The little system that I was advertising got ripped apart as it traveled eastward last night so there were only scattered snow showers with some locations seeing dustings. An area of high pressure today will set the stage for our much larger storm for Saturday night through Sunday. This storm still has alot of questions, here is what we do know.
Map (Far left) 1. Winter weather warning in the pink from Saturday evening through Sunday evening. This is for snow for NH, VT and Maine. Snow, sleet, and freezing rain MA, RI and CT.
Winter weather advisory in purple for snow, sleet and rain for same time frame. Saturday evening through Sunday evening.
- Its going to be a high impact storm, with Heavy snow, sleet, freezing rain and some wind.
- This is not a block buster wind and snow event but there will be enough wind that could cause minor to moderate coastal flooding concerns.
- The wind that does happen will have a higher impact due to the amount of snow and ice anticipated.
- There will be a snow/sleet line and a rain line as a coastal front forms as well as warm air intrusion aloft.
- Precipitation should start as all snow for the region, with the exception possibly the outer cape and Nantucket.
Unknowns
- How much moisture is actually going to be with this system. This would greatly determine snow and ice amounts.
- When does the change over start to happen and move north. The later this happens the more snow
- How much of the layers of the atmosphere below freezing, Is there more sleet or freezing rain? How large an area does it sleet vs freezing rain?
- When does the precipitation end, Mid Afternoon or early evening. It looks to be a 20 to 24 hour event
- When does the change over back to snow happen in the afternoon. The sooner it is, the more snow and less ice
Map 2.
Current thoughts on Precipitation. Snow should over spread the region from west to east between 5pm and 9pm quickly becoming heavy. Precipitation should start to change and flip to sleet and rain on the cape and Islands.
Snow should change to a period of sleet and freezing rain and could change to rain across portions of southeast Massachusetts.
Snow should change to a period of sleet and freezing rain along and south of the pike Sunday morning from south to north, east to west. This is an area that could see high ice accumulation. It should end as a period of snow before the precipitation ends.
North of the pike and south of RT2 up into northeast massachusetts, it should remain snow but there will likely be a mix of snow and sleet across Northeast Massachusetts where there is also a chance of freezing rain before it changes back to all snow sometime in the afternoon.
It should remain all snow north of RT 2, Northwest Mass, up into VT, NH and Maine. There is a chance that sleet mixes in around RT2 and up along I95 in NH.
Snowfall. Map 3.
0-2 inches with localized 3 inches possible on the Cape and islands
2 to 6 inches from southeast CT, southern RI into southeast Massachusetts.
6-12 inches most of CT, up into Central and eastern Massachusetts.
A general 10 to 20 inches for western and north central mass up into Vermont, New Hampshire and Maine. Local areas reaching up to 2 feet are possible.
In terms of the snowfall amounts, if there is more mixing with sleet and freezing rain then lower snow fall amounts ( lower parts of the ranges) If there is less than there is more ( higher end of the snowfall)
The further north and west you are the higher the snowfall.
Ice accumulation. Map 4.
Another major aspect of this storm could be the ice potential. Not everyone in the red shaded areas will receive 0.2 to 0.3 inches of ice accretion. Some where in the red shaded area looks to receive this. It is just hard to pin point where this will happen but the best bet is some where within this red shaded area. At this time I feel Southern Ct, northern RI up into the Taunton/Foxborough area has the best chance of seeing ice accretion in the 0.2 to 0.3 inch range. The areas around and south of Mass Pike look to get at least 0.10 inches of Ice. Areas north of the mass pike when or if warm air aloft makes it pass, could very well be all sleet but there is a chance for freezing rain up through Northeast Mass it would be greatly dependent on how far the warm air makes it.
Map 5. Road conditions. Very bad road conditions are anticipated. with Level 4 and 5 road conditions throughout most of Southern New England. The worst of the driving is in red. These areas have a chance of lots of snow but also lots of ice which is a very bad combination.
Power outages are likely especially along and south of the pike.
Winds look to be 10 to 15 MPH with gusts up to the 30s inland with winds 15 to 25 with gusts up in the 40s along the coast.
As the storm pulls away there will be a flash freeze and any liquid and any wet snow will become as hard as a rock and remain that way for a few days. The wind will also stay with us Sunday night and Monday. With lows going around 0 Sunday night with wind chills below that. Monday as the storm departs, very cold air will settle in with highs stuck in the single digits up to around 10. Wind chills will remain under 0 for the day. Tuesday will warm up a bit and will get temperatures up into the 20s. A front looks to move through middle of the week sending rain, sleet and snow showers to the region. A larger system could impact the region later this week. Details on this system will have to wait.
Forecast for the Merrimack Valley.
Rest of Today. Partly cloudy, highs in the mid to upper 30s.
Tonight. Partly cloudy lows in the low to mid 10s.
Saturday. Increasing clouds. Highs in the low to mid 20s.
Saturday night. Heavy snow developing. Becoming breezy. Lows in the mid to upper 10s. Wind chills around 0 and single digits. Areas of blowing snow.
Sunday. Heavy snow. Heavy snow, sleet and freezing rain south. Breezy, Highs in the 20s. Temperatures dropping in the afternoon. Precipitation ending late. Areas of blowing snow. total snowfall accumulation of 10 to 20 inches. Highest amounts North.
Sunday night. Clearing skies, Cold. Lows around zero. Breezy, Wind chills around 10 to 15 below.
Monday. Sunny, Breezy, highs in the single digits. Wind chills 10 to 15 below possible.
Monday night. Mainly clear, Lows in the single digits to around 0.
Tuesday. Warmer, Mostly to partly sunny, highs in the low to mid 20s.
Tuesday night. Becoming cloudy lows in the 10s.
Wednesday. Mostly cloudy, Chance of rain, sleet and snow show showers.Highs in the 30s.
Wednesday night. Cloudy chance of snow showers, lows in the 20s.
Thursday. Mostly cloudy. highs in the 30s.
NOTE. todays afternoon weather models have gotten warmer again sending the mix line further north. The models look to continue going back and forth. Update tonight. The warmer solution more sleet/freezing rain across the interior, the Colder solution more snow. I am going middle of the road.
Merrimack Valley Weather 