Posted at 11 PM Sunday, September 4, 2016
Good evening! I will be discussing the (relatively few) local impacts that post-tropical Hermine will put on our region. First off, a quick warning: guidance is still mixed, and thus this entire week has low confidence so stay tuned for later updates.
Location and Forecast Track
As of 11 PM, Hermine was off the mid-Atlantic coast. Hermine is forecast to make a slight shift to the northwest before turning northeast; the highest chance for impacts will be tomorrow into Tuesday. Here is the latest map from the NHC, freshly issued:
There will be a chance of showers on Monday and Tuesday, and mainly in Eastern MA and RI: perhaps beyond southeast New Hampshire and southwest Maine, the shower risk is near or at zero in much of Northern New England. Meanwhile at least some showers are likely for most of eastern Massachusetts and Rhode Island, with rain expected at times on the south coast, Cape, Islands, etc. Central and Northeast MA and Eastern CT will have a chance of showers but lesser than Boston and points south. Meanwhile, showers are unlikely further to the west and north.
There is a roughly equal chance of showers between Monday and Tuesday while the risk is decidedly less for Wednesday across the board in SNE, meanwhile there is a low shower risk in coastal Maine at this point.
Flooding is not expected.
A Tropical Storm Warning is in effect for coastal CT east of New Haven, coastal RI, and south coastal MA, also including Cape Cod, Martha’s Vineyard, Nantucket, and Block Island; where winds to 40 mph with gusts 40-50 mph are likely. Elsewhere in eastern MA, and perhaps into far southern NH, winds will be gusty at times but below tropical storm levels, although gusts nearing tropical storm equivalence are possible just north of the warning area. The further north and west, the lighter the winds: by the time you get into northern MA, you are in run-of-the-mill gusty wind territory.
Coastal Flooding, Storm Surge, and Beach Erosion
Some beach erosion is possible on the south coast, but nothing major is expected.
Storm surge will be 1 to 2 feet on the south coast of MA and Cape Cod with 2 to 3 feet likely on the islands and south coastal RI. No surge is expected in NH/ME or east coastal MA.
Lower tides have reduced the risk for coastal flooding but scattered instances of tidal based coastal flooding is possible on the south coast.
A High Surf Advisory is in effect for the entire coast of New Hampshire and Maine for 5 to 9 foot waves. For the Downeast Maine coast (NWS Caribou area) the advisory is from 8 AM to 11 PM tomorrow; in the NWS Gray area (all of NH coast, and Maine coast from Rockport to the NH line) it is from 2 AM tonight (tomorrow) to 8 AM Tuesday.
A high rip current risk exists for all of the New England coast (the east coast of MA is technically under a moderate rip current risk for Monday but it is still going to be hazardous).
Overview for Land
Most wind and rain impacts confined to southeast MA and coastal RI, and they won’t be anything major. Gusty winds, scattered showers in eastern/central MA, perhaps southeast NH and far southwest ME.
Have a good night!