Forecast discussion: A weak area of high pressure gave Boston one last dry day of weather, as we had a mix of sunshine and at times overcast skies. We will have one day of decent weather, before Southern New England begins to feel the full effects of Hurricane Sandy.
Earlier this afternoon, Governor Deval Patrick issued a State of Emergency for Massachusetts. A Coastal Flood Watch is in effect from 6 AM Monday morning until 1 PM Tuesday afternoon. A High Wind Watch is in effect from early Monday morning into Monday evening. Also, a Storm Watch is in effect for Cape Cod Bay north to the Boston Harbor from Monday morning into Monday evening. But, a Hurricane Force Wind Watch is in effect for Buzzards Bay from Monday morning into late Monday night.
As of 8 PM EDT, Hurricane Sandy looked quite disorganized, based on latest satellite imagery. It is centered at 30.5N 74.7W, or about 355 miles east-southeast of Charlestown, South Carolina. Maximum sustained winds are at 75 mph, and is moving to the northeast at 13 mph. So far, Sandy has been following the computer models’ thinking, taking a turn to the northeast, before slowly turning back to the north on Sunday. But, the two biggest questions remain: when will it hook back to the west, and where will it make landfall?
According to the latest National Hurricane Center forecast, Sandy will make that turn back to the east coast early Monday morning, between about 2 to 4 AM. Between 4 to 6 AM on Tuesday, it will track to the west-northwest, and will begin to make landfall somewhere in southern New Jersey. This new placement is slightly north of last night’s forecast, where they moved the system into the Delaware Bay. However, the newest hurricane models suggest landfall could be slightly further north, near central New Jersey. The best placement would put it just south of Toms River, NJ. So, the forecast could change over the next 24 hours. However both the American and European models have been in great agreement over the last couple of model runs.
So, based on the current forecast, what does this mean for Boston? Well, we will begin to see tropical storm force winds by sunrise on Monday morning. Winds will slowly increase through the day, with maximum winds of 35-45 mph, with possible wind gusts of 65 mph. Also, we should see our maximum rainfall on Monday, although the computer models are only projecting about 1.25 inches in total. I feel that is very low, considering if we see any strong rain bands. So, I will lower my total rainfall for the system to about 2-4 inches.
Also, the strong winds will create heavy seas and surf outside of Buzzards Bay. Also, coastal areas will see storm surge of about 4-7 feet along the south coast, including the Cape and Islands. Waves outside of the Bay could reach 20-25 feet at its crest, before slowly receding into the end of the week. This may also create some coastal erosion, and water may move over any roads near the ocean, causing some street flooding.
Despite the lower predicted rainfall amounts, we could see numerous power outages from the winds alone through the state. So, please make sure you have flashlights, fresh batteries, and a working battery powered television or radio handy so you can keep up with news and weather updates.
The weather will begin to improve on Tuesday, as the low continues to work further inland and begins to weaken. Rain will taper off to scattered showers, and winds will begin to decrease, as the pressure gradient begins to relax. However, the remnants of Sandy will remain over the Northeast U.S. into Wednesday evening. A high pressure system will begin to push the former tropical system off into Nova Scotia by Thursday night, allowing us to see some sunshine on Friday.
72 hour forecast:
Tonight: Mostly cloudy with a low of 51.
Sunday: Cloudy with some isolated showers by the afternoon and a high of 60. Winds will come from the northeast at 13-18 mph.
Sunday night: Light to moderate showers and increasing winds with a low of 50. Winds will come from the northeast at 15-25 mph.
Monday: Light to moderate rain with tropical storm force winds and a high of 62. Winds will increase to easterly 35-45 mph with gusts near 65 mph at times.
Monday night: Heavy rain with tropical storm force winds and a low of 57. Winds will shift to the southeast at 30-40 mph with gusts of 55 mph at times.
Tuesday: Heavy rain tapering to showers with winds decreasing through the day with a high of 65.
Tuesday night: Some leftover showers but remaining breezy with a low of 52.
Halloween: Scattered showers. Highs 59-62, lows 44-47.
Thursday: Showers ending by the early morning, becoming partly sunny by the afternoon. Highs 54-57, lows 40-43.
Friday: Partly to mostly sunny. Highs 53-56, lows 40-43.
Saturday: Mostly sunny and cooler. Highs 52-55, lows 41-44.