Decoding Guide

Weather Depiction Chart


This product depicts surface observation reports of Low Instrument Flight Rules (LIFR), Instrument Flight Rules (IFR), Marginal Visual Flight Rules (MVFR), and Visual Flight Rules (VFR) conditions.


Every 30 minutes

Data Sources:

Surface observations


Magenta dots indicate LIFR condtions.
Red dots indicate IFR conditions
Blue dots indicate MVFR conditions
Green dots indicate VFR conditions


LIFR Ceilings below 500 ft and/or visibility less than 1 mile
IFR Ceilings less than 1000 ft and/or visibility less than 3 miles
MVFR Ceilings between 1,000 and 3,000 ft and/or visibility between 3 and 5 miles
VFR Ceilings greater than 3,000 ft and visibility greater than 5 miles