Weather Reporting Changes to Come

METAR

On November 15th, 1998, the abbreviation for ice pellets (PE) will change to (PL).

When prevailing visibility falls below 4 SM, the surface observation will always be in the body of the METAR/SPECI & tower visibility will be in the RMK section. Why? When visibility is reduced at an airport, two observations are made: surface & tower. If different, the most restrictive is reported in the body of the METAR & the greater number is placed in the RMK section.

Now introduce the new generation of "super towers" over 300 feet tall. If you have a ceiling of 300 feet, tower visibility could be 1/4 SM & surface visibility 1 SM. Under the old rule, 1/4 SM would be in the main body and 1 SM would be in the RMK. No bueno!

Tower visibility will no longer be recorded in the body of the report, regardless of any difference between the surface prevailing visibility and tower visibility values.

Controllers will still maintain a tower visibility certification (LAWRS) to observe visibility changes and to augment ASOS.