Oct 3, 2016 11:16 PM
NH1 First Alert Weather: Sunshine Returns, Hurricane Matthew Thoughts
NH1 Chief Meteorologist
High pressure will continue to build into the region from the northeast on Tuesday. Cloudy conditions to start will gradually give way to increasing afternoon sunshine from NE to SW as the day progresses. Highs will range from 60 to 65 degrees by afternoon, warmer inland and coolest at the coast. Fair and cool weather is then expected Tuesday night with a good chance of ground fog development and lows dropping into the Lwr 40's overnight. High pressure at the surface and aloft will keep conditions dry and calm Wednesday through Friday. Afternoon highs will begin in the 60s and increase into the lwr-mid 70s by Friday. Nighttime lows will be in the 30s and 40s with fog development in the valleys.
Hurricane Matthew is an absolute Monster in the Caribbean with very little chance of this losing much steam. Matthew will be holding onto Catergory 3/4 status right through the Bahamas before making a close pass to the east coastline of Florida where it will likely remain just about 50 miles offshore. There seems to be a growing consensus among the computer models that a trough crossing North America will pick up Hurricane Matthew over the Carolinas this weekend and pull it northward. Even the infamous Euro model is coming on board with this idea, though it continues to be further to the east and staying out to sea scenario more than any of the other models. I believe it is leading the long range outlook as usual. Because of a westward trend to the models Monday, there is a growing consensus which gives a little more confidence towards the more inward track solution with more of an impact across the Northeast, with Matthew tracking north from the Carolinas into the vicinity of New England. I am still not ready to completely buy in just yet. The Euro model has a good history of nailing the long range and I want to continue to watch the trends. By Wednesday we will know what we should expect for the weekend...hit or miss.
It has been said that most droughts end in floods, and if the American (GFS) solution pans out then this will be our chance. Some models are printing out estimates ranging from 4-8" of rainfall. This would be great for the drought, but flooding would be a real concern. We have increased precipitation chances Saturday night and Sunday as this will be the time we would be most likely to see any impacts.
A key factor in where the storm may track will be revealed in how quickly the storm moves through the Bahamas. The quicker it makes northward, the more easily it will be picked up by the trough and thus the further west it will make its track northward along the East Coast. A slower track through the Bahamas will slightly delay it being picked up by the trough, allowing the trough to sling the storm northeast and out to sea with minimal impacts to our area. So this will be one factor we look for in the coming days to help determine whether our area will be impacted.
We will continue to monitor the latest forecast tracks from the National Hurricane Center. Matthew will likely NOT be tracking through New England, but even with a track near the benchmark, the biggest impact will be the heavy rainfall. With its origins in the deep tropics & a cold front helping to squeeze that moisture out, several inches of rain would be possible in a short amount of time around late Saturday night into Sunday. With the ongoing drought, river levels will already be starting out quite low, but this amount of rain would pose a risk of flash flooding and river flooding no matter how dry we have been. In addition, the storm may still have a strong pressure gradient associated with it, bringing stronger winds to the area as it moves through. Cannot rule out a wind advisory type scenario occurring, especially behind the storm. Surf will also be high along the beaches, though the fast movement of the system may prevent the largest waves from developing. Models are in agreement that behind the front which moves through this weekend it will be getting colder. Depending on how the system tracks, there could be enough cold air pulled down out of Canada to produce some upslope snow showers in the mountains.