Weather: The Cold, Hard FactsBy Greg Lawson and Pablo Zurita
For this end of term forecast, we have decided to view the present synoptic situation in a more theoretical context. A strong upper-level trough is beginning to exhibit an LC 2 (cyclonic shear) signature. This suggests there will not be much equatorial propagation of wave activity, i.e. very little dissipation through Rossby wave-breaking at the critical level of the sub-tropical wave guide (analogous to a less-absorptive cavity in refraction theory). This means longer lasting structural coherence of the upper-level disturbance and hence greater probability for surface cyclone deepening due to the advection of the lower-level isentropes in the baroclinic zone by the winds induced by the upper-level anomaly. Though the cyclone will deepen well off the coast due east of the Delmarva Peninsula, it will retrogress northwestward due to the cyclonic wrap-around of vorticity and threaten Southern New England with precipitation. Despite the low values of convective available potential energy over Boston and the South Shore, convection may still be induced by the large-scale moisture fluxes meaning rain and possibly snow showers. However, as we expect the storm’s reach to stay south of the Boston area, we shall leave the probabilistic precipitation forecast for Cambridge below 35 percent -- expect no more effects than simply strong winds.
Today: Chilly. Variable cloudiness. Northerly winds with speeds
increasing through the day. High of only 37°F (3°C).
Tonight: Cold, windy, and mostly cloudy. Low of 25°F (-4°C).
Wednesday: Cold and windy. Slight chance of snow showers. High of
freezing with wind chills possibly reaching 0°F (-18°C). Low of 20°F (-7°C).
Thursday: Variable cloudiness and a slow warming into the 40s (5°C).