As if the East Coast needed more problems, on the heels of Sandy‘s departure now comes the arrival of a Nor’easter this week.
We’ve all heard the term, but what does it mean? A Nor’easter is a strong area of low pressure that tracks up the East Coast of the United States. It’s moisture is supplied from the Atlantic Ocean, while cold air filters into the system from the north. It typically produces strong, gusty winds from the northeast as the low pressure area moves up the East Coast. You can click here to understand a little more how these systems form and work.
People are already asking how will this compare to Sandy? In short, no comparison. Sandy was a warm-core system, a hurricane that meshed with and transformed itself into a wintertime low pressure area or strong mid-latitude cyclone…a cold-core system. It was the perfect storm, a superstorm of sorts. This Nor’easter is not tropical, but it will be strengthening this week as it moves from Florida’s Gulf Coast, to the Mid-Atlantic, and out over the north Atlantic Ocean.
As I examine our computer forecast models, I can see an upper level low forming over Arkansas Monday evening. The accompanying surface low forms and deepens over Florida’s Gulf Coast by Tuesday morning. By Tuesday evening, the low has moved over the ocean off Florida’s east coast with a pressure of 1009 millibars…that’s 29.79″ of mercury for those of you with barometers. By Wednesday morning the strengthening system has dropped to a pressure level of 999 millibars, or 29.50″ of mercury. Rain, wind, and strong, pounding erosional surf is already plaguing the Southeast and Mid-Atlantic coasts. By Wednesday evening, the low further deepens to a pressure level of 986 mb, or 29.11″ of mercury. Heavy rain, wind, and erosional surf, and dangerous rip currents continue to threaten the Mid-Atlantic states.
Thursday morning this Nor’easter is producing widespread 40 to 50 mph winds, heavy rain, heavy snow across the Appalachians, coastal flooding, and erosional surf across much of the Northeast and New England area. The low has deepened to a pressure level of 980 millibars, or 28.93″ of mercury on the barometer, which is the same pressure level as a category one hurricane. The forecast models don’t have this system pulling away from the United States until later on Thursday as it moves into the north Atlantic Ocean.
For those of you that have an interest in seeing what we see as meteorologists with this system, here are a series of links you might find interesting. Here is a computer forecast model (what we call the GFS) from Tuesday evening. Notice the outline map of the United States. All of the purple is forecast precipitation, while the blue/green is heavier precipitation just off the Southeast Coast. Note also the “L” or low pressure off Florida’s east coast. Yes, we also have some light purple over the Great Lakes…that’s the cold front that will slide through our area Tuesday evening/Wednesday morning and give us a few showers.
By Wednesday morning the forecast model shows the system moving into the Mid-Atlantic. It really cranks up by Wednesday evening with the low located just off-shore of Virginia. By Thursday morning, the system is clearly affecting most of the Northeast and New England area with all the typical attributes of a Nor’easter. Unlike Sandy, Michigan will NOT be impacted by this storm.
It’s always possible this storm may track a bit further off-shore and spare many of the areas hit just last week from Sandy, but that’s not the most likely scenario. Forecasters up and down the East Coast are already moving into storm mode and this looks to be the second of a one-two punch for many areas that are still recovering from Sandy the superstorm.
The attached image is from NOAA and is satellite imagery (water vapor) from the classic 2007 Nor’easter that hit the Northeast and New England areas on April 15 and 16th. Note the classic “comma head” shape and scope of these systems. For more on our weather here in West Michigan, simply click on to www.fox17online.com/weather. Have a pleasant first week of November.