How to Read a METAR Report, Page 9 of 10

Read through this section now, but it's mostly useful as a reference. When you encounter something in a METAR report you don't understand, see if it's here. And when you encounter an abbreviation that doesn't seem to have any letters in common with the word it stands for, it's probably an abbreviation of the French.

Weather

Intensity: - = light, nothing = Moderate, + = heavy
Modifiers: SH = shower, TS = thunderstorm, FZ = freezing, MI = shallow, PR = partial, BC = patches, DR = low drifting, BL = blowing
Precipitation: RA = rain, SN = snow, DZ = drizzle, SG = snow grains, IP = ice pellets, IC = ice crystals, GR = hail, GS = small hail or snow pellets, UP = unknown precipitation type (automated report)
Obscuration: FG = fog, BR = mist (light fog), HZ = haze, FU = smoke, SA = sand, DU = dust, VA = volcanic ash, PY = spray.
Other: FC = funnel cloud or tornado, PO = dust devils, DS = dust storm, SS = sandstorm, SQ = squalls.

Sky Cover

SKC (manual) or CLR (automated) : no clouds
FEW : Up to 1/4 of the sky obscured by clouds.
SCT : Up to 1/2 of the sky obscured by clouds.
BKN : More than 1/2 of the sky obscured by clouds.
OVC : All of the sky obscured by clouds.

Other Stuff

Sometimes you'll see Runway Visual Range (visibility along a particular runway) reported after the regular visibility group. It will be a long string of characters beginning with an R. I don't have time to decode it here. It's of primary importance to aviators, but not to meteorologists.

The rest of this stuff is in the remarks, and is only reported if it's appropriate. Peak wind: PK WND, followed by the wind direction and speed, a slash, and the time of occurrence. Wind shift: WSHFT, followed by the time of occurrence. Useful for detecting fronts and such. Lightning: LTG, preceded by frequency (OCC, FRQ, etc), followed by location (NE, etc.). Virga: VIRGA (precipitation visible but not reaching the ground). Sea level pressure: SLP, followed by encoded pressure group: tenths of millibars, only last three digits reported.

Questions or Comments

Technical: E-mail John Fulton < jdfult@nimbus.met.tamu.edu >
Scientific: E-mail Dr. John Nielsen-Gammon. < nielsen@ariel.met.tamu.edu >