Will Henri Be Another Superstorm Sandy? Here's What the Forecast Says.

U.S.|Henri is improbable to beryllium different Superstorm Sandy. Here’s why.

• Aug. 20, 2021, 2:39 p.m. ET

Adam Sobel is simply a prof and manager of the Initiative connected Extreme Weather and Climate astatine Columbia University. He is an atmospheric idiosyncratic and big of the Deep Convection podcast.

There are immoderate striking similarities betwixt Tropical Storm Henri, which is forecast to go a hurricane earlier making landfall on the Northeast seashore this weekend, and Hurricane Sandy, which devastated parts of New York and New Jersey successful 2012.

At the aforesaid time, determination are immoderate precise important differences that volition astir apt impact the way and interaction of Henri. New York City, successful particular, is not astatine large hazard this time, though immoderate forecast models inactive amusement Henri turning westbound and making landfall there.

There’s a crushed that hurricanes seldom scope New York oregon New England, wherever nary has made landfall successful the 30 years since Hurricane Bob successful 1991. As storms drift north, they get caught up successful the prevailing winds astatine higher latitudes. These winds mostly stroke from westbound to eastbound (unlike tropical winds, which mostly stroke the other way), and propulsion hurricanes retired to sea, distant from the Eastern Seaboard.

Something has to interruption that signifier earlier the Northeast tin get a nonstop hit.

What tin bash that? Either a high-pressure strategy offshore to the eastbound of the storm, oregon a low-pressure strategy approaching from the onshore to the west, oregon both, tin thrust a hurricane northward alternatively than eastward. When those conditions occur, the south-facing parts of the seashore — from Long Island to Cape Cod — go the astir apt landfall area, arsenic it is for Henri.

Similar meteorological situations person been liable for most, if not all, of the hurricane landfalls successful the area, similar the 1938 “Long Island Express” tempest and respective hurricanes successful the 1950s. Those events prompted the gathering of tempest surge barriers successful Stamford, Conn., Providence, R.I., and New Bedford, Mass.

Sandy was an utmost case. An approaching low-pressure strategy was beardown capable to origin Sandy to revolve astir it (and vice versa) arsenic the 2 systems merged. successful what is called the Fujiwhara effect. This process strengthened Sandy and slung it westward, resulting successful the “left hook” that brought the tempest into the New Jersey enactment astatine astir a close angle. No different tempest is known to person done that.

A akin configuration is processing now: An approaching upper-level low-pressure strategy is predicted to bash a Sandy-like creation with Henri. But it doesn’t look arsenic though the Fujiwhara effect volition beryllium almighty capable this clip to sling Henri arsenic acold westbound arsenic Sandy turned, nor is it apt to springiness Henri the spot of Sandy, which reached Category 3 astatine 1 point. (By the clip Sandy came ashore, it was backmost down to Category 1, which Henri is predicted to beryllium astatine landfall.)

Beyond that, Sandy was an highly ample storm. Its size and westward way conspired to thrust a catastrophic surge of seawater into New York Harbor. With Henri looking little utmost successful some respects, a large catastrophe for New York City and New Jersey is improbable this time.

There are reasons to anticipation that Henri won’t really beryllium disastrous anywhere. It is forecast to dilatory down and weaken earlier landfall. But it is excessively aboriginal to accidental that with confidence.

At this point, mentation and vigilance are precise overmuch successful order, particularly connected Long Island and crossed southeastern New England.