Extreme Weather Exam #2 Review

Fall 2017 GSI: Kim Frauhammer Things to Remember:

➔ Multiple Choice on scantron ◆ BRING No.2 PENCIL!!! ➔ 5-7 short answer (regular paper turn-in) Cloud Identification Cloud Identification

➔ Also special sub-sections of clouds: ◆ Lenticular ◆ Mammatus ◆ Altocumulus castellanus ◆ Cumulus humilis ◆ Cirrus uncinus ◆ Etc…. ➔ Know subsections of clouds gone over in lecture Name that cloud! a) Stratocumulus b) Altocumulus c) Cirrocumulus d) Cirrus Name that cloud! a) Altocumulus Castellanus b) Stratocumulus c) Cumulus Humilis d) Cumulus Global Circulation

➔ Hadley Cell at Equator where incoming solar radiation is greatest ◆ ITCZ ➔ Initiates sinking air at 30º NS and coriolis force turns (subtropical jet) ➔ Poles extremely cold, sinking air, where this sinking air meets warm air coming up from equator creates another circulation ◆ Strong temperature gradient combined with coriolis force turns and creates polar jet General Circulation

Side view ->

The movement of these jet streams NS with seasons influences much of our weather

We have many semipermanent highs and lows General Circulation

-Some oceans caused by Ekman spirals El Nino

➔ One such ocean current anomaly (ENSO) ➔ Weak warm current off western coast of S. America ➔ Occurs every 3-7 years, can last up to months ➔ Impacts all over the world, shifts jet streams, Highs/Lows etc. ➔ La Nina opposite, occurs half as often El Nino regular vs. active Geostrophic Flow + Friction

➔ Know these: ➔ They are all always acting at the surface Geostrophic Flow Winds at Surface

-Winds go CCW around a Low, CW around a High in northern hemisphere (opposite S. Hemi)

-Winds converge into a low at the surface, diverge around a high at the surface. Which direction is the wind blowing from? a) SW b) E c) W d) NE Winds at Surface Summary Where are strongest wind speeds at surface? Where we find the strongest pressure gradients. Air Masses Air Masses Characteristics of Fronts

➔ Stationary ◆ Front with no movement ◆ Winds parallel but opposite direction ◆ Variable weather ➔ Cold ◆ Cold, dry replaces warm, moist ◆ Clouds w/ vertical development ◆ Thunderstorms, squall-lines ➔ Warm ◆ Warm, moist unstable air overrides cold, stable air ◆ Horizontal cloud development with steady rain Fronts and Cloud Formation Characteristics of Fronts Cold vs. Warm Occluded Front

-Cold front catches up to warm front and cuts off warm air supply How to Locate a Front:

-Know these and how to apply them on a map Where’s the cold front? Shade in a swath Cyclogenesis

Know the stages and be able to explain. Role of the Upper Atmosphere

Direct Thermal Circulation

-Strong Temperature gradients at the surface, lead to strong pressure gradients aloft Role of the Upper Atmosphere ➔ As the temperature difference grows at the surface, the pressure gradient at the top of atmosphere gets steeper ➔ No friction force aloft, coriolis force turns and creates jet stream Upper Atmosphere

Be able to explain concept map Upper Atmosphere Adiabatic Process

Parcel dry, unsaturated air rises and sinks at the dry adiabatic lapse rate = 10ºC/km

Dewpoint rises at 2ºC/km when unsaturated

Parcel saturated air will rise at moist adiabatic lapse rate = 6ºC/km

Dewpoint rises at moist adiabatic lapse rate as well when saturated Flow over a mountain What is the temperature and dewpoint at Top and Bottom?

Thunderstorms Airmass T-storm Severe storm with tilted updraft