Weather

Experience the first truly planetary, physics-driven weather system in a game—where every cloud, storm front and fog bank is born of real-world thermodynamics, moisture advection and atmospheric circulation. We don’t just simulate weather, we simulate a planet’s climate.

Overview

Vieneo is a tidally locked exomoon with a dense, high-pressure atmosphere and perpetual cloud cover, resulting in a uniquely complex and dynamic climate. The weather simulation in Rise: The Vieneo Province has evolved into a sophisticated planetary model with dynamic interactions between temperature, humidity, convection, terrain, wind, and time of day. Weather conditions are calculated per-location using global environmental maps and physical models.

Atmospheric Characteristics

• Atmospheric Pressure: ~2.6 bar at sea level
• Diurnal Cycle: 14.43-hour day
• Peak Temperature Lag: ~3.5 hours after local solar noon (≈87.3° longitude offset)
• Midday Temperature Rise: Typically less than 10°C due to dense cloud cover

Measured Global Averages

• Turbulence: Avg 0.358 (scale 0–1)
  • Comparable to light-to-moderate convective activity on Earth. Peak turbulence occurs near equatorial storm zones, with transient strong updrafts.
• Relative Humidity (RH): Avg 58.2%
  • Min: 18.3%, Max: 100%
• Precipitation:
  • Avg: 0.076 mm/hr
  • Max: 16 mm/hr (severe storm cells)
  • Scale runs from 2–16, aligning with mm/hr intensity
• Wind Speeds:
  • Avg: 4.71 m/s (~10.5 mph)
  • Max observed: 56.4 m/s (~126 mph)
  • Area with >20 m/s winds: 0.4%
• Visibility:
  • Avg: 40.1 km
  • <1 km: 2.0%
  • <5 km: 3.5%
  • <10 km: 3.6%
  • >30 km: 94.5%

Flight Rules Classification (Ceiling AGL and Visibility)

• Instrument Flight Rules (IFR): 7.4%
• Marginal VFR (MVFR): 47.6%
• Average Ceiling: 1.16 km AGL (~3,800 ft)

Core Models Used

• Vapor Layer: Relative humidity and dew point derivation
• Temperature Deviation Layer: Surface temperature variation based on season and time
• Convection Layer: Storm potential and turbulence
• Wind Speed Layer: Baseline surface and aloft wind speeds
• Wind Direction Layer: Orographic and directional wind effects
• Elevation Map: Terrain height for ceiling and visibility calculations

Diurnal and Seasonal Effects

• Temperature modulates with solar angle
• Seasonal subsolar movement causes ±10–12°C swings

Temperature and Dew Point

• Range: -55°C to +47°C
• Dew point derived from vapor map via exponential approximation
• Max dew point spread: ~21.5°C

Relative Humidity

• Computed using Magnus-Tetens formula:

RH = exp((17.625 × Td)/(243.04 + Td)) / exp((17.625 × T)/(243.04 + T))

Turbulence (Storm Potential)

• Simulates jet stream drift via Rossby wave patterns
• Daily peak near midday
• Affects gusts, cloud formation, and precipitation
• More widespread than on Earth due to dense atmosphere and solar heating dynamics

Cloud forms above the deck

The client uses the live global convection map to vary the height allowed for rounded formations above Vieneo's widespread cloud deck. With the normal 10 km MSL deck, quiet areas have shallow cloud relief, while developed formations can extend toward the 22 km MSL upper limit. Large connected formations contain smaller billows, with finer detail shaped by wind direction. Procedural grouping and erosion determine the actual visible tops.

Grayscale 0 is the quiet endpoint and 255 is maximum convection. The additional height allowance follows the normalized value raised to the power 0.75: 127 allows about 59.3% of the maximum local increase, 192 about 80.8%, and 255 the full increase. This is an allowance above the quiet cloud envelope, not a percentage of the cloud's total altitude. Moderate convection can produce developed billows while quieter regions remain relatively flat.

