Well winter is certainly making up for lost time. After 2-4″+ fell for areas north of the Mass Pike on Tuesday, a blizzard swept through the region on Thursday dropping 10-16″ for most everyone. Thursday’s storm was particularly impressive for its high snowfall rates and for its abundance of lightning. A sign that the storm was very powerful.
Last night a weak storm system dropping through the Great Lakes brought a general 1-4″ for the area. Now that we have cleaned that off our cars and driveways, all attention turns to our next system…..tomorrow. But first we have to worry about a little freezing drizzle this afternoon, tonight and tomorrow morning across the Boston area.
Saturday afternoon and Sunday morning two weak area of low pressure will traverse the continent from west to east. One along the U.S./Canada border and another through the Ohio River Valley.
1 pm Saturday Afternoon Surface Map
By Sunday mid-morning as these two systems approach the Northeast, snow will breakout across Southern New England (SNE) from west to east (9 am Hartford, 11 am Worcester, 12 pm Boston). As this is occurring a new area of low pressure will develop over the Delmarva and become the dominant storm system.
1 pm Sunday Afternoon Surface Map
This new area of low pressure will explosively develop while drifting northeast. Passing very near the Island of Nantucket around midnight Monday morning the storm is forecasted to undergo bombogenesis. That is the central pressure of the storm is forecasted to decrease by 24 mb or greater in 24 hours or less. In this case it appears that the storm could strengthen from ~1004 mb to ~970 mb in about 18 hours.
Taking a closer look at the timeline for New England, snow overspreads SNE by 1 pm Sunday afternoon. Everyone outside of the Cape, Islands and extreme southeast MA starts as snow. Inside of 495 expect a heavier and wetter snow as temperatures are very near freezing.
1 pm Sunday Surface Map
Slowly but surely warmer air should work its way in over Plymouth and Bristol counties and along the southern shorelines of Rhode Island/Connecticut and we’ll watch as the snow flips over to rain. Just how far northwest the rain/snow line makes it inland will be key to the forecast.
7 pm Sunday Surface Map
By 1 am Monday morning the storm center is passing near Nantucket and really starting to strengthen. Around this time the rain/snow line will likely have made its furthest push northwest and in the coming hours will begin to slide back southeast as cold air wraps in from the north. Very early Monday morning there’s a hint of a trough like feature (blue dashes) connecting the strengthening storm with the rapidly dying one. There’s a chance that this could lead to a period of enhanced precipitation; especially along the New Hampshire seacoast.
1 am Monday Morning Surface Map
By 7 am Sunday morning the storm is reaching it’s peak intensity (~970 mb) as it continues to drift northeast away from the Cape. All areas have transitioned back to snow at this time. Across Connecticut and western Mass the snow is beginning to taper off. The snow will continue to end from west to east during the morning hours.
7 am Monday Morning Surface Map
There is a chance on Monday morning that eastern SNE and the Cape could get into a few hours of very heavy snowfall. As the storm wraps up a very intense band of precipitation should form on the western side. If that band forms over eastern areas then it could make for a wild few hours. The image below shows the band just offshore, but close enough that it needs to be monitored. Right now my snow map accounts for the band impacting the outer Cape significantly and eastern areas slightly.
By 1 pm Monday afternoon the storm is really starting to pull away now. The last of the snow will taper off shortly after this time. Meanwhile, eastern Maine is still in the thick of it.
1 pm Monday Surface Map
Also impressive during the day on Monday will be the winds associated with the system. Wind gust across the region on the order of 30-40 mph are expected. Higher gusts along the shoreline, southeast MA, Cape & Islands are expected.
1 pm Monday Wind Gusts (knots)
When all is said and done a general 1.0″-1.5″ of liquid precipitation will fall over the region. Except for along the Maine coast where greater than 2″ of precipitation is possible. Unfortunately not all of it falls as snow for southern portions of the area. Snow totals increase from south to north as a result.
Total Precipitation
As for snowfall amounts, here is where it gets tricky; especially across those regions that mix or turn to rain. As of right now, here is what I am thinking.
-Chris
Chris Hampton Weather 