Wx

Ceilings

(1800wxbrief)

•VFR >5 SM, >3000' ceilings

•MVFR 3-5 SM, 1-3000' ceilings

•IFR 1 to <3 SM, 500 to <1000' ceilings

•LIFR <1 SM, <500 ceilings

VFR

Visibility greater than 5 miles and ceiling greater than 3000ft AGL

MVFR

Visibility 3 to 5 miles and/or ceiling 1000ft AGL to 3000ft AGL

IFR

Visibility 1 mile to less than 3 miles and/or ceiling 500ft AGL to below 1000ft AGL

LIFR

Visibility less than 1 mile and/or ceiling below 500ft AGL

N/A

Flight Category cannot be determined from data or data is too old or data is not valid for the forecast period.

see also

• GFA (Ceiling & Visibility) url
• AIM 7-1-7 b. url
  • The cause of LIFR, IFR, or MVFR is indicated by either ceiling or visibility restrictions or both. The contraction “CIG” and/or weather and obstruction to vision symbols are used. If winds or gusts of 25 knots or greater are forecast for the outlook period, the word “WIND” is also included for all categories including VFR.

1. LIFR CIG-low IFR due to low ceiling.
2. IFR FG-IFR due to visibility restricted by fog.
3. MVFR CIG HZ FU-marginal VFR due to both ceiling and visibility restricted by haze and smoke.
4. IFR CIG RA WIND-IFR due to both low ceiling and visibility restricted by rain; wind expected to be 25 knots or greater.

• NWS Jetstream–Online School for Weather url