Why are some station plots red or blue?
A red station plot indicates instrument flight rules (IFR), which means the ceilings are below 1000 feet and/or the visibility is below 3 miles. A blue station plot indicates marginal visual flight rules (MVFR), meaning the ceiling is below 3000 feet and/or the visibility is below 5 miles. These colors are good for helping you visualize areas of low ceilings and visibility at a glance. redblueplot What do the square station plots represent? The square symbol is reserved for automated stations. An automated report is signalled by either “AUTO”, “ASOS”, or other similar abbreviations in the report, or by the indicator for automated observations in a SYNOP report. squareplot CONTOURING Digital Atmosphere will let me perform one Barnes analysis, but if I try to perform a second Barnes analysis I receive a Range Check error. A couple of bugs in the functions used by the Cressman and Barnes analysis are known to exist. barneserror Upper level height contours don’t work. The computer freezes
