Chilly weekend in Northeast could include some snow
Updated Apr 14, 2021 7:25 PM EST
Wednesday was a nice mid-April day in the middle of Pennsylvania. There was some sunshine at times, and temperatures climbed well into the 60s. There's nothing wrong with that picture.
The surface map consists of a variety of weak and features that are not well organized. There are a few troughs, marked by thin black lines, and a few high and low pressure areas, none totally dominant. Looking at the black arrows, we can conclude that the prevailing wind was from northwest to southeast.
The satellite radar composite showed several areas of precipitation. One affected the area from Delaware to Mississippi. The regional radar picture below the radar satellite composite isolates the eastern rain area.
The forecast map for Thursday at 2 a.m. shows a low pressure area centered near the Ontario-Quebec border with some snow on its north side. The rainfall area we looked at just before has now consolidated along the coast. The blue dotted line that we often associate as being near the snow/rain line in winter runs from South Dakota to central Illinois to western New York. At this time of year when it is typically warmer than winter, the snow/rain line is more likely to be associated with one of the blue dotted lines north of the wintertime boundary. Why? Those lines represent temperatures between the ground and about 3 1/2 miles overhead. You can get the same value when it is very warm at the ground and very cold aloft as when it is chilly at the ground and aloft.
The following map for Thursday shows the air mass getting somewhat colder over the Northeast. It looks like many areas will have a chilly and cloudy day along with periods of rain.
On the Friday afternoon map below we see a low pressure area along the New England coast and what looks like a solid area of snow over central New England. It also looks snowy from the eastern Rockies into the central Plains.
Saturday also may be rather cloudy over the northeastern corner of the country with a chill in the air, but it looks nowhere near as stormy as Friday.
Looking at the Sunday map we see that this is not a situation where a storm leaves, and it simply clears up with springtime warmth soon to follow. In fact, it looks chilly and perhaps dull, damp, dreary and drippy with drizzle. (Darn)
The Monday and Tuesday maps suggest a little bit of warming across the Middle and North Atlantic states as a new cold front dropping southeastward from the Upper Midwest.
As for the snow, the GFS predicts a heavy, wet snowstorm in the higher terrain of New England. Some wet snowflakes could be seen in New York City, Providence and Boston, but the current guidance does not suggest significant accumulations in those cities.
However, the printout for Pittsfield, Massachusetts, in the Berkshires shows about an inch of water during a time when the surface temperature will be below 34 degrees F. If snow falls lightly at that temperature, it will melt on paved surfaces. However, if heavy snow falls, it can accumulate. I remember a heavy, wet snowstorm in Philadelphia that dumped more than a foot of snow with the official air temperature of 33 degrees during most of the storm. That storm dropped a state record 50 inches of snow near the Reading-Morgantown exit of the Pennsylvania Turnpike. The temperature was just below 32 during most of the storm at that location.
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Weather Blogs / Northeast US weather
Chilly weekend in Northeast could include some snow
Updated Apr 14, 2021 7:25 PM EST
Wednesday was a nice mid-April day in the middle of Pennsylvania. There was some sunshine at times, and temperatures climbed well into the 60s. There's nothing wrong with that picture.
The surface map consists of a variety of weak and features that are not well organized. There are a few troughs, marked by thin black lines, and a few high and low pressure areas, none totally dominant. Looking at the black arrows, we can conclude that the prevailing wind was from northwest to southeast.
The satellite radar composite showed several areas of precipitation. One affected the area from Delaware to Mississippi. The regional radar picture below the radar satellite composite isolates the eastern rain area.
The forecast map for Thursday at 2 a.m. shows a low pressure area centered near the Ontario-Quebec border with some snow on its north side. The rainfall area we looked at just before has now consolidated along the coast. The blue dotted line that we often associate as being near the snow/rain line in winter runs from South Dakota to central Illinois to western New York. At this time of year when it is typically warmer than winter, the snow/rain line is more likely to be associated with one of the blue dotted lines north of the wintertime boundary. Why? Those lines represent temperatures between the ground and about 3 1/2 miles overhead. You can get the same value when it is very warm at the ground and very cold aloft as when it is chilly at the ground and aloft.
The following map for Thursday shows the air mass getting somewhat colder over the Northeast. It looks like many areas will have a chilly and cloudy day along with periods of rain.
On the Friday afternoon map below we see a low pressure area along the New England coast and what looks like a solid area of snow over central New England. It also looks snowy from the eastern Rockies into the central Plains.
Saturday also may be rather cloudy over the northeastern corner of the country with a chill in the air, but it looks nowhere near as stormy as Friday.
Looking at the Sunday map we see that this is not a situation where a storm leaves, and it simply clears up with springtime warmth soon to follow. In fact, it looks chilly and perhaps dull, damp, dreary and drippy with drizzle. (Darn)
The Monday and Tuesday maps suggest a little bit of warming across the Middle and North Atlantic states as a new cold front dropping southeastward from the Upper Midwest.
As for the snow, the GFS predicts a heavy, wet snowstorm in the higher terrain of New England. Some wet snowflakes could be seen in New York City, Providence and Boston, but the current guidance does not suggest significant accumulations in those cities.
However, the printout for Pittsfield, Massachusetts, in the Berkshires shows about an inch of water during a time when the surface temperature will be below 34 degrees F. If snow falls lightly at that temperature, it will melt on paved surfaces. However, if heavy snow falls, it can accumulate. I remember a heavy, wet snowstorm in Philadelphia that dumped more than a foot of snow with the official air temperature of 33 degrees during most of the storm. That storm dropped a state record 50 inches of snow near the Reading-Morgantown exit of the Pennsylvania Turnpike. The temperature was just below 32 during most of the storm at that location.