This story was updated at 9:05 p.m.
Tropical Storm Isaias is expected to bring Vermont high winds and heavy rain on Tuesday night, mainly to southern Vermont and the Champlain Valley, as its trajectory shifts west.
Its track has pushed much of the heavy rain to New York, said Worcester-based meteorologist Roger Hill, while western and southern Vermont will see high winds. Flood risks increase to the west.
“It’s interesting because Tropical Storm Isaias is holding its power due to the fact that it’s interacting with a very strong jet stream and a trough that’s off to the west of us,” Hill said. “That’s steering everything, and it’s continuing to push the track just a little bit to the left.”
Forecasters say tropical storm force winds of 50 miles per hour and higher are possible, with the storm entering the state Tuesday afternoon, and predicted to exit the state around midnight.
Meteorologists say that tornadic thunderstorm activity has been seen with this storm as it moves across the mid-Atlantic states early Tuesday.
“We have conditions that would support the spin up of small tornados, small vortices, that would develop out of some of the stronger thunderstorms that move on through,” Hill said. “There’s not a lot of lightning with these, but there’s been a few reports of damaging winds, mostly to the south of us.”
At about 9 p.m., Vermont power companies were reporting about 20,000 customers without power. Green Mountain Power had 17,060 customers in 80 towns in the dark, with the majority in southern Vermont. Wilmington had 2,940 outages, Brattleboro 2,677 and Dover 1,420. Washington Electric Co-op had almost 1,200 customers without power. Vermont Electric Co-op had just over 800 outages.
Michael Schirling, commissioner of the Department of Public Safety, briefed the public at the Gov. Phil Scott’s press conference Tuesday morning.
“It’s moving pretty swiftly,” he said. “We anticipate, as a result of that westward traffic, there’ll be an increase in wind component to southern Vermont, eastern Vermont, in particular Bennington and Windham counties, based on the current track.”
Hill said wind will likely be most problematic for Vermonters.
“It could produce some power outages, mostly in the higher terrain,” he said. “The worst case scenario is to get some kind of a tornadic thunderstorm in the middle of the night, or at least in the evening during darkness. And there is that possibility, as some of these storms may spin up a kind of a real brief, weak tornado.”
Hill encourages residents to watch information released by the National Oceanic and Atmospheric Administration and keep a close eye on local flood warnings.
Towns around Vermont have been preparing for the storm’s arrival. Officials met Tuesday morning in Bennington, according to Selectboard Chair Donald Campbell, and will take “whatever measures may be necessary.”
Departments in Rutland have been monitoring water infrastructure to make sure it’s ready for the storm’s impact.
Matt Whitcomb, president of Rutland’s Board of Aldermen and acting mayor, said city personnel are on stand-by. Officials have inspected local dams, cleared storm drains, and reviewed flood-prone areas.
“One of the things that Rutland did well was learn from the damage caused by Irene,” Whitcomb wrote in an email. “Over the past decade there has been work done to address areas prone to flooding. One particular area was Dunklee Pond Dam, which has been removed and we have a much more controlled flow of water during larger storms.”
Green Mountain Power has alerted its customers to prepare for the winds, which brings the stronger possibility of statewide impacts including outages due to downed trees and power lines, though the full impacts are difficult to predict with the continued changing track of the storm.
Customers should be prepared for outages and stay away from any downed trees or lines, GMP said in a release. GMP’s storm preparation and safety tips, sign up options for text alerts and outage reporting tools are listed on its website.
The company noted that crews are following extra health and safety precautions during the Covid-19 pandemic, so GMP is encouraging customers to maintain a distance of at least 6 feet from crews, following CDC social distancing guidelines.
“We want customers across Vermont to be alert, and prepared for outages,” said Mike Burke, chief of field operations for GMP.
