Barometric Pressure Forecast for Greenwich, Connecticut
Barometric pressure forecast for Greenwich, Connecticut — Connecticut's southwestern corner on Long Island Sound, in the path of nor'easters that deepen off the Mid-Atlantic coast. See current barometric pressure and what it means for weather-sensitive people.
Download Pressure Pal to track barometric pressure and get migraine alerts for Greenwich and your area.
Pressure and weather in Greenwich
Greenwich occupies the westernmost point of the Connecticut shoreline, its coves and peninsulas facing south across Long Island Sound with the north shore of Long Island a dozen miles away. The Sound is a genuine climate feature rather than scenery: its water moderates overnight temperatures near the shore, and it removes the open-ocean fetch that would otherwise batter the coast. The defining influence on barometric pressure here is the nor'easter. Low-pressure systems form or reintensify near the Carolina coast, then track northeast along the temperature contrast at the Gulf Stream's northern edge, deepening rapidly as they go. By the time one reaches the latitude of Long Island the central pressure can be extraordinarily low, and Greenwich sits on its western flank where the gradient is tightest. Falls of thirty hectopascals over a day and a half are not unusual in a strong event. From late summer into October the other risk is a tropical system recurving up the eastern seaboard, which brings the deepest readings the town ever records. Between systems, and especially in high summer, the barometer can sit almost motionless under the Bermuda high for a week. Watch a barometric pressure forecast for Greenwich most closely from November through March, and again in September.
What this means for you
Can barometric pressure cause headaches? Coastal southwest Connecticut alternates between long flat spells under the Bermuda high and rapid, deep falls when a nor'easter bombs out offshore, and it is that contrast rather than the absolute reading that so many weather-sensitive people here respond to. Track current barometric pressure and its rate of change in Pressure Pal, use it as a headache tracking app, and you can usually see a weather migraine pattern forming a day before the storm arrives.