I was able to get this to work and it filled a need for the low disk space MB. Here is what my .ps1 script looks like that I run with the task scheduler: (run power shell in the task with the full path, then use the path\script for the parameter)

$rootMS=”"

Add-PSSnapin “Microsoft.EnterpriseManagement.OperationsManager.Client” -ErrorVariable errSnapin;
Set-Location “OperationsManagerMonitoring::” -ErrorVariable errSnapin;
new-managementGroupConnection -ConnectionString:$rootMS -ErrorVariable errSnapin;
set-location $rootMS -ErrorVariable errSnapin;

$oldAlerts = Get-Alert | Where-Object {($_.LastModified -ge [DateTime]::Now.AddMinutes(-30)) -and ($_.ResolutionState -eq 0) -and ($_.Name -eq “Logical Disk Free Space in MBytes is low”)}
ForEach($alert in $oldAlerts) {
$alert.Update(“”)}

When I run the .PS1 file it comes with an error:

Connot convert value “\myserver\root\cimv2:win32_process” to type “sytem.management.managementcalss”. Error: “the RPC server is unavailable. ” at C:\scripts\soundalarm.ps1:100 char:23

But the server is Up and I can ping it from the server.

THANKs!!