4. Interpolation of time periods between AIRMETs over the contiguous U.S. valid times: Users must keep
in mind when using the AIRMET over the contiguous U.S. that if a 00-hour forecast shows no significant
weather and a 03-hour forecast shows hazardous weather, they must assume a change is occurring during the
period between the two forecasts. It should be taken into consideration that the hazardous weather starts
immediately after the 00-hour forecast unless there is a defined initiation or ending time for the hazardous
weather. The same would apply after the 03-hour forecast. The user should assume the hazardous weather
condition is occurring between the snap shots unless informed otherwise. For example, if a 00-hour forecast
shows no hazard, a 03-hour forecast shows the presence of hazardous weather, and a 06-hour forecast shows
no hazard, the user should assume the hazard exists from the 0001 hour to the 0559 hour time period.

Meteorology

7-1-17