As one who has both suggested and supported this idea in the past, I strongly support.
Weather type:
duration in in-game time
frequency per 15 provinces per day unless otherwise noted
provinces effected
effect on province
max unit damage
movement
other info
Thunderstorm:
duration: 10-30 min
frequency: 20%
provinces effected: 1
province effect: minor damage to buildings
max unit damage: air-10%
movement: none
Supercell thunderstorm:
duration: 30 min - 2 hr
frequency: 5% of thunderstorms (real life stats)
provinces effected: 1-3
province effect: slightly less minor damage to buildings and morale drop of 5*
max unit damage: inf-10% arm-5% air-50%*
movement: none
* storm has a 33% chance of spawning a tornado in one province which can destroy buildings and units or do nothing depending on strength
Blizzard:
duration: 1-2 hr
frequency: 10% (mountains only)
provinces effected: 1
province effect: slows production
max unit damage: none
movement: none
slows land units, air units are grounded
Hurricane:
duration: 3-6 days
frequency: 5-10 times per game
provinces effected: ?
province effect: damaged or destroyed buildings and morale drop of 30-50
max unit damage: destroyed
movement: 20-40 km/h, starts at sea and can go on land
Storm shelters could be built to protect units and morale, ships could be docked at storm shelter provinces.
And a weather tab could be added, showing provinces most likely to have storms in the next 2 days, and alerts of hurricanes 3-5 days in advance. However these could be completely wrong.


