BOMB
CYCLONE - GEOGRAPHY
News:
Deep freeze grips U.S. as
winter 'bomb cyclone' looms ahead of holiday weekend
What's
in the news?
●
A deep
freeze enveloping most of the United States early on December 23, 2022,
combined with a massive winter storm
brewing in the Midwest to leave two-thirds of the nation under extreme weather alerts, confounding
travel plans for millions of Americans.
●
Heading into the Christmas holiday
weekend, the looming storm was forecast to develop into a "bomb
cyclone," unleashing heavy, blinding snow from the northern Plains and
Great Lakes region to the upper Mississippi Valley and western New York.
●
Numbing
cold intensified by high winds was expected to extend
as far south as the U.S.-Mexico border.
What
is a Bomb cyclone?
●
The term is used by meteorologists to
indicate a mid-latitude cyclone that
intensifies rapidly.
●
Storms can form when a mass of low-pressure air meets a
high-pressure mass. The air flows from high pressure to low, creating
winds.
●
A bomb cyclone happens when atmospheric pressure in the middle of
the storm drops at least 24 millibars over 24 hours, quickly increasing in
intensity.
●
This quickly increases the pressure
difference, or gradient, between the two air masses, making the winds stronger.
This process of rapid intensification is called bombogenesis.
●
The lower the pressure, the stronger the
storm.
Conditions
favouring Bomb Cyclone:
●
The conditions for a bomb cyclone had been
met over the Great Lakes, where frigid Arctic air from the meandering polar vortex met very warm air to the east.
●
As the area where the two air masses meet,
called the Arctic front, moves
northward and eastward, conditions for bombogenesis should continue moving as
well.
How
it works?
●
Deep drops in barometric pressure occur
when a region of warm air meets one of cold air.
●
The air starts to move and the rotation of
the earth creates a cyclonic effect.
●
The direction is counter clockwise in the Northern hemisphere leading to winds that
come out of the northeast.
Does
Bombogenesis affect only temperate regions?
●
Bombogenesis can take place in both tropical and extra-tropical cyclones.
●
Tropical cyclones can also undergo rapid
intensification, which is a particularly unnerving development, especially when
it occurs near landfall.
●
An example of a tropical cyclone
undergoing bombogenesis is Hurricane Charley in 2004.
Impacts
of Bomb Cyclone:
●
Several major impacts will include strong winds, beach erosion and coastal
flooding especially with high tide.
Why
is the US more vulnerable to Bomb Cyclones?
●
The corridor off the East Coast of the U.S. is notorious for bombogenesis events,
particularly in recent years.
●
Frequently, nor'easters are weather bombs
due to cold air surging southward from Canada combined with the warm ocean
waters of the Gulf Stream.