This article is about the group events. For the DLC, see Harrowstorm.
Harrowstorms are "giant supernatural confluxes" which plague Western Skyrim and the Reach. Much like Dark Anchors, Abyssal Geysers and Dragonscours, Harrowstorms function as group events, where a number of players must work together to shut the Harrowstorm ritual down.
Only one Harrowstorm per zone can spawn at once, and the order is selected randomly; the same Harrowstorm can spawn multiple times in a row. Western Skyrim, Blackreach: Greymoor Caverns, and the Reach are on separate spawn cycles. You can tell if a Harrowstorm has recently spawned as it will lack the camp in the center; otherwise, you will meet three travelers gathered round a fire. These people will be killed when the storm spawns. You can tell when a Harrowstorm is about to begin by the red mist that begins to gather, and once the storm begins it can be seen from far distances.
You must destroy the three Witch Pikes in the midst of the storm; each pike draws in Lost Souls, which will heal the pike if they are allowed to reach it. You will need to destroy all three pikes as quickly as possible to prevent the reliquary at the center of the storm from summoning ever greater monsters. In addition to the high number of enemies, the storm above can cause AoE damage via red lightning strikes, sometimes resulting in instantaneous death if you aren't looking where you're standing. Once all three pikes are destroyed, the boss will spawn in the center of the ritual site. Once the boss is defeated, a pile of "Reliquary Remnants" will appear in the center and can be searched for loot, but be careful as you approach as the storm will discharge a few more lightning strikes before it dissipates. Matron Jagiska taunts you throughout the fight.
- Black Morass Ritual Site — A Harrowstorm ritual location west-northwest of Morthal.
- Chilblain Peak Ritual Site — A Harrowstorm ritual location southwest of Dragon Bridge.
- Giant's Coast Ritual Site — A Harrowstorm ritual site on the far northwest coast of Western Skyrim.
- Hailstone Valley Ritual Site — A Harrowstorm spawn point east of Morthal in eastern part of Western Skyrim.
- Northern Watch Ritual Site — A Harrowstorm ritual site on the northeast coast of Western Skyrim.
- Old Karth Ritual Site — A Harrowstorm ritual location east of Karthwatch.
- Dwarf's Bane Ritual Site — A Harrowstorm ritual site in Dusktown Cavern.
- Gloomforest Ritual Site — A Harrowstorm ritual site in eastern Blackreach: Greymoor Caverns, near the Lightless Hollow.
- Miner's Lament Ritual Site — A Harrowstorm ritual site in Dusktown Cavern.
- Nightstone Ritual Site — A Harrowstorm ritual site in western Blackreach: Greymoor Caverns, near Dark Moon Grotto.
- Harrowed Haunt Ritual Site — A Harrowstorm ritual location north of Hroldan Ring.
- Ragnvald Ritual Site — A Harrowstorm ritual location northwest of the North Markarth Wayshrine.
- Reachwind Ritual Site — A Harrowstorm ritual location south of Reachwind Depths.
- Witchborne Ritual Site — A Harrowstorm ritual location east of the Black-Moon Clan Camp.
- Halt the Harrowstorms: Help liberate Skyrim from the Icereach Coven's threat by disrupting Harrowstorms.
- Halt the Harrowstorms: Aid Reachfolk in stopping the Gray Host's machinations by distrupting Harrowstorms.
- Gray Host Bloodknight
- Gray Host Wolflord
- Harrowing Reaper
- Harrowstorm Abomination
- Harrowstorm Gargoyle
- Harrowstorm Shrike
A wide variety of items can be looted from the shattered Gray Reliquaries. Notable items include:
- Vile Coagulant, a new alchemy ingredient
- Gray Reliquary Satchels, sacks that contain treasure maps, furnishing patterns and provisioning recipes
- Vampiric Furnishing Recipes
|Alchemical Reagents||Vile Coagulant||Emetic Russula||Fleshfly Larva||Imp Stool||Luminous Russula||Namira's Rot||Nightshade||Spider Egg||Stinkhorn||Violet Coprinus||White Cap|
|Fine Items||Eternal Vigor jewelry||Venomous Smite jewelry||Winter's Respite jewelry||Ancestor Ash||Blood Capsules||Blood-Encrusted Thorn||Blood-Friend's Silken Neck Wrap||Bloodfed Rose||Dragonbone Fang Caps||Fangs of Sacrifice||Ivory Teeth||Kotu Gava Blood Cocktail||Opulent Family Funerary Jar||Ornate Skull Goblet||Twisted Root Vial|
|Superior Items||Gray Reliquary Satchel||Vampiric Furnishing Recipes||Eternal Vigor jewelry||Venomous Smite jewelry||Winter's Respite jewelry||Breton Funeral Urn||Crimson Rose Walking Stick||Feast of Souls Miniature Painting||Filigreed Ash Urn With Portable Altar||Jeweled Bloodletter||Ritual Daedra Skull||Vampire Clan Lineage||Vampiric Hourglass||Vial of Vampire Blood|
|Epic Items||Blood Amber||Eternal Vigor jewelry||Venomous Smite jewelry||Winter's Respite jewelry|