DATE: March 5, 2018

TIME: 9:30 AM

SUBJECT:  Upcoming Coastal Storm Wednesday/Thursday

Situation:

The National Weather Service is forecasting another coastal storm to bring snow and gusty winds to New England starting Wednesday morning and continuing into Thursday.

Rain/Snow:

• Snow is forecast to begin mainly after the Wednesday morning commute and continue through Wednesday night before tapering off during the morning commute on Thursday. The greatest impact appears to be the late day Wednesday commute and possibly lingering into the Thursday morning commute.
• Snow may fall at a rate of as much as 1-2 inches per hour at the peak of the storm late Wednesday into Wednesday night.
• A potential change to rain is possible for portions of eastern Massachusetts, but the location of the rain/snow line remains highly uncertain. The changeover from snow to rain would most likely take place late Wednesday afternoon or evening. In the vicinity of the rain/snow line, snow is likely to be wet and heavy.
• Snowfall totals could reach 8-12 inches over much of Massachusetts, with 6-8 inches falling in parts of far western Massachusetts and the Connecticut River valley, 4-6 inches in the vicinity of the rain/snow line, and up to 2-3 inches in southeastern Massachusetts.

Winds:

• 30-40 MPH wind gusts, with up to 50 MPH gusts over the Cape and Islands, are forecast, with the strongest winds occurring Wednesday night into Thursday morning.

Coastal Flooding:

• A storm surge of around 2.5 to 3 feet and 15-20 foot waves just offshore are forecast.  At worst, this could result in minor coastal flooding and moderate beach erosion for the early Thursday morning high tide (generally 3:30 AM to 4:30 AM along the MA east coast). This will likely be the only high tide with any coastal impacts.

Uncertainty:

• This storm has yet to form and is still more than 2 days away. Small scale details such as the exact location of the rain/snow line are not usually known with high forecast confidence until 24-36 hours prior to the event.
• A slight shift in storm track will determine whether the heaviest snow would occur across Connecticut into western-central Massachusetts, or farther east into Rhode Island and eastern Massachusetts, impacting the Boston to Providence corridor.
• The location of the rain/snow line remains highly uncertain, ranging from as far west as the Connecticut River Valley to as far east as the Cape Cod Canal.

Impacts:

• Storm surge and offshore wave action could result in minor coastal flooding and moderate beach erosion during the early Thursday morning high tide.
• Heavy snow and gusty winds will result in hazardous travel conditions due to slippery road conditions and lowered visibility from blowing and drifting snow. Both the Wednesday evening and Thursday morning commutes may be impacted by this event.
• Heavy wet snow in the vicinity of the rain/snow line may result in downed tree branches/limbs, increasing the risk for isolated power outages.
• Gusty winds may cause scattered tree damage, isolated power outages, and possible structure damage, especially in eastern Massachusetts.