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

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

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

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.