Too Many Fronts

OKX Base Reflectivity Courtesy of WeatherTap, Click to Animate

This is pretty cool stuff for a weather geek. Take a look at the echoes racing west across Long island Sound. That is a backdoor cold front with a strong wind shift behind it and rapid temperature drop. The wind at Bridgeport is north at 15 mph and the temperature is 78º while the wind in Groton is southeast gusting to 32 mph and the temperature is 62º!

There’s another front on there and that a sea breeze front that has developed basically over New Haven Harbor and extends northeast into North Branford, Durham, and Killingworth with southerly winds behind it and northerly winds ahead of it.

One of the reasons the backdoor front has taken on a “C” shape is that less friction over the water has allowed the winds to be faster over the Sound than over land which is effectively bulging the front west in the water.

The echoes to the west over New York are showers falling from a mid level cloud deck that are evaporating before reaching the ground.

Advertisements

3 thoughts on “Too Many Fronts

  1. Interesting !
    I have a question regarding the way tornado strength is determined. I note that wind speed is discussed as a barometer of strength, however it doesn’t appear to take into account the torque and suction forces inherent in the rotation. Or does it? Does the Enhanced Fujita scale take that into account and that is why it is “enhanced” ? It seems to me that stating that the tornado in MA this week had 160 mph winds (which hurricanes can have and do not produce the same kind of damage per se) does not do justice to the extreme force and damage that I had witnessed in Monson today on a drive through. Seeing that path up and over the ridgelines certainly dispells the myth that they can’t travell over hilly terrain….amazing damage. surreal.

    • Wind is caused when air blow from high pressure to low pressure. In a tornado the pressure gradient is exceptionally tight with very low pressure in the vortex and higher ambient pressure outside. There is some vertical component to the wind in a tornado (what people would think of as suction) but it’s not nearly as significant as the horizontal component of the wind in this case up to 150 or 160 mph.

      160 mph winds will destroy a building, no doubt about it, and frequently in a hurricane winds of this magnitude are observed offshore but tend to diminish rapidly inland so the vast majority of hurricanes (even strong) never produce winds of this magnitude 5 to 15 feet off the ground.

      The enhanced Fujita scale is just an update to the previous scale that uses damage indicators to estimate wind strength.

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s