Calm weather has settled into the area during the middle part of this week in the wake of a cold front, but gusty winds have ramped up over the last 12 to 24 hours with a tightening pressure gradient over the area. Blustery northwest winds led in a surface high pressure on Wednesday Night, as a low pressure system deepened well off to our north and east. The northwest winds and very low humidity are leading to concern for brush fire spread throughout the area. Subsequently, the National Weather Service has issued a Red Flag Warning for much of the area — save for Long Island, where higher humidity values are present near the coasts.
A Red Flag Warning is issued by the National Weather Service when high winds and low humidity are expected to make conditions favorable for dangerous and rapid spread of brush fires if ignition occurs. Despite the concern for fire spread, pleasant weather will continue — albeit a bit cool of this time of year. Highs in the lower 60’s will be common on Thursday and Friday before a disturbance approaches with a period of rain expected Friday Night.
Ejecting essentially from the Central United States into the Northeast on Friday, the disturbance in the mid and upper levels will force the development of a surface low pressure system which will track near the area Friday Night. Increased lift for precipitation as well as increasing moisture (a big change from the very low dew points on Thursday) will allow rain to become steady for a period of time Friday Night. But the progressive mid and upper level flow will push the system northeast of our area before any widespread heavy rains can occur.
But while we may avoid the heavy rains with the surface low tracking to our northeast, a secondary disturbance over the Great Lakes will slide eastward and — according to most forecast models — phase with the lead disturbance over New England and the Gulf of Maine. While this may not seem like a big deal initially, it will only act to re-enforce the cooler than normal pattern. Cold mid level temperatures will slide southeast towards New England and while we may avoid steady precipitation, the cooler marine air will be allowed to take over the areas weather.
With mid level ridging and higher than normal height anomalies spreading from Greenland into Central Canada, enough bucking of the mid level flow causes concern for additional phasing and cutoff lows in the next 2 weeks. The blocking pattern to our north, which we often look for in winter, can help aid in these phases which ultimately will lead to more unsettled weather for our area. Forecast models are already strongly hinting at a Central US phased cutoff upper level system, which could drift eastward and bring rain into our area for a prolonged period during the middle to end of next week.