Forecast discussion: A weak frontal boundary over eastern Massachusetts brought some heavy rainfall and scattered thunderstorms earlier this afternoon for the central and eastern part of the state. At this time, a weak warm front will slowly work its way from the west into Southern New England on Wednesday, bringing a greater chance at more widespread precipitation for Boston.
At this time, the frontal boundary is just a weak disturbance. Temperatures will be slightly warmer than today, as highs reach the lower 80’s. However, we will see more widespread shower and thunderstorm activity, especially during the mid-morning and afternoon hours. As we head into the evening, a cold front moving through the eastern Rockies will make its way into the Great Lakes. This front will begin to push into the Mid-Atlantic on Thursday afternoon, helping to trigger more showers and thunderstorms.
The front will slowly push offshore by Friday morning. At this time, the American model has been very inconsistent with its forecast. It has been flip-flopping on whether the front moves completely offshore, or develops a weak low to our south, which keeps precipitation in the area until late Friday night. The European model dries us out, but the United Kingdom model keeps a weak low off the coast of Long Island. Finally, the Canadian model just moves the front offshore by Friday morning. After examining all the models, the European has stayed mostly consistent the last few days, so I will keep partly sunny skies in the forecast for the afternoon.
Once the front moves offshore, high pressure will control our weather pattern right into early next week. However, once the winds shift back to the southwest, temperatures and humidity will increase once again. We may return to 90 degree heat by next Monday, especially away from the coastline.
Meanwhile, Tropical Storm Chantal is centered at 15.4N 64.9W, or about 220 miles south-southeast of San Juan, Puerto Rico. Chantal has maximum sustained winds of 65 mph, with gusts as high as 80 mph, and is moving to the west-northwest at 26 mph. Most of the Caribbean islands are under a Tropical Storm Watch or Warning, with a Hurricane Watch in effects for parts of the Dominican Republic. The track has changed slightly since last night, with Chantal moving over the southwestern side of the Dominican Republic Wednesday afternoon, before moving into Haiti. It now appears Chantal will move along the western side of the Bahamas late Thursday afternoon, and remaining a Tropical Storm. The long range forecast has Chantal about 250 miles away from the South-Carolina Georgia border Sunday afternoon. At this time, it is not sure if we will see the remnants of Chantal late next week. Furthermore, it is possible the Bermuda High brings Chantal inland, or dissipates off the Atlantic coastline as a Tropical Depression.
72 hour forecast:
Tonight: Mostly cloudy with patchy fog developing, especially along the coast. We will see a low of 67.
Wednesday: Overcast with scattered showers/thunderstorms throughout the morning and afternoon. We will see a high of 83 with south winds at 11-14 mph.
Wednesday night: Cloudy with scattered showers/thunderstorms and low of 72. Winds will come from the south-southwest at 8-11 mph.
Thursday: Cloudy with light to moderate rain and isolated thunderstorms. We will see a high of 84.
Thursday night: Scattered showers, periods of rain, and isolated thunderstorms with a low of 67.
Friday: Showers end by the morning, and becoming partly sunny by the late afternoon. We will see a high of 77.
Friday night: Mostly cloudy with a low of 65.
Saturday: Partly sunny. Highs 81-84, lows 64-67.
Sunday: Mostly sunny. Highs 84-87, lows 67-70.
Monday: Mostly sunny. Highs 86-89, lows 68-71.
Tuesday: Mostly sunny. Highs 87-90, lows 70-73.