Added blast radius to outage types

Author: lukeknep

docs/cloud/rto-rpo.mdx

@@ -34,6 +34,8 @@ An [Availability Zone](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using
 
 Historically, AZ outages are the most common type of outage in the cloud, and Temporal Cloud has weathered many of them transparently to its customers.
 
+**Blast Radius:** A single Availability Zone within a single cloud region. Because every Namespace's components are spread across at least three AZs, the blast radius to Temporal Cloud users is typically zero — Namespaces stay operational with little to no downtime. However, the outage will take out any Workers the user is running in that AZ. We recommend spreading Workers across multiple AZs to mitigate this.
+
 **Temporal Cloud feature to mitigate this outage:** Every Namespace is automatically spread across at least three Availability Zones, and any Namespace can handle a single AZ failure without disruption to end-user Temporal operations. [High Availability](/cloud/high-availability) features are _not_ required to keep Temporal Cloud operations running through an AZ outage.
 
 If two AZs fail simultaneously, Temporal Cloud treats the event as a [Cloud Region outage](#cloud-region-outage). In that case, Namespaces in the region may be impacted, including those using Same-region Replication (in Preview).
@@ -57,6 +59,8 @@ Temporal Cloud runs on a [cell architecture](https://docs.aws.amazon.com/wellarc
 
 **Example causes:** failure of a sub-component within the cell (for example, an individual database becoming unavailable) or a software bug introduced in a new deploy to the cell.
 
+**Blast Radius:** One cell--and the Namespaces within that cell--within a single region. Even though your Workers will remain healthy, they will not be able to process Workflows because the Namespace is down.
+
 **Temporal Cloud feature to mitigate this outage:** [Multi-region Replication](/cloud/high-availability) (GA) and [Multi-cloud Replication](/cloud/high-availability) (GA) replicate a Namespace into another cell in a different region or different cloud provider. [Same-region Replication](/cloud/high-availability) (Preview) replicates a Namespace into another cell in the same region. With any of these features enabled, an outage that disrupts a single cell can be mitigated by failing the Namespace over to its replica.
 
 Cell-level disruptions occur from time to time, and Temporal's replication and failover tooling has restored affected Namespaces in real-world incidents.
@@ -76,6 +80,8 @@ A cloud region as a whole can become degraded, with effects that span beyond any
 
 **Example causes:** failure of a key cloud service in the region (for example, the cloud provider's DNS resolver) causing cascading failures, two or more Availability Zones failing simultaneously, or network partitions between the region and other regions.
 
+**Blast Radius:** All Namespaces and Workers within a single cloud region are potentially affected. Namespaces and Workers in other regions of the same cloud — and in other clouds — are unaffected.
+
 **Temporal Cloud feature to mitigate this outage:** [Multi-region Replication](/cloud/high-availability) and [Multi-cloud Replication](/cloud/high-availability) place the replica outside the affected region, so a Namespace can fail over and continue serving Workflows. Same-region Replication does not protect against a Cloud Region outage, since the replica resides in the same region.
 
 Regional outages are less common than cell or AZ outages, but they happen. During the [AWS us-east-1 incident on October 20, 2025](https://temporal.io/blog/how-devs-kept-running-during-the-aws-us-east-1-oct-20-2025), Temporal Cloud's regional failover kept customer Namespaces running.
@@ -95,6 +101,8 @@ On rare occasions, an issue affects most or all regions of a single cloud provid
 
 **Example causes:** a software bug rolled out to every region of a cloud provider that triggers cascading failures across the provider's infrastructure.
 
+**Blast Radius:** Most or all regions of a single cloud provider. Every Namespace and every Worker hosted in that cloud is potentially affected.
+
 **Temporal Cloud feature to mitigate this outage:** [Multi-cloud Replication](/cloud/high-availability) places the replica in a different cloud provider entirely, so the Namespace can fail over even when an entire cloud provider goes down.
 
 Cloud-wide outages are the rarest category, but they [have occurred](https://status.cloud.google.com/incidents/ow5i3PPK96RduMcb1SsW). Multi-cloud Replication is designed to keep Namespaces running through such events.