Arctic Front to Bring Squalls, Cold Temperatures to New England Thursday

Yesterday's storm continues to steadily march away from New England this morning. A wide swath of 6-12 inches of snow fell across interior New England, with a steep cutoff moving toward the southern New England coast. As of writing (more snow reports are likely to come in through the day today), Freedom, New Hampshire hit the jackpot with 12.6 inches reported.

Below: Snowfall reports as of 7:45am Wednesday:

After a calm day under high pressure for Wednesday, an Arctic cold front will drop through New England during the day Thursday. The front will likely enter northernmost New England pretty early in the morning (around sunrise) and steadily push through the region through the day. The front will likely have cleared southernmost New England by the evening. This front will be bringing a blast of very cold air along with the potential for scattered snow squalls.

On the snow squall front, there are several ingredients that will line up to bring northern New England potentially widespread squall activity. First, the daytime passage of the front means instability will be plentiful for squalls. A small amount of CAPE will be present (which is an indicator of instability, often talked about in regards to summertime thunderstorms). Sufficient moisture and steep lapse rates (the rate of temperature decline with altitude; a steep lapse rate indicates a rapid decline and is a sign of instability) will also be present.

All of this points to potentially widespread and impactful snow squalls across interior northern New England. Moving toward the coast of northern New England and into southern New England, the same ingredients will be in place, but likely more muted. Instability and steep lapse rates will certainly be present, but moisture will be much less. Southern New England will likely be contending with dry mid-levels, which will likely cause the snow squalls to weaken and break up as they move southward.

Below: RGEM showing potential weather around mid-afternoon Thursday:

Any snow squall anywhere in New England tomorrow will have the chance to bring a brief hit of heavy snowfall (around 10-30 minutes). Snow squalls have the chance to drop a quick inch or two of snow before rapidly moving away. These will also have the chance to bring wind gusts of 30-35mph, leading to white-out conditions for a brief time. Squalls will be likely in the morning hours for interior northern New England and the afternoon and evening for southern and central New England.

Winds will likely continue to whip after the frontal passage. Gusts of 30-40mph will continue through the day, evening and into the overnight hours. Once the winds pick up, you'll know the Arctic air has arrived. Temperatures will drop off behind this front, with the northern tier of New England likely seeing falling temperatures through the day. Southern and central New England will see a passage late enough in the day for at least some daytime heating to occur before the temperatures drop off later in the afternoon.

Below: HRRR showing hourly temperatures from 7am through 7pm Thursday:

Temperatures will continue to free fall through Thursday night for many, with lows bottoming out Friday morning in the negative single digits for a majority of New England (northernmost New England will likely see temperatures stall around 0° after dropping to it early in the night). With wind gusts remaining in place, wind chills will be in the -10s and -20s across the north with negative single digits across southern and central New England. Friday afternoon will see some improvement, but it will remain cold, with teens and 20s for highs region-wide. Winds will be lighter, but still enough for a wind chill factor.

Toward the end of the week, flow will likely transition to more zonal, which may lead to an active, but low-impact pattern. A couple waves will move through this flow, the first coming later Friday into Saturday. This will likely feature northern stream energy moving across Canada with southern stream energy staying well south of New England. With zonal flow in place, the southern streamer looks to push well offshore of New England, with lighter showers possibly making it to southernmost New England.

The northern streamer may be able to produce some snow showers across interior New England, but accumulations look minimal at this time. Trends will be watched for the rest of this week in regards to exact track and timing, as this will determine just how much snow/rain showers are able to develop Saturday.