Lab 10November 20th, 2013

Snowy Side of ThingsSnowfall normally occurs on the NW side of Low Pressure Systems

Why? While moisture is fed into the storm, counterclockwise winds usher in cold air in this region, supporting snowfall!

Idealized winter storm:

The Aftermath Often we can see the remnants of a significant

winter storm (images taken from NOAA/ERH)

Surface temperature of regions with snow compared to surrounding areas? (Hint: Think albedo)

Winter Precip Type

What Kind Of Precipitation??????

SNOW!!!!!

What Kind Of Precipitation??????

SLEET!!!!!!!!!

What Kind Of Precipitation??????

FREEZING RAIN!!

What Kind Of Precipitation??????

RAIN!!!!!!!!

Lake Effect - Revisited

Remember, lake effect occurs when cold air moves relatively warm lake waters.

Great lakes tend to freeze as the winter progresses.

The deeper the water, the longer it takes to freeze…why?

Based on annual average snowfall and the ideas above, which great lake is likely the deepest?

16.6

a. No need for calculation, just explain your answer

Lake Effect:Unstable Lower

Troposphere Assume water surface temperature is 5 deg.

C What do you assume the air temperature is

just above the water’s surface? 5 deg C (although it may be just a little colder)

If the temperature at 1600 m is -15 deg. C, what is the stability of the lower troposphere? 5 - (-15) = 20 deg. C per 1.6 km 20 deg. C / 1.6 km = 12.5 deg. C / km Unstable!

Wind - Chill• The temperature it “feels-like” due to

the flow of air on exposed skin.

Lab Assignment 16.1 (a, b)

16.3

16.6 (a, b, c, d) (no calculation necessary for part a, just very brief explanation)

16.7 (a, b, c)

16.9 (a, b)

16.11 (a)

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