8:23AM
DAYS 1-5 (DECEMBER 31-JANUARY 4)
The final day of 2018 has arrived. The the final sunshine of the year will be this morning and maybe first thing this afternoon for parts of the region before cloudiness thickens up ahead of a quick-moving storm system that is going to symbolize much of 2018 – wet weather. Actually this system has just enough cold air to work with that it may start as snow or a mix over interior southern NH and central to northeastern MA, and for a short time where snow occurs it may even look like it would be the start of a serious snowfall, but it will be very fleeting, as warmer air takes over both at the surface and aloft and everyone is rain by the time we flip the calendar from 2018 to 2019. So if you are going to be outside somewhere to celebrate, bring the rain gear. If you are near the coast, say, in Boston, leave the umbrellas at home and wear a rain coat as the wind will be on the gusty side this evening and tonight. When we get to the first dawn of 2019, clouds and a few rain showers may still be around as we’re immersed in mild air, but a quick drying process on an increasing westerly wind behind the system will make for quite a nice New Year’s Day overall, although the mild air that starts the day will be replace as the hours go by with much colder air, so be ready for a temperature drop. High pressure will build in with dry and cold air Wednesday. A northern stream disturbance will pass through the region Thursday morning and midday and may cause a little very light snow. Later Thursday and early Friday a piece of energy will travel well south of the region, but a lagging piece of energy from the southern jet stream will phase up with a piece of energy from the northern jet stream over the Midwest and create a storm system that arrives along with milder air, bringing a good chance of rain to the region by later on Friday. It’s possible this system is slow enough so that the entirety of Friday’s daylight is dry. Will tweak timing going forward.
Forecast details…
TODAY: Increasing cloudiness. Highs 37-44. Wind S to SE up to 10 MPH.
TONIGHT (NEW YEAR’S EVE): Overcast. Rain arrives evening southwest to northeast, may start as mix/snow interior southern NH and northeastern to central MA. Rain diminishes to scattered rain showers west to east overnight. Patchy fog. Temperatures rise slowly through the 40s. Wind SE to S 5-15 MPH inland and 15-25 MPH coast evening, S to SW 10-20 MPH with higher gusts all areas overnight.
TUESDAY (NEW YEAR’S DAY): Mostly cloudy with a lingering rain shower possible very early, then a sun/cloud mix. Highs 48-55 in the morning. Temperature fall through the 40s afternoon to the upper 30s east and middle 30s west by day’s end. Wind W increasing to 15-30 MPH with gusts 40-55 MPH, strongest in higher elevations.
TUESDAY NIGHT: Partly cloudy early then clearing. Lows 18-25. Wind W 15-30 MPH with higher gusts evening, diminishing overnight
WEDNESDAY: Mostly sunny. Highs 28-35. Wind NW 5-15 MPH.
THURSDAY: Mostly cloudy with a risk of very light snow morning and midday then clearing during the afternoon. Lows from the upper 10s to lower 20s. Highs in the 30s.
FRIDAY: Clouding over. Rain arrives at night. Lows in the 20s. Highs in the 40s.
DAYS 6-10 (JANUARY 5-9)
Rain may end as snow or snow showers during January 5. A few snow showers possible January 6. Risk of light snow or flurries later January 7 and January 8 then fair and cold January 9 as the southern jet stream retreats and the polar jet, sitting mainly north of the region, sends minor systems this way.
DAYS 11-15 (JANUARY 10-14)
Unsettled weather is most likely during the second half of the period though at this point no major storms appear likely.