500 hpa and prog charts Flashcards
How long after observation time are the 500 vorticity and 500 thickness charts transmitted?
vorticity - 2 hrs
Thickness - 3.5 hrs
what are the letters or symbols used to indicate a vorticity maxima and a minima?
Maxima - C or +
Minima - A or -
Define Isopleth
Line of equal or constant value of a given quantity
The smaller the quadrilateral, the ______ the advection
greater
when isopleths are parallel to the contour lines, what is the advection value?
0
Define positive vorticity advection
Advection of higher values of vorticity, which is often associated with upward motion of the air.
What does negative vorticty advection represent?
Lower levels of vorticity moving towards higher levels of vorticity
NVA is associated with _______ and PVA is associated with _________
NVA - Convergence
PVA - Divergence
PVA is indicitive of:
Falling pressure, rising motion, and instability
The thickness pattern on the 500hpa chart reflects the :
Mean temperature of the layer between 500hpa and 1000 hpa and is proportional to the mean temperature of the air below 18000ft
Warm thickness advection supports:
Cyclogenesis
Fronts are usually located on the _____ of the thickness field.
warm.
the area between the 534 and 540 dashed lines is stippled to indicate ______ and is colored ______
change of phase state
yellow
The low to mid sfc prog chart (sfc to 400mb) contains:
- Pressure centers, surface fronts
- Surface positions of tropical storms
- significant clouds
- turbulence, freezing lvl, and icing
the comox sfc prog chart is issued for the period of __________
12, 24 and 36 hr