface.
Wet wind	-You can hardly notice the downfall as the few tiny drops move too fast to be seen	-All surfaces get wet on all sides.
Light rain	-The tiny drops fall but you can walk between them (cats do)	-Surfaces will get wet and you can just see the drops.
Tender rain	-The drops are still small jet there are so many you will always get wet	-On surfaces small lines of flowing water drip at constant rate.
Summer rain	-After days of warm dry weather a slow steady mostly short rain with rather big drops.	-At first the surfaces do not get wet at all, the drops evaporate as they touch. A damp moist smell promising a releive for the dry plants and earth. Cracks in the earth form drainage to deeper levels. Be sure to protect yourself before the temperature drops as you will get wet pretty fast.
Druiling rain	-Rainfall for hours with varying drop size, everything will get soaked really wise to use an umbrella or alternative water proof cover as there will be not enough time to dry your clothes.	-All surfaces are covered with a film of water, immediately flowing into streams and creating constant flows of water over edges.
Pooring rain	-Constant rainfall for extended periods, everything is already soaked and you wonder if your underpants will stay dry this time.	-All surfaces are covered with a layer of water, constantly flowing away in streams.
Outbreak of rain	-Sudden starting and mostly stopping rain with big drops. If you doubt for a second to take shelter you will be soaking wet.	-Little rivers and streams will flow around your feet perhaps even before the drops fall where you stand. Sometimes the outbreak will appear only on the other side of the street, you can feel the damp moist air coming toward you or even some updancing drops just before the rain hits (or mis) you.
Bad weather	-Repeatedly starting and sometimes stopping rain with big drops. Blown by the wind these drops will hit your from the side. You can not miss it if there is a clearance when you go out, you will be hit before you get in.	-Flows of water go from pool to drainage everything will be wet and dripping. Hiding under a tree is unwise to stay dry as the trees drip alternating with the clouds.
Heavy rain	-The drops are falling at such speed down you do not have much advantage by using an umbrella as the upbouncing water soakes you from below.	-Surfaces are covered by clouds of upbouncing drops, most tiny and creating a foglike blanket over the streets.
Rainy gails	-During the passing of the front the rain comes just after the first blows of wind. Umbrellas do not give any shelter as the curved shape will suck the rain under, or they are pointed in a wrong direction anyways.	-Try to pretent you do not have a surface to get wet, you will fail.
Mousson rain	-Yearly returning outbreaks, on some places lasting for months.	-Complete societies depend on these yearly floodings.
Storm	-During storm conditions the wind takes the most part, the previous fallen rain is swept up into the air over and over again.	-Surface test not examined while it is reported missing in action. (Blown away?)
Hmm	-Additional use of eyebrows, for adults only(?)!	-They work as rain guidances to keep your eyes dry.
Ice rain	-Rain falling in temperatures just above freezing does hurt the face and seems to soak everything in an instant.	-Depending on previous temperatures surfaces will get wet like with outbreaks, the icy water forms a half frozen mixture with previous fallen snow, appears to contain snowflakes inside the drops on clean surface or forms a layer of ice if surface temperatures are below freezing.
Summer Hail	-Mostly created during a thunder storm, can be just funny when it lasts short and the temperatures do not drop too far during the event.	-If the air and surface temperature was below freezing the small grains will dance and form heaps creating ice walls in an instant. The size can vary from sand grains to head size. No imagination is needed you should take heavy shelter if the latter come falling down.
Winter Hail	-Sometimes created by very cold layers of air close to the ground. Not too big raindrops freeze again in this layer	-This hail will give a mostly more gentle but slippery effect then thunder hail.
Winter hail storm	-The very cold layers of air close to the ground are in rapid movement. Freezing raindrops will be very small as the drops of rain are blown appart by the wind.	-This hail will give nice rigs and little heaps mostly alongside of the path. If it has been snowing previously then the hail will probably stick in the layer of snow creating a slippery crust upon the snow.
First snow	-Slow falling snow whith temperatures just below freezing, the humidity has to be relatively high and the wind has to have a low speed this will create a sticky kind of snow excellent for building snowmans and snowballs. You only have to touch fresh snow with another piece of snow to make it stick together.	-The snowflakes will be big feather structured and already clinging together in the air while slowly falling down. Great fun for kids as they can eat the water ice by catching the snowflakes as they fall in their mouth. Besides eating snow, looking up will dazzle everyone as the earth seems to move up instead of the snow falling down.
Winter snow	-Everything is already covered with snow but it keeps falling down, you have to clean the pavement again. The heaps of dirty snow along the road suggest you should find another way to get rid of the increasing amount of white mass. This snow will be less sticky as the temperature is below freezing for a while now.	-The snowflakes are still more or less feather shaped but have less tendency to grow during their long way down.
Dry snow	-When temperatures far below freezing the air humidity is low, this snow does not stick anymore. The dendrites are evaporated by the time the snowflakes comes down to the ground.	-Leaving rather fast falling grainy snow particles with not much of a distictive shape.
Blowing snow	-With temperatures far enough below freezing, the already fallen snow is picked up by the wind.	-The wind will take up the snow over and over again to drop it in big layers on calm places. These calm places seem to be located in access gates and against doors.
Snow storm	-Lots of snow is falling down at wind speeds under dry circumstances not particulary annoying.	-The sticky snow covers every opening and window. Due to the sideways growing piles on roofs and trees this will give some spectacular effects.
Blizzard	-Loads of snow are falling and the wind is blowing the flakes horizontal. At sufficiently low temperatures the wind also picks up lots of snow from the ground. By bumping into each other he snowflakes are grainded into small particles.	-The little snowflakes tend to creep into every opening, completely solidifying shrubberies into snow mountains and cars into white blobs spread alongside the street.