This client visual approximation does not change the server's weather or Vieneo's atmospheric definitions; it is not a calculation of buoyancy or cloud microphysics. Cloud lightning continues to use the live convection map independently of this height curve. The in-world simulator retains its baseline cloud appearance.

Precipitation

• Triggered when RH × Turbulence > 0.44 below ~6.5 km altitude
• Intensity scaled 2–16 (in mm/hr)
• Can cool surface by up to 6°C
• Planetary precip coverage targets ~7.5%

Wind Modeling

• Layered up to 63 km altitude
• Gusts enhanced by turbulence
• Strongest winds seen in mid-latitude and equatorial storm belts

Orographic Lifting and Visibility

• Visibility reduced when upwind terrain is higher and RH is high
• Modulated by dew point spread and wind speed

Visibility Calculations

• Fog: Triggered by small T–Td delta and elevated terrain
• Precipitation visibility effects:
  • Light (2–6): ~2 km visibility
  • Moderate (10–12): ~1–5 km
  • Heavy (>12): ~0.5–4.5 km
• Wind Mixing:
  • 5–15 m/s: improves visibility
  • >20 m/s: can cause haze and dust
• Final Clamp: Visibility range: 0.05–25 km

Ceiling Calculations

• Formula: (T - Td) × 0.12192 km/°C
• Adjusted for terrain height difference
• Minimum ceiling enforced over Deois
• If ceiling <150 m AGL below midcloud, visibility is reduced

Sanity Checks and Constraints

• Fog forces min precip to 2.0
• Syncs ceiling and visibility to avoid logical conflicts

Notes to Pilots

• Cloud Bases: Widespread stratiform decks, often 1–2 km AGL
• Low Visibility Zones: Mountainous or humid regions prone to IFR
• Storm Zones: Mostly near equator or mid-latitudes
• Winds Aloft: Jet-stream equivalents exist—expect wind shear
• Turbulence: More persistent than Earth; strong convection common

Cloud lightning

Above the clouds, lightning appears as brief illumination scattered through existing cloud moisture. Sources follow the occupied cloud bodies, including raised convective billows. A discharge can illuminate one to three connected sections in sequence, with irregular repeat pulses; exposed bolts are not required to see this orbital effect. Look down toward active storms, preferably at night or twilight. Flashes have less contrast against directly sunlit clouds and remain easier to see in darker cloud regions. This depends on the illumination at the clouds, not simply whether the ship is on the day or night side. The irregular glow is a client rendering approximation, not a calculation of electrical charge layers or Vieneo aerosol optics.

The natural client-local generator targets about 100 events per second across the entire planet, weighted strongly toward higher live convection values. This is not 100 visible flashes per second from one ship: the horizon, camera direction, weather distribution and cloud obscuration reduce what is visible. Chained sections and repeat pulses belong to one event. The convection map and cloud geometry are not altered by lightning.

Lightning is disabled in the in-world simulator, including transient illumination on entering it. Administrators can use 000COMMANDCLOUDBOLT1 for a 30-real-second orbital visibility test and 000COMMANDCLOUDBOLT0 to stop it. This forces nearby cloud events without changing weather or the natural event stream, and produces no server event, thunder or damage. See Special Commands for requirements and reset conditions.

Summary of Key Ranges

Parameter	Min	Max
Temperature (Surface)	-55°C	+47°C
Dew Point Spread	0°C	~21.5°C
Precipitation	0 mm/hr	16.0 mm/hr
Wind Speed	~0 m/s	~60 m/s
Visibility	0.05 km	25.0 km
Ceiling (AGL)	0.0 km	~5.0+ km

Imagery

Global weather radar map showing precipitation clusters

See Also

• Atmosphere
• Player Portal
• Weather Simulation Realism Analysis
• Doppler Radar

Notes

The system is designed for future upgrades including airborne radar, storm particles, and localized weather patterns. Orographic effects and fog are computed dynamically using directional wind sampling.