Oct 26, 2016 10:29 PM
NH1 First Alert Weather: Rain Arrives, Weekend Improvement
NH1 Chief Meteorologist
A frosty cold start to the day on Thursday with skies quickly clouding over with a thickening cloud deck. An area of low pressure will approach from the west High pressure will be supplying low level cold dry air with temperatures running below average for this time of year. Thursday morning will be dry which will allow temperatures to warm up some before precipitation moves in. Highs will climb into the mid 40's with a developing cool and raw onshore wind. As a warm front begins to shift north, rain will begin to overspread the region from west to east during the afternoon and evening hours on Thursday. The exception will be at elevations mainly above 2,000 feet where it should be cold enough for accumulating snow. The Monadnock region may see a brief burst of wet snow before a change to rain. This is where enough cooling owing to evaporation, melting, and ascent could allow for a period of snow at the start even in lower elevations, possibly allowing for a light coating on grassy surfaces late Thursday afternoon. Remarkably, Snow accumulations could reach 8 or 10 inches above 2,500 feet as it will snow most of Thursday night into Friday on the northern summits! This should turn out to be quite the winter event for our northern summits of the White Mountains!
Otherwise, as low pressure develops Thursday night in noreaster fashion, rain will become heavy at times at most locations. Heaviest rain will fall during the after midnight Thursday night, through the early morning Friday. The heaviest precipitation Friday is expected in the morning when the strongest ascent is occurring. The snow still likely falling at the highest elevations in the mountains. Many areas will be seeing close to an inch or more of rain which may lead to some localized poor drainage flooding in the worst downpours.
Easterly winds will also increase as Thursday night progresses with gusts between 30 and 35 mph possible on the coastal plain after midnight. Low pressure will slowly move eastward in the Gulf of Maine on Friday. Winds on the coastal plain may peak around 40 mph on Friday. This may cause some power outages. Rain will taper off and gradually end from SW to NE during late Friday morning and through the afternoon, except in the north and east where it may take til early evening.
Another quick moving system will move across the region Saturday, bringing clouds and a few rain showers to the region. High pressure moves in Sunday through Tuesday with fair skies a gradually moderating airmass heading into next week.