10:43AM<\/p>\n
A rather benign weather day today, probably welcomed by everybody, as temperatures go above freezing allowing more of the melt\/refreeze ice to melt away and dry up. It’s not the brightest day as of the writing of this blog, as cloudiness formed by advancing warmer air aloft are blotting out the sun in much of southeastern New England, and will continue to do so through the middle of the day, before decreasing. Had we had the benefit of full sun today, the temperature may have gone into the 45-50 range, but the lack of sun and the still-short sunlight day means that a 40-45 range will be more accurate for most of the region (thought it is already 45 on Martha’s Vineyard as of 10AM).<\/p>\n
Turning attention to Sunday’s storm, which will be a rainstorm for the WHW forecast area of southern NH, eastern MA, and RI, it will be the result of a low pressure area moving rapidly north northeastward from the Gulf of Mexico today to crossing southeastern MA by Sunday evening. In an already mild air mass, and with more mild air coming up with the storm, the only place that will be cold enough for snow during the heart of the storm will be the mountains of western and northern New England. As the low passes the region and starts to wrap some colder air in, a mix\/change line will try to charge southeastward, but will probably be beaten by the end of the precipitation, which should clear the region by midnight, if not before. If it does snow in some of the higher elevations of southwestern NH and north central MA, accumulations would be minor. Other aspects of the storm: Rainfall totals of 1 to 1.5 inch, which will fall over a relatively short period of time, resulting in flooding of poor drainage areas; Wind gusts of 40-50 MPH on Cape Cod and the Islands from the SE in advance of the low center, with some minor damage and a few power outages possible.<\/p>\n
Beyond the storm: Monday will be a transition day with mixed sun and clouds. Two fronts or boundaries will come through, one around midday to early afternoon, the other in the early evening, from northwest to southeast. This will send us down a proverbial flight of stairs into the deep freeze, which will settle in at night. At this time it looks like both boundaries will come through devoid of snow shower activity, but never completely count out a flurry or squall with the passage of such boundaries.<\/p>\n
Arctic cold takes hold: Tuesday, the final day of 2013, and Wednesday-Friday, the first few days of 2014, will likely be dominated by Arctic air. That is the more certain part of the forecast. The less certain part is whether or not any snow will occur at some point during that time. To make a long story short, computer guidance will have trouble “figuring out” what to do with the boundary of the cold air and milder air to the south, and its interaction with pieces of energy moving along it, born of the remains of Pacific weather systems. Scenarios can range from dry weather to one or two near-misses, to a brushing or two with minor snow systems, to a major winter storm. It is just too early to be sure.<\/p>\n
For you more model-savvy folks, it’s a well known fact that operational runs of computer guidance will often miss the details so far in advance, while ensemble runs of the same models will pick up on storm threats. Such is the case this time, where the ensembles have been hinting more loudly of a storm threat somewhere along the East Coast in the January 1-4 period, where some of the operational runs have shown nothing, or hinted at something only to take it away on successive runs. These operational models are now starting to hint more at “something happening”. And more detail will come as we get closer to the event. Even with this much known, there is nowhere near enough confidence to forecast a storm of any kind for this area. It’s better to just keep that part of things on the back burner for another day or so, until the energy responsible for the threat is in a place where models start to handle it a little more accurately. So instead of trying to make it seem like I have a confident clue of the outcome up here in southeastern New England, you’ll find a low confidence generic-worded forecast for January 1-3 at the end of this update…<\/p>\n
Southeastern New England Forecast…<\/p>\n
TODAY: Lots of clouds through early afternoon, increasing sun west to east thereafter. Highs 39-46. Wind SW 10-20 MPH.<\/p>\n
TONIGHT: Mostly clear in the evening followed by increasing cloudiness later at night. Lows 25-32. Wind SW 5-15 MPH, diminishing.<\/p>\n
SUNDAY: Thickening overcast morning. Rain develops rapidly from south to north during the first half of the afternoon and grows heavier during the second half of the afternoon. Heaviest rain early evening, including the chance of thunderstorms Cape Cod & Islands. Rain ending south to north by midnight, but may end as mix\/snow in higher elevations of southwestern NH and north central MA where some minor accumulations are possible. Highs in the 40s, may break 50 Cape Cod & Islands, then falling back to the 30s at night. Wind E to SE 10-20 MPH, increasing to 20-30 MPH coastal areas and Cape Cod\/Islands, shifting more to the S and SW there toward evening and variable over southeastern MA (where the low tracks), then backing to NE and eventually NW over most of the region, NW to W over the South Coast region. Top wind gusts may reach 30 MPH anywhere near the coast and in higher elevations, and 40-50 MPH Cape Cod & Islands, lighter elsewhere.<\/p>\n
MONDAY: Variably cloudy. Lows in the 20s. Highs around 30 midday but dropping after.<\/p>\n
TUESDAY: Partly cloudy. Highs in the 20s but falling through the 10s for New Year’s Eve. Gusty winds develop and create very cold wind chill values.<\/p>\n
WEDNESDAY-FRIDAY: Periods of cloudiness and some threat of snow, timing uncertain. Very cold with lows commonly 0-10, highs 10-20, possibly a little higher South Coast.<\/p>\n","protected":false},"excerpt":{"rendered":"
10:43AM A rather benign weather day today, probably welcomed by everybody, as temperatures go above freezing allowing more of the melt\/refreeze ice to melt away and dry up. It’s not the brightest day as of the writing of this blog, as cloudiness formed by advancing warmer air aloft are blotting out the sun in much … Continue reading Sunday Storm, Arctic Air Arrives After<\/span>