Reply to thread

Message: <blockquote data-quote="Edena_of_Neith" data-source="post: 3618694" data-attributes="member: 2020">Thus, you don't need weather tables.  You can simply declare to yourself:  - A warm front has pushed through the area, or:  - A cold front has pushed through the area.  Consider these additional things:  The jet stream, 5 miles high, roars along at hurricane force, is 100 miles wide or wider, and flows around the entire planet.  It writhes and coils and alters it's course like a snake trying to slither across pavement.  Sometimes the jet stream will go way north in a curve, and that's known as a ridge.  Sometimes the jet stream will go way south in a curve, and that's known as a trough.  * As a general rule, it is always colder north of where the jet stream happens to be at the moment, regardless of any other factors. *  I said the Temperate Zone got Someone Else's Climate.  To the north is the subarctic and the arctic, and the cold air over those regions comes south.  To the south are the tropics and subtropics, and warm air over those regions comes north.  In the winter, the cold air is colder and the warm air less warm, and in the summer the cold air is less cold and the warm air is warmer, but the two great regions of air - cold and warm - are always there.  Caught between them, the jet stream writhes and twists and bows, creating ridges and troughs (and thus heat waves and cold waves), with warm air masses (led by warm fronts) and cold air masses (led by cold fronts) following each other in mad succession, like armies of dragons fighting in a constant running battle around and around the globe, the war never ending (this mad succession of air masses would do credit to Lord Foul's Sunbane, if you've read the books of Stephen Donaldson.)  Sometimes, the jet stream is blowing one way (from west to east), cold air is coming from the northwest towards the southeast, and warm air is roaring from the southwest to northeast.  The spring sun is shining down strongly, producing intense warm updrafts.  The result is that calamnity we know as the tornado.  All those winds blowing in different directions at different altitudes start a thunderstorm cloud rotating, and then Bad Things happen.  Add in a chinook effect - strong drafts of warm dry air roaring down the slopes of a mountain range, the chinook blast crashing into the mess of conflicting winds I just described, and you have a Tornado Alley.  Such an area has mass outbreaks of tornadoes, with tornadoes possible every month of the year.  If a cold front is passing over a desert area, the strong surface winds behind the cold front often produce sandstorms.  If cold air is blowing over warm lakes, it produces the Lake Effect:  clouds downwind of the lake, along with rain ... or ungodly amounts of snow in the winter.  If there is a mountain range, it tends to rain on the windward side and produce temperate rainforests, while on the leeward side you have a desert.  If you have a deep valley amidst mountains on all sides, air coming down into that valley can compress and warm and produce astonishing heat.  Or if there is moisture, icestorms as the air coming over the mountains is warm, but cold air is trapped down in the valley (during the cold months.)  Or fog in the winter, as frost grips the valley during long winter nights.    If your setting is rich in mountain ranges - as the Forgotten Realms region of Faerun is - you could have drastic changes in the climate from one local area to another, due to the effect of the mountains.  The jet stream still roars overhead, high in the sky, but the mountains lower down mess up the climate in a big way for the locals.</blockquote>

Verification