Forecast discussion: Despite high pressure off the east coast, mid-level clouds stayed over the area for most of Tuesday, and even produced some isolated showers. Now, the muggy weather will remain for the next couple of days, and we will feel the last few remnants of summer on Wednesday.
A strong warm front has passed through New England, allowing the dewpoint temperature to increase through the day. This will make the air very muggy tonight, and it will be tough to sleep this evening without air conditioning. There will be low clouds and patchy fog, and there may be some mist and drizzle falling in some spots. This fog will burn off by mid-morning, and temperatures will be increasing. In fact, parts of eastern Massachusetts has a Heat Advisory in effect from 1 p.m. to 6 p.m. on Wednesday. This is due to the heat index temperatures expected to be in the middle to upper 90’s. For those going to beaches Wednesday night, please be careful swimming. Some swells from Tropical Storm Gabrielle will arrive by early Thursday morning, causing some rip tides.
As we head into Wednesday night, a cold front over the Great Lakes will be moving towards the area. This front will help kick off some showers and thunderstorms before dawn Thursday morning. This will continue throughout the day and evening. Some thunderstorms could be severe, and some areas may see localized flooding due to heavy rainfall. The front will move offshore by Friday morning, allowing for high pressure to clear our skies. The high will also bring down much cooler air from Canada, and our daytime high temperatures will only reach the middle 60’s on Saturday. Temperatures will slowly return to normal for mid-September, with highs in the lower 70’s on Monday, and temperatures in the lower 50’s in the evening Sunday through Tuesday.
Meanwhile, the tropics have become quite active since last night. Along with Tropical Storm Humberto, Tropical Storm Gabrielle re-formed, after the National Weather Service stopped issuing advisories on the system back on Thursday evening.
As of 8:00 p.m. EDT, Gabrielle was centered at 31.9N 64.9W, or about 30 miles southwest of Bermuda. Maximum sustained winds were at 60 mph, and was moving to the north at 10 mph. The system will maintain its strength, before some slight weakening within the next 12 hours. Gabrielle will move more to the northwest over the next 48 hours, before she begins to move towards the cold front that will be well offshore on Friday afternoon. It poses no threat to the east coast at this time.
Tropical Storm Humberto is centered at 15.0N 28.1W as of 5:00 p.m. EDT, or 245 miles west of the southernmost Cape Verde Islands. Maximum sustained winds are at 70 mph around the center. It needs 74 mph winds to be called a hurricane. Humberto was moving northwest at 8 mph. The forecast for Humberto is to become a hurricane within the next 6-12 hours. The system will reach maximum winds of 90 mph within 36 hours before weakening. From there, the system will move into cooler waters and wind shear. The system will slowly turn to the north-northwest within the next 5 days. It poses no threat to any islands at this time.
72 hour forecast:
Tonight: Low clouds, patchy to dense fog, and muggy. Some drizzle is possible within fog. We will see a low of 71.
Wednesday: Fog and low clouds burns off by mid-morning, with partly sunny skies. It will be hot and humid, with a high of 91. Winds will come from the southwest at 10-14 mph.
Wednesday night: Overcast skies with possible showers or thunderstorms before dawn. We will see a low of 73. Winds will come from the southwest at 10-13 mph.
Thursday: Scattered showers and thunderstorms with a high of 85. Some rainfall could be heavy at times.
Thursday night: Showers, periods of rain, and isolated thunderstorms with a low of 69.
Friday: Showers/rain ending by the late morning. Mostly sunny skies expected by the late afternoon. We will see a high of 76.
Friday night: Clear skies and much cooler with a low of 54.
Saturday: Mostly sunny. Highs 64-67, lows 48-51.
Sunday: Mostly sunny. Highs 69-72, lows 51-54.
Monday: Partly sunny. Highs 71-74, lows 51-54.
Tuesday: Mostly sunny. Highs 67-70, lows 51-54.