Weather with Bill Evans

Good Day On This Tuesday Nov. 30, 2021 A weak upper disturbance passes through the local area this afternoon and into this evening. High pressure then briefly moves across the eastern seaboard on Wednesday, followed by a quick moving frontal system Thursday into Thursday night. High pressure briefly returns Friday before a series of weak low pressures and frontal systems move across this weekend into early next week. High pressure will continue to move south of the area through early this morning. A weak upper disturbance over the Great Lakes will move quickly east producing some scattered flurries and sprinkles today, with only trace amounts expected. Weak high pressure will be left in the wake of the shortwave. Dry for the late night hours with winds under 10 mph. Temperatures today will be in the 40s across the area with lows tonight in the upper 20s to mid 30s. Wednesday will be dry with moderating temperatures to near seasonable levels in the mid and upper 40s. High pressure will be centered over the southeast and ridge up into the northeast. A shortwave will likely be approaching from the west and SW flow aloft will bring increasing clouds through the day. A progressive pattern will persist through the upcoming weekend and early next week. There are a few frontal systems and shortwaves that will move across the northeast, but no significant impacts are expected at this time. The deterministic models and ensembles offer some agreement this week, but start to diverge this weekend into early next week. The differences arise with timing of energy within the progressive flow and with any associated amplification. A warm front then approaches Wednesday night. This warm front should lift north of the area through Thursday. The aforementioned shortwave axis should also shift offshore Thursday morning.The warm front and associated warm advection should be enough to bring some light rain showers near the coast and rain/or snow showers further inland late Wednesday night into early Thursday morning. The pattern with this system does not support significant precipitation and also does not support any wintry precip with parent low pressure north of the Great Lakes. Temperatures may actually rise overnight Wednesday into Thursday morning limiting any wintry precip inland as well. Precip chances diminish Thursday as the warm front and shortwave axis move north and east. This will set the stage for a mild day with temperatures warming into the upper 40s inland and lower to middle 50s near the coast. It will also turn breezy with SW winds around 15 mph gusting 20-25 mph, especially near the coast. The associated cold front will move through Thursday night. There continues to be limited moisture to work with and a higher probability that the actual cold front will move through dry with just mostly cloudy conditions. A fairly strong low pressure moves towards southeast Canada and the Maritimes by Friday morning. Cold advection will take place behind the cold front and the region looks to lie within a decent pressure gradient between the low and high pressure to the west. A breezy NW flow should occur Friday. Despite the cold advection, the downsloping flow should help temperatures reach seasonable levels in the middle and upper 40s. The next shortwave quickly approaches Friday night into Saturday. A general consensus of the global models and ensemble means indicates this system to be flat and largely pass to our north. There should be a weak surface reflection with a weak low and frontal system passing by on Saturday. Have kept PoPs at slight chance and low end chance as not seeing much lift and/or dynamics to support measurable precipitation at this time. High pressure briefly returns on Sunday before another potential frontal system and low pressure early next week. The modeling has been over amplifying systems in the extended, especially close to a week out. Followed the NBM PoPs for now, but would not be surprised to see changes to a flatter less amplified solution given the recent model biases. Winds and seas diminish early this morning with sub-advisory conditions lasting through the day. Westerly winds pick up tonight, and SCA conds will be possible on the ocean after midnight. Seas on the ocean east of Moriches Inlet may be close to 5 ft early Wednesday morning. Otherwise, sub-SCA conditions are expected Wednesday and Wednesday night. SCA conditions are likely on all waters later Thursday into Thursday night ahead of an approaching cold front. SCA conditions are then probable on the ocean and possibly eastern LI Sound and Bays in a relatively strong NW flow behind the cold front. Conditions should fall below SCA levels on Saturday.