Aviation Meteorology Final

Standard temp Atmosphere

15 C, 29.92 Hg or 1013.2 mb

Standard lapse rate

-6.5 C/km

Tropopause height

11 km

Pressure at FL050

850 mb

Pressure at FL180

500 mb

Pressure at FL300

300 mb

Pressure change with altitude (inHG)

1 inHg per 1000 ft

Define Pressure

Force per unit area

How does temp affect pressure change with height

Cold air = pressure decreases FASTER with height
Warm air = Pressure decreases SLOWER with height

High to low, Look out below

If pressure decreases enroute, you are LOWER than your altimeter indicates

what forces balance to create geostrophic wind

PGF and Coriolis force

What strengthens geostrophic wind

stronger pressure gradient

Geostrophic wind directions around highs

Clockwise

Geostrophic winds around lows

Counterclockwise

Two reasons wind is NOT geostrophic

Friction, curved flow

Subgeostrophic winds occur where

Around Lows

Supergeostrophic winds occur where

around highs

What creates jet streams

Strong horizontal temperature gradients tilting pressure surfaces

Stronger Temperature gradient =

stronger winds aloft

Convergence and Divergence

Winds flow TOWARD a point, Winds flow AWAY from a point

Cyclonic and Anticyclonic flow

Cyclonic is counterclockwise, Anticyclonic is clockwise

Cyclonic and anticyclonic shear

winds increase cyclonic or anticyclonic rotation across a distance

Speed convergence and divergence

Convergence is fast to slow winds, Divergence is slow to fast winds

cA

cold, dry, stable, ice

cP

Cold, dry, stable

cT

Hot, dry, stable aloft, unstable at surface

mP

cool, moist, unstable

mT

Warm, moist, unstable

Stationary front

boundary not moving

Occluded front

Cold front overtakes warm front

Cyclonic Life cycle

Stationary front, frontal wave, open wave, mature (initial occlusion), advanced occlusion, cut off cyclone

Radar reflectivity dbz chart

Light - <30
Moderate - 30-40
Heavy - 41-50

Extreme - >50

3 stages of a thunderstorm

Cumulus, mature, dissipating

LCL

Where parcel temp and dewpoint lines meet

CCL

Level where surface air becomes saturated if heated

LFC

level where parcel becomes warmer than environment

EL

Level where parcel becomes cooler than environment again

LI formula

Environmental temp at 500 mb - Parcel temp at 500 mb

CAPE categories

Weak - <1000
Moderate - 1000-2500

Strong - 2500-4000

Extreme - >4000

Head/Tailwind formula

HT = WS * Cos(a)

Crosswind formula

CW = WS * Sin(a)