Natty D- Ice Storms

Front 1

What are ice storms caused by?

Back 1

-caused the the accumulation of freezing rain

Front 2

Does freezing rain occur in large or narrow bands?
What will alter the location , intensity and duration of freezing rain?

Back 2

-it occurs in narrow bands
-small changes in temperature, wind speed and moisture content will alter the duration/location/intensity

Front 3

What is supercooled water? What do they result in?

Back 3

-water doesn't necessarily freeze at 0 degrees
-supercooled= water remains in a liquid state below temperatures of 0 degrees

-as a result, when it come sinto contact with a surface it freezes onto that surface
-causes freezing rainstorms

Front 4

What are the weather conditions for an ice storm?
What is the most common?

Back 4

-north of a warm front, west of surface cyclone
-north of coldfront in a cold-air dome associated with high pressure cyclone

Most common is in between low and high pressure system
-cold, dense air comes form north and lies near surface
-warm, moist air comes from south and flows over cold air

Front 5

What is the vertical temperature structure during an Ice Storm?

Back 5

-as you go up in the atmosphere, the instead of decreasing, the temperature will increase. This layer is called inversion

-then farther up in the atmosphere, there will be cooling of air with height

Front 6

how does an inversion form?

Back 6

-warm, moist air from south flows over a dome of cold, dense air from the north
-precipitation forms as snow, but it will melt in the deep, warm layer of air
-once water falls into the cold near-surface layer, it is supercooled
it will then freeze on impact with the surface

Front 7

What makes an ice storm so severe?

Back 7

-persistence (lasts for hours)
-intensity (how fast it precipitates)
-phase (supercooled water)
-location

Front 8

What was so special about the ice storm of 1998 in Montreal?
What were the effects?

Back 8

-it has a lot of persistence, usually ice storms last for a couple of hours, yetk kthis one lasted for nearly 5 days
-warm+moist air usually originates from Gulf of Mexico, but in this case it came from eastern Atlantic ocean
-incredible amounts of precipitation+intensity

effects:
-fatalities due to hypothermia
-mass power outage
-residents forced to into mobile living
-millions of trees downed
-major economic damage -> power+telephone lines, utility poles, transmission towers
-livestock losses
-agricultural devestated
-infrastructure of electrical grid had to be rebuilt

Front 9

Why is Montreal particularly vulnerable to ice storms?

Back 9

-due to topography that surrounds region
-north-eastern winds transport cold+dense air from Gulf of Saint Lawrence
-cold air gets trapped in saint lawrence valley
-

Front 10

What are some mitigation techniques for ice storms?
What are safety measures if power+heat are lost?

Back 10

-listen to media for freezing rain warning

safety:
-close off uneeded rooms, eat+maintain energy for heat+hydration, wear layers, use fire safeguard+properly ventilate