July 15, 2017
TLDR: Go here to check the current auroral oval: NOAA Space Weather Prediction Center - Aurora - 30 Minute Forecast look near the bottom right of the image and see if the white, yellow, or orange part of the ring is over Massachusetts or New Hampshire.
UPDATE: (1:50 EDT Sep 12, 2014): The shockwave has hit from the second flare. Aurora may continue to develop, but I'd check both right after twilight, and again in the 11pm to 1am time frame.
UPDATE: (8:11 EDT Sep 12, 2014): We've had another big one. A Major X-class flare erupted on the Sun on Tues. Sept. 9, 2014, followed by another, larger one on Wednesday which means that we have an Aurora forecasted for September 12
For the greater Boston area, it will still be low towards the horizion. Look for a greenish glow to the North with best viewing under dark clear skies near midnight. This animated model shows the predicted progression of the plasma pulse, from the solar flare as it reaches the Earth on the right and the two STEREO spacecraft on the left: WSA-ENLIL Solar Wind Prediction
UPDATE: (8:18 EST Jan 10, 2014): Alas, the coronal mass ejection (CME) from the solar flare arrived at Earth yesterday afternoon our time, so the only folks who got a nice show out of it were in Scandinavia & Northern Scotland. So if you went outside and didn't see anything (except the Moon, stars, and possibly Jupiter) then it wasn't because you weren't looking in the right spot.
UPDATE: (3:47 EST Jan 9, 2014): The ACE Satellite started seeing a magnetic field sharp rise in intensity around 2:30 EST, and has persisted since as of this writing. The shock may have already arrived by now, but Aurora aren't visible in the day time. I'd start looking north and low to the horizon as soon as it gets dark. The POES maps hadn't updated more recently than from around 2pm as of this writing.
UPDATE: (11:30 EST Jan 9, 2014): University of Alaska's Geophysical Institute has an Aurora Forecast updated daily. For Jan 9th, they're predicting an aurora visible low on the northern horizon, as far south as Boston.
(8:30 EST Jan 9, 2014): On Tuesday, January 7, 2014, a huge solar flare erupted, sending vast amounts of plasma hurtling out along its magnetic field lines and towards the Earth. When that plasma hits the Earth's magnetic field, we should get a more intense aurora than usual, which may well make it visible in Massachusetts.
Space.com's article about the flare from January 7, 2014 includes a video showing the event in many (non-visible) portions of the spectrum.
(Here is another 15 second closeup in the near infrared portion of the spectrum: SDO Captures Release of X1.2 Class Solar Flare.)
For scale, note that the Sun is about 100 Earth's in diameter.
Will we actually be able to see the aurora here? It depends on whether we have a clear sky (current forecasts @7pm July 15 2017 show clear skies from 9pm Sunday until 2am) and on the shape of the northern "auroral oval".
Plasma is a neutral mixture of positively charged ions and negatively charged electrons. It is both steered by and reshapes magnetic fields. So when a huge blast of it comes towards the Earth, it beats on our own magnetic field like a drumhead, distorting its shape. This can bend the field in a way to make it more intense at more southerly latitudes instead of its more usual state near the Arctic Circle. The collisions of the particles from the Sun with atoms in our upper atmosphere ionizes the atmospheric particles, causing the aurora itself.
We can see what the shape of the current auroral oval is by looking at data from the NOAA POES satellite here: POES Auroral activity map - North Look near the bottom right of the image and see if the white, yellow, orange, or red part of the ring is over Massachusetts or New Hampshire.
The time data on the map is given in UT (Universal Time). To convert to EST, subtract 5 hours.
If the warmer colored parts of the oval are nearby, look to the north for a glowing, cloud like structure, that may appear dimly green or red. Back in 1999 I saw one at UNH around 3am and that one filled the entire northern half of the sky.
More may be added to this page as I have time or find good links. See also:Space Weather.com