Hazards

The Convection System

The terminator, the line that separates day from night, moves back and forth throughout the year and bring with it seasonal shifts in temperature and light levels. It also brings thunderstorms, strong winds and rain.

As the air warms up under the hot subsolar sunlight, it rises and expands. The opposite is true in the antisolar darkness of the night. This results in a circulation of heat exchange, where a warm stream of high air travels to the night, and a low cold stream travels towards the day. The effect is that the temperature of the two hemispheres gets equalized somewhat, and even if the sunscorched subsolar desert or the bonechilling midnight are still beyond uninhabitable for most, they are not as bad as they would have been without the convection systems.

Temperature

Category	Temperature	Fatigue	Damage
Incredible cold	below -60°C	2 hours	Moderate cold every minute
Extreme cold	-59°C to -30°C	4 hours	Minor cold 10 minutes
Severe cold	-29°C to -10°C	4 hours	Minor cold every hour
Mild cold	-9°C to 0°C	4 hours	None
Normal	0°C to 34°C	8 hours	None
Mild heat	35°C to 39°C	4 hours	None
Severe heat	40° C to 45°C	4 hours	Minor fire every hour
Extreme heat	46° C to 60°C	4 hours	Minor fire 10 minutes
Incredible heat	above 60°C	2 hours	Moderate fire every minute

The seasons caused by the 30° oblequity is tied with natural temperature variance. The subsolar spot moves, and the ring of temperate climate moves with it.

Orn's most populated regions vary within the normal range, depending on both location and time of year. They are mainly subtropic, with tundra nightward, and bordering on tropic in the deltas most towards the day in the Verdant Veil. During winter there are dips into mild cold, as weather patterns fluctuates, and in the summer there are likewise periods of mild heat, even if these heated periods are rather rare.

The sparcely populated tundra reach freezing temperatures of severe cold at times, but mostly fluctuates between mild cold and the lower edge of normal. During winter it usually never above 0°C, and even in summer the permafrost keeps things rather cold.

Weather phenomenons

The weather fluctuates within the boundries one might expect. At times the sky is clear, letting the sun shine unimpeded, but there is usually some degree of cloud cover.

Usual hazardous weather phenomenons are:

Ashfall

Beyond the nightwards mountains of Mendaris, there are several active vulcanos. These spew ash and smoke from time to time, though seldom at an intensity or a duration that seriously inconvenience those exposed to it. These periods are often referred to as ashfall. They bring very dark clouds, and a foul rain most try to avoid being exposure to. Depending on the severity, it may lower the light provided by the sun by a step requiring lamps for normal light levels.

Thunderstorms

At times, the clash and friction between the cold and warm fronts of the night and day result in the violent release of lightning which is usually accompanied by hail or heavy rain. This type of weather is more common during the winter seasons, but is not unheard of during the summer.

Rainstorms

This fairly common phenomenon brings large amounts of water to the subtropic regions, and at times as far sunwards as the tropics. It darkens the sky to a greater degree than other heavy cloud cover.

Mist

Caused by the meeting of warm and cold air when the resultant air can not hold the humidity. This is a fairly common phenomenon, but is usually an indicator of changing weather and usually passes in the span of an hour or so.

Altitude

High altitude travel can be extremely fatiguing—and sometimes deadly—to creatures that aren’t used to it. Cold becomes extreme, and the lack of oxygen in the air can wear down even the most hardy of warriors.

Acclimated Characters

Creatures accustomed to high altitude generally fare better than lowlanders.

Any creature with an Environment entry that includes mountains is considered native to the area and acclimated to the high altitude.

Characters can also acclimate themselves by living at high altitude for 30 bells. Characters who spend more than 60 bells away from the mountains must reacclimate themselves when they return. Undead, constructs, and other creatures that do not breathe are immune to altitude effects.

Altitude Zones

In general, mountains present three possible altitude bands: low pass, low peak/high pass, and high peak.

Low Pass

(lower than 5,000 feet):

Most travel in low mountains takes place in low passes, a zone consisting largely of alpine meadows and forests. Travelers might find the going difficult (which is reflected in the movement modifiers for traveling through mountains), but the altitude itself has no game effect.

Low Peak or High Pass

(5,000 to 15,000 feet):

Ascending to the highest slopes of low mountains, or most normal travel through high mountains, falls into this category. All non-acclimated creatures labor to breathe in the thin air at this altitude. Characters must succeed on a Fortitude save each hour (DC 15, +1 per previous check) or be fatigued. The fatigue ends when the character descends to an altitude with more air. Acclimated characters do not have to attempt the Fortitude save.

High Peak

(more than 15,000 feet):

The highest mountains exceed 15,000 feet in height. At these elevations, creatures are subject to both high altitude fatigue (as described above) and altitude sickness, whether or not they’re acclimated to high altitudes. Altitude sickness represents long-term oxygen deprivation, and affects mental and physical ability scores. After each 6-hour period a character spends at an altitude of over 15,000 feet, he must succeed on a Fortitude save (DC 15, +1 per previous check) or take 1 point of damage to all ability scores. Creatures acclimated to high altitude receive a +4 competence bonus on their saving throws to resist high altitude effects and altitude sickness, but eventually even seasoned mountaineers must abandon these dangerous elevations.

External links

• Hadley circulation