The Maine Public Utilities Commission has concluded that Central Maine Power and Emera Maine responded “reasonably” to an intense rain and wind storm last October that led to record blackouts in much of the state, based on the best available weather forecasts at the time.

The decision, which came in an unanimous vote Tuesday by the three commissioners, ends an investigation into whether the state’s utilities took the right steps to plan for the Oct. 29 storm and restore service after it had passed. Roughly 467,000 CMP customers and 90,000 Emera customers lost power; small numbers were out for more than a week.

Last August, the PUC’s staff issued a report that said the response was reasonable, but that both companies failed to keep customers well informed about outages and efforts to restore power. Each company has been ordered to file a report by Dec. 1, outlining specific steps to improve the accuracy of and customer access to its outage and restoration reporting.

Tuesday’s action followed a fact-finding probe that included examining storm reports and posing questions to CMP and Emera.

The PUC wanted to assess whether CMP and Emera adequately prepared for the storm, by monitoring weather forecasts and securing additional repair crews from in and out of state, when it became clear the storm was likely to cause heavy damage. It also examined how the two utilities responded to the damage, including whether their outage data and estimates of when power would be restored were accurate and readily accessible to customers.

At Tuesday’s deliberations, PUC Chairman Mark Vannoy noted that both companies had made storm preparations and positioned restoration crews with a goal of getting lights back on within 24 to 48 hours. But the weather forecasts that guided those plans didn’t predict wind gusts that turned out to much higher than expected.

Utilities across the country struggle with this sort of cost-benefit risk analysis, Vannoy added. Expenses begin mounting the minute utilities pre-position crews ahead of a storm, or call for assistance from other power companies and contractors.

The storm led to the highest number of outages in CMP’s history. Since then, CMP has taken steps to add more-robust storage and generators to its network of digital smart meters. A large percentage of the meters failed to accurately convey outage data during the storm, after batteries powering the network died. At the same time, many customers complained that CMP’s phone- and web-based outage reporting systems provided inconsistent or false information following the storm.

CMP and its parent company, Avangrid, also want to get approval from the PUC to harden the distribution system against future storms, with strong poles and wires less vulnerable to tree damage. The company is expected to release details of its plans this fall, which will include the impact on electric customer bills.

Following the PUC’s deliberations, CMP said it agreed with the decision and said the findings were in line with its own assessments, filed last winter with the commission. In addition to resiliency measures, CMP has been meeting with county and state emergency management personnel, municipal officials, and telecommunications companies to improve coordination during major storm events. It’s also reviewing improvements on how it communicates the estimated times for restoring service.

Beyond storm prepartion, CMP remains under fire on several other fronts.

Stunned by electric bills last winter that were as much as four times the norm, hundreds of people filed complaints with the PUC and the Public Advocate’s office. That has led to dual PUC probes into billing software and other technical issues, as well as a pending class action lawsuit by disgruntled customers.

In mid-July, the PUC voted to launch an investigation into whether CMP had been overcharging its customers.