Shivas weather holder

code/__DEFINES/weather.dm

@@ -3,6 +3,7 @@
 
 // Probabilities of a weather event occurring each tick, per map
 #define PROB_WEATHER_SOROKYNE 100 //Map specific defines go here.
+#define PROB_WEATHER_SHIVAS_SNOWBALL 80
 #define PROB_WEATHER_BIG_RED 30
 #define PROB_WEATHER_LV624 30
 #define PROB_WEATHER_NEW_VARADERO 100

code/datums/weather/weather_map_holders/shivas_snowball.dm

@@ -0,0 +1,19 @@
+//// Shivas's map holder
+
+/datum/weather_ss_map_holder/shivas_snowball
+	name = "Shivas Snowball Map Holder"
+
+	min_time_between_events = 20 MINUTES
+	no_weather_turf_icon_state = "strata_clearsky"
+
+	potential_weather_events = list(
+		/datum/weather_event/snow
+	)
+
+/datum/weather_ss_map_holder/shivas_snowball/should_affect_area(area/A)
+	return !CEILING_IS_PROTECTED(A.ceiling, CEILING_GLASS)
+
+/datum/weather_ss_map_holder/shivas_snowball/should_start_event()
+	if (prob(PROB_WEATHER_SHIVAS_SNOWBALL))
+		return TRUE
+	return FALSE

code/game/area/shiva.dm

@@ -159,7 +159,7 @@
 /area/shiva/interior/caves
 	name = "Shiva's Snowball - Caves"
 	icon_state = "caves0"
-	ceiling = CEILING_UNDERGROUND_METAL_BLOCK_CAS
+	ceiling = CEILING_UNDERGROUND_BLOCK_CAS
 
 /area/shiva/interior/caves/right_spiders
 	name = "Shiva's Snowball - Forgotten Passage"

colonialmarines.dme

@@ -663,6 +663,7 @@
 #include "code\datums\weather\weather_map_holders\lv522_chances_claim.dm"
 #include "code\datums\weather\weather_map_holders\lv624.dm"
 #include "code\datums\weather\weather_map_holders\new_varadero.dm"
+#include "code\datums\weather\weather_map_holders\shivas_snowball.dm"
 #include "code\datums\weather\weather_map_holders\sorokyne.dm"
 #include "code\datums\xeno_shields\xeno_shield.dm"
 #include "code\datums\xeno_shields\shield_types\crusher_shield.dm"

maps/shivas_snowball.json

@@ -6,6 +6,7 @@
     "environment_traits": {
         "COLD": true
     },
+    "weather_holder": "/datum/weather_ss_map_holder/shivas_snowball",
     "survivor_types": [
         "/datum/equipment_preset/survivor/corporate/shiva",
         "/datum/equipment_preset/survivor/doctor/shiva",