High pressure is in control today, but a storm system taking shape in the central US will exert influence on our weather during the next few days. Will it bring spring warmth or a spring chill?
Upper Level: Zonal upper level flow pattern develops in lieu of a departing trough. Ridging builds in mid-week out ahead of a trough in the central us. The trough passes by on Friday and ridging returns for the weekend.
Surface: Connecticut is on the northern periphery of a large area of high pressure anchored in the southern states. This high will retreat to our east tonight and tomorrow. A warm front sets up near our region late Wednesday in association with a developing low tracking from the central plains towards the great lakes region. As that storm tracks well to our north, its associated cold front will come through on Friday.
Uncertainties: One of the keys in the upcoming forecast is figuring out how far north that warm front sets up on Wednesday-Thursday. The are some indications that this boundary could slip south as a backdoor cold front and makes things colder for us. Fortunately that doesn’t seem threaten the south coast of New England but The NAM as well as the GFS and ECMWF do show the frontal boundary straddling the southern New England region during the Wednesday overnight period.
The GFS, however is slightly more north with the warm front boundary.
The 00z ECMWF actually has that boundary even slightly further south over central Connecticut. This slight difference in placement could have large ramifications on overall high temperatures as the gradient in new england this week is expected to be quite sharp.
Forecast: Right now, opting to stay mild with the forecast midweek. Showers and thunderstorms are then possible on Friday with the cold front passage followed by a cooler but sunny weekend.