In the depths of last week’s deep freeze, with all its worries of frozen pipes and heating oil shortages, you may have wished for warm weather. Now that it’s on its way, you might think again.
With temperatures climbing into the 50s on Thursday and higher on Friday, and pelting rains expected into the weekend, a new headache is coming: floods.
Maybe not the storm-surge flooding that hit coastal areas during last week’s “bomb cyclone,” but a deep soaking for basements and streets, especially in low-lying places, and anything near snow-clogged storm drains and catch basins.
“That’s problem No. 1,” said Eleanor Vallier-Talbot, a meteorologist with the National Weather Service office in Taunton. “Then the next problem is going to be the rivers. Right now the rivers are frozen up, and the rain water is going to get in there and cause the rivers to rise, which may cause the ice to break up and create ice jams at places like bridges, which could cause the water to back up behind it. Then, when the ice jam breaks, it could cause flooding down river.”
The Boston Water and Sewer Commission has been using the label #helpthemelt on social media to encourage people to shovel out storm drains.
Who should be concerned? “Anybody who has flooding in their basements in the spring,” said meteorologist David Epstein. “If you’re somebody with a sump pump in your basement, you should check it.”
The amount of moisture expected from the rain, by itself, is no big deal for the season, Epstein said, but the mild temperatures will unlock 1 to 3 inches of additional water currently trapped in snowbanks. And while everyone wants to see the rapid demise of the snow, it’s too much when the ground remains frozen and unable to absorb both Frosty’s remains and the fresh rain.
“The water has nowhere to go,” Epstein said. “[Any flooding] is going to be during the heaviest rain. You’re not talking flooding that’s going to last for hours; it’s for a short period of time until that rain can drain itself.”
Flood-prone areas like Storrow Drive and parts of Route 9 and the Mass. Pike might be affected Friday and Saturday, Epstein said.
Crews from the state Department of Conservation and Recreation, which oversees Storrow Drive, have been clearing catch basins of debris and ice this week throughout Greater Boston. They’re also making sure the Charles River water pumps are in good shape, adjusting the river’s water levels ahead of the rain and thaw, according to a spokesman. Crews will also continue to monitor flood-prone Morrissey Boulevard in Dorchester, preparing for potential road closures.
It is a lot to take for a region that is still recovering from a brutally long stretch of cold and the haymaker of a storm that arrived last Thursday.
“We’ve had floods before, but that was the biggest. The waters were higher than we ever thought they could be,” said Tobin Dominick, the co-owner of Cape Ann’s Marina Resort in Gloucester, which was swamped by last week’s storm.
The marina sits just across from Gloucester High School, which made headlines last week when ocean water washed hundreds of yards across athletic fields from the Annisquam River, flooding the school parking lot and damaging some 60 cars.
Dominick said workers are now clearing drains and making sure the snowmelt and rain have a place to go.
That prescription, officials from Boston and elsewhere say, is the key to weathering what’s about to happen: You must clear a path for the coming water.
Towns including Winthrop have issued weather alerts advising residents to shovel remaining snow around downspouts and carve a path to carry the runoff away from their homes to prevent basement flooding.
In East Boston, resident Margaret Farmer said she is concerned about flooding in certain parts of the neighborhood, including along Princeton Street in Eagle Square.
“I love snow, but the thing about snow is you want it to melt slowly so that the ground can absorb it,” Farmer said. “Everything is going to melt all at once, and with the rain coming down we’re guaranteed to have flooding, especially during high tide.”
When all the work to prepare for the coming waters is done — fear not — there will be a new problem to contend with, experts warn. Everything’s going to freeze again. Remember ice dams? Forecasters say they’ll return with a vengeance when freezing temperatures return this weekend and mix with any wet snowpack that remains on roofs.
Rick Stoeckel, of Tonry Insurance Group in Quincy, said other than flood damage, the most common claim his office gets this time of year is for ice dam damage. Any snow that hasn’t melted off roofs should be removed before the freeze sets in, Stoeckel said. Experts advise using an extendable ice rake to clear the snow safely, without having to go on the roof, which can be quite dangerous in these conditions.
Despite all this, there is good news to consider. By next weekend, we will have completed the first month of winter. There are only two more to go.Billy Baker can be reached at firstname.lastname@example.org. Follow him on Twitter @billy_baker. Katheleen Conti can be reached at email@example.com. Follow her on Twitter @GlobeKConti.