Sep 13, 2016 11:29 PM
NH1 First Alert Weather: Wednesday T'Storm, Blast of Autumnal Air
NH1 Chief Meteorologist
National Weather Service Text Product Display A fast moving Canadian short wave with a strong associated cold front will move through the region in this afternoon. The day will be starting of with sunshine, but clouds will be increasing during the afternoon. Showers and thunderstorms in advance will accompany this front Due to the timing of the front coming through during max heating, some pooling of higher dewpoints into the 60s, and a rather strong mid level area of max winds may combine to produce a few storms that may become severe with the main concern being wind gusts. The best chance for stronger/severe storms will likely be in Southern New Hampshire who will see the sun last the longest along with the warmest temperatures. Total precipitation amounts will be light around a quarter of an inch. due to the fast progressive nature of these hit or miss showers. Any storm or downpour will be brief, lasting no longer than 15-20 minutes. Highs will be in the 70's and Lwr 80's with a breezy SW wind ahead of the approaching front.
The front quickly exits off the coast by late afternoon or early evening followed by gusty northwest downsloping winds which will aid in quickly clearing out skies. Canadian high pressure builds into the area with a return to cooler temps Wednesday night with lows ranging from the mid 40s in the mountains to mid 50s elsewhere.
The extended forecast looks to be pretty quiet...with two periods of note to focus on. The first will be a seasonably strong high pressure settling overhead Thursday-Friday. It is a favorable signal for sunshine and mild highs during the day in the Lwr-mid 70's, and strong radiational cooling during the evening...with temperatures below normal in the valleys. Many northern valleys will fall into middle 30s for a low early Friday morning...and frost is a possibility.
Sunshine will hold steady Friday with absolutely picture perfect weather. High pressure off the coast will keep sunshine in place for most of Saturday with highs climbing into the middle to upper 70's even nearing 80 in spots. Next event to keep an eye on will be a cold front to sag into the region from the NW. It will slowly move thru the forecast area...so Sunday may see a focus for showers and maybe a rumble of thunder over the course of much of the day. There is a potential for a wave of low pressure to develop along this slowing front to help enhance some of the precipitation which could come in the form of thunderstorms and the the potential for heavier downpours. There remain question on how dynamic this front will be and how heavy the rain will be. If the front moves faster, there will be less showers to contend with. If the front stalls, we could be contending with heavier rainfall potential Sunday. Stay tuned!