A Raw METAR Report

What do these things look like in the raw? And why should you care?

Here's the answer to the first question:

METAR> clt 12z

KCLT 041150Z 33009KT 4SM TS +SHRASHRA BR FEW005 SCT010CB OVC045 19/19 A2999 RMK

 OCNL LTGICCG TS N MOV NE SLP152 60072 70072 8/9// T01850185 10220 20185 53017

 K=

KCLT 041150Z COR 33009KT 4SM -TSRA BR FEW005 SCT010CB OVC045 19/19 A2999 RMK

 OCNL LTGICCG TS N MOV NE SLP152 60072 70072 8/9// T01850185 10220 20185 53017=

KCLT 041216Z 03005KT 5SM -SHRA FEW005 OVC040 18/18 A2999 TSE15 MOV E=

KCLT 041216Z COR 03005KT 5SM -SHRA FEW005 OVC040 18/18 A2999 RMK TSE15 MOV E=

There are actually four reports here. Each starts with the four-letter station identifier (CLT preceded by a K) and the date and time. You'll note that the observations are in pairs, with identical times. Furthermore, the second observation of each pair includes the letters "COR". What gives? Those are corrected observations. There was some sort of mistake in the first, and so a corrected one was sent out. Sometimes the change is trivial, such as omitting the remarks separator (RMK) at 1216 UTC. Sometimes the change is significant, like the weather at 1150 UTC. The first report has both heavy and moderate rain showers, but the correction changes that to a light shower with thunder. This information was unavailable in the fully decoded observation, and would have been difficult to figure out in the table-decoded observations. So if a particular observation is really important for some reason, look at it in its raw form.

Here's a quick rundown of the important parts of the code. First the station, then the date and time (Z = GMT), then the wind direction (first three digits) and speed (last two digits) and the abbreviation KT for knots. Then the visibility, in SM (statute miles), the present weather (if any), and the sky cover. The two numbers separated by a slash are the temperature and dew point, in Celsius. Then comes the altimeter setting, in hundredths of an inch of mercury, preceded by an A. Finally comes the remarks, which we've already talked about somewhat. ***

Now see how you do at reading a raw metar observation. The one below was taken from the landfall of Hurricane Bonnie in August 1998.

KILM 261753Z 05042G56KT 1 1/2SM RA BR SCT010 OVC015 26/24 A2912 RMK AO2 PK WND 07056/1747 PRESFR SLP862 P0017 60273 T02610244 10267 20244 58103=

1. What is the time of the observation?

2. What is the current wind speed and direction?

3. What is the current temperature?

4. How much rain fell during the previous six hours?