We are facing one of the coldest patterns we have seen this spring and it comes right at the beginning of our transition to more summer-like weather that usually occurs in May! Above, the surface map shows our current rain storm we are seeing today, which is the precursor to our colder weather ahead.
As shown on the second image, an area of anomalously low heights and pressure breaks off over the Northeast over the weekend. This becomes a cutoff low that looks to stick around with us for the week and into Mother’s Day weekend. This pattern is typical of what we tend to see in the beginning of the Meteorological Spring Season (March 1st-May 31st).
Above show the typical weather types we see during the beginning of March (labelled as k = 1, 3, 4 and 6). Typically the pattern shows an area of low pressure over the Great Lakes pushes Southeast into the Eastern Seaboard. This Low can then cutoff and cause a secondary area of low pressure to form in Northern New England. These two areas of low pressure influence the weather over the region for a span of 2-5 days before finally pushing offshore into the Atlantic as High pressure from the Midwest moves into the region. (k=4 to k=3 to k=6 to k=1 is the typical pattern).
The above images show the MSLP (black lines), 500 hPa heights(yellow lines), 850 hPa winds, and temperature anomalies (blue = colder than average, red = warmer than average). This shows that for the majority of the pattern, the area can be expected to see colder than average temperatures, with the coldest occurring when the pattern is at its climax (as the two lows over Northern and Southern New England contain influence over the region). Then temperatures return to normal and slightly above normal as the pattern loses its influence over the region and high pressure from the west moves in.
So what can we expect in terms of precipitation with this pattern? Well usually the onset period of this pattern will see the most rain for the New England Region. However, all of the weather types have some precipitation over the region, which means that there could be the chance throughout the pattern for showers to occur on any of the days.
The good news is that this pattern usually lasts a max of 2 weeks on average, so we can look forward to a return to more seasonable and possibly warmer weather by the middle of the month!