GENERAL:

Time-height graphics give a vertical profile representation of the forecasted conditions at a specific location over time. The current conditions are represented on the far right side. As you move to the left you are moving forward in forecast time. The level of the atmosphere is labeled on the left side in mb and the time is labeled on the bottom. Regions of solid yellow/mustard color are below ground. Along with time-heights each location has a complementary suite of products that include a forecasted sounding and meteogram product.

RED LINES:

Solid red lines represent the air temperature in degrees Celsius at the station selected. These lines are called isotherms that are defined as lines of equal temperature.

GREEN LINES:

Solid green lines represent the relative humidity (RH) in percent at the station selected. These lines are defined as areas of equal RH. RH over 70% are shaded light green with regions over 80% shaded a darker green.

WIND BARBS

Evenly spaced on the graph are wind barbs that indicate the strength and direction of the wind. They are stacked vertically to represent the wind at different levels in the atmosphere at the station location. The height level is determined by pressure levels labeled on the far left of the graph.

1 kt ~ 1.15 mph ~ 1.85 km/hr

WHY IS THIS IMPORTANT?

Time-heights give forecasters a view of the vertical structure of the atmosphere over time. Dry and moist regions of the vertical atmosphere can easily be determined along with the stability of the air. One can ascertain how temperatures, freezing levels and moisture contents are predicted to change over the next 72-hours for a specific location. For a more detailed explanation please click here.