1. Part 5
12/1/2018

2. Week 16, 17, 18 and 19 The Atmosphere
Modules 3, 4, 7 and 8 in AP
The study of the Air and the Atmosphere and how we measure them
Movement of the Atmosphere - Air Masses, Winds and Storms
Weather Prediction
Next test: Week 19 T Jan 23/25 - covers the atmosphere and hydrosphere
Week 20 A Jan 30 - I will be away - analysis exercise
U of IL - Wx Course
Lyndon State Course
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3. Current Weather Review 
Radar/Sat
US Radar
US Radar NWS
Goes Sat Page
US Sat IR
NRL Sat
US Sat Vis
NY VIS
Sfc Analysis NWS
Surface Plots
Surface 12 Hour Fcst
Surface 24 Hour Fcst
Surface 36 Hour Fcst
Surface 48 Hr Fcsts
Emergency
CURRENT SVR Wx RADAR
National Weather Situation Page  
Severe Weather Alert Link
Your Local Forecast
Local Fcsts
Rome NY 
 43.23°N 75.46°W 
Rome Griffiss Airfield
Lat:   Lon:   Elev: 504 ft Lat/Lon: 43.23°N 75.46°W   Elevation:482  
BGM Discussion 
Wx Maps
NAM
GFS
1. GFSx -Upper
2.GFSx-MRF- Precip
Long Range NWS Model
ECMWF
CPC
Datastreme
Climo
SYR CLIMO
CLIMO STAT CNY
ALB CLIMO
Other
NASA Solar Science
Solar-Sun Spot-Space-Wx
Sun & Moon Rise & Set Tables
Moon Phases
Your Sky Start Charts
Tides Maine
NOAA Space Wx
Forecast Central
12/1/2018

4. Module 8 Forecasting the Weather that Influence the Weather
12/1/2018

5. Prep Questions Week 16 Week 17 Week 18 Week 19
(1) What role does the sun play in causing seasons and the weather?
(2) What is the composition of the air?
(3) What is the role of each component?
Week 17
(1) What are the 5 layers of the atmosphere?
(2) What is temperature?
(3) What is Ozone hole?
Week 18
(1) What factors influence the weather?
(2) What are the weather elements?
Week 19
(1) What are the factors that cause precipitation?
(2) What are the differences and common characteristics of a thunderstorm, tornado, hurricane and a nor'easter low pressure system?
12/1/2018

6. 12/1/2018

7. How to Make a Weather Forecasts
Makes observations
Local Surface and Soudings
Radar, Saltilite,Weather Maps (Sfc and Upper air)
Look at trends - how fast systems are moving, what type of weather is moving to the area over what period.
Look at model forecasts - words and maps
Make forecasts
Go Over a Case Study
12/1/2018

8. Wind Basics Wind is the large scale motion of the air.
The direction of the wind is described by the direction it is blowing FROM (meteorological angle). For example, a southerly wind means a wind blowing FROM the South. The wind direction is often reported by its "compass" direction, for example:
90° - wind from the east (easterly)
180° - wind from the south (southerly)
270° - wind from the west (westerly
360° - wind from the north (northerly)
Note: "ward" means "moving to". Southward means moving toward the south.
Wind Speed on weather maps is usually measured in nautical miles per hour (knots). This is close to miles per hour, the conversion being 1 knot = 1.1 miles per hour. The number of barbs on the "wind flag" gives the speed of the wind. See inside back cover of your text for detailed examples.
Wind is depicted on weather charts using a shaft to show the direction of the wind (from), and barbs to show speed. A half barb is 5 knots, a full barb is 10 knots, and a filled in triangle barb is 50 knots.
12/1/2018

9. Force that Create Wind Review of Basic Motion Physics:
Velocity of an object is combination of speed and direction
  Acceleration is rate of change in velocity. Can be either change in speed (either increase or decrease) or change in direction. If forces on an object are NOT in balance, then the object will accelerate. If the forces are in balance on an object so NET force is 0 then object's velocity will not change.
The Pressure Gradient Force (PGF) – caused by a change in pressure/change distance). It is a real force that is NOT affected by wind. PGF is what causes wind. Note: "Δ " means "change in". PGF is the force that initiates the winds. If there is a pressure gradient (difference in pressure over some distance or PG) there MUST be a PGF. PGF will cause air motion – wind (described by the letter "V" in some equations) – from higher to lower pressure.
An example of PGF is the airplane wing. If one side of an object (airplane wing) experiences different pressure than the opposite side, forces from the pressure won't cancel. Lift occurs which causes the wing, and hence the plane, to rise.
There will be a net force from higher pressure to lower pressure. There is PGF is in both horizontal and vertical. On a weather map the closer the isobars (lines of equal pressure) are together, the stronger the PGF
The horizontal PGF is always directed from high to low pressure. So it is into a low pressure and out of a high pressure system. The winds start off in that direction. Given enough time and distance, Coriolis Force (CF) will deflect the winds. (More on this later.)
The vertical PGF is always up. There tend to be a vertical pressure balance with the force of gravity called the hydrostatic balance. The except is in extreme conditions such as in a tornado)
12/1/2018

10. PGF
PGF
PGF
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11. Forces that show up after the air is in motion.
The Coriolis Force (CF) – Show up after the air is in motion. Caused by movement on the rotating earth.. The actual magnitude of CF is the product of the curvature of the earth (called the Coriolis Parameter) and the speed of the wind (or any object). CF is not possible at the equator.
Centripetal (in)-Centrifugal (out) Forces (CentP, CentF) also show after the motion of the air is in motion. These forces results when there is curved or circular wind flow (V2/r) r = radius of curvature
Friction (Fr)– result anytime the wind makes contact with a surface. Always slows the winds down and deflects wind slightly to lower pressure.
CF, CentP, CentF and Fr ALL are result after there is a wind and are a function of the wind speed. Only PGF is independent of the wind speed. CF
CentP
CentF Fr
12/1/2018

12. Basic Wind Balance
The geostrophic wind balance (Vg) is the basic wind balance of  the wind
   PGF = CF.
When PGF = CF (or we assume this to be true) we call the wind the Geostrophic Wind or Vg.
PGF and CF are usually close to being in balance.
They act in opposite directions.
PGF is always to the left of the wind motion.
CF is always to the right of the direction of motion.
This means that in the northern hemisphere: the wind blows along lines of constant pressure, with lower pressure to the left. Ths leads to Buys Ballot Law which basically states "wind at your back lower to your left".
Above the planetary boundary layer (PBL - about 3000 feet - surface friction layer) friction is small. PGF and CF tend be very close to being in balance above the PBL. So V ≈ Vg above 3,000 feet altitude.
There are three factors that modify the geostrophic balance and cause an "Ageostrophic" component to the real wind.
(1) Time and Distance – it takes time (6 hours) and distance (a few hundred miles) for the CF to create the balance with the PGF. This means that localized and short-term winds are NOT Geostrophic.
(2) Curved Flow - Curved flow causes Centripetal and Centrifugal accelerations that slow the winds below Vg around a low and speed up the winds more than Vg around a high.
(3) Friction – Friction always slows the winds down and results in a deflection of degrees to lower pressure Vg
PGF CF
12/1/2018

13. Air motion (role of wind)
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14. Coriolis Effect - Page 166- 169
Longitude and latitude Lines
Our Lat/Lon
This effect is like a force is a result of the fact that we are on a rotating planet.
It is proportional to speed, and always acts to the right of the motion in the Northern Hemisphere (and to the left of the motion in the Southern Hemisphere).
CF = fv
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