4/20/23 

AIM 

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