Numerical weather predictions Flashcards
What are the 2 configurations of the Global environmental multiscale model?
Regional
global
What are the differences between the 2 configurations?
Forecast duration:48 hrs regional, 120 hrs global
Resolution: Regional uses a smaller resolution
what are the different charts displayed in the 4 panel global and regional models?
- 500 hpa vorticity
- 850hpa (0 hour only)
- 700 hpa (humidity)
- MSL (thickness)
- Quantative Precipitation forecast (from +12H)
How many times daily are they prepared and based on which data?
twice daily, based on the 0000z and 1200z data
What does the 850hpa chart depict?
Isotherms at 5 degree intervals, and a phase change zone between -2.5 and 2.5 degrees. temperature maxima and minima are denoted by + and -
What does the 500hpa chart depict?
isopleths of absolute vorticity, vorticity maxima and minima are denoted by + and -
what does the 700hpa (humidity) chart depict?
- isopleths of average relative humidity
- areas with relative humidity of 70% or more are lightly stipled and over 90% are heavily stipled
what does the MSL (thickness) chart depict?
-1000-500 hpa thickness isopleths
what does the QPF chart depict?
- isohyets represent 1,5,10,25,50,100 mm accumulations
- they are the accumulations forecast during the preceeding 12 hours
List the 2 types of regional aviation models
- Icing/Turbulence
- clouds
What 4 charts are shown on the icing/turbulence models?
- Icing and freezing level
- Momentum flux
- High level turbulence and trop height
- Mid level turbulence
What is shown on the cloud charts
ceiling
When are the regional aviation model icing/turbulence charts issued?
based on 0000z and 1200z data and valid for Hr+6,+12,+18,+24
What does the icing and freezing level chart depict?
Freezing level and supercooled water
What does the momentum flux chart depict?
isopleths of surface stress, with a correlation of:
.75 = moderate turbulence
1.5 = severe turbulence
3.0 = extreme turbulence
What does the high level turbulence and trop chart depict?
- Tropopause heights
- isopleths of maximum deformation vertical shear index from 400hpa to 200hpa
What does the mid level turbulence depict?
-Isopleths of maximum deformation vertical shear index from 700hpa to 400hpa
What does the ceiling chart depict?
Low and mid level ceilings up to 24000ft.
What are the 5 types of FX messages?
- Main weather discusion
- Extended range forecast discussion
- Operational Run status
- Trenton military
- American FX
how often is the main weather discussion issued and how long does it cover?
twice daily, at 0930z and 2100z
-48 hrs
How are the forecast discussions different from the models?
They explain a human point of view of a weather forecast compared to a computer
How often is the extended forecast discussion issued and how long does it cover?
once daily at 0730
-from 48hrs to 120hrs
how often is the operational run status issued?
twice daily
how often is the trenton military discussion released?
once daily and updated as required
How often are the american FX issued?
twice daily and updated as required
