[Editor's Note: Instructions for decoding the 5 digit code from RECCO is reprinted below. This report is time stamped as

1. Time = 2308 GMT = 19:08 EDT = 7:08 PM EDT

2 The center of the Hurricane is Lat. 27.1 North and Long. 84.4 West

3. The altitude of the monitoring aircraft is 5190 meters = 16,660 feet

4. The winds at this altitude (16, 660 feet) are 29 knots or 33 mph and coming from the south (180 degrees) surface winds will be much stronger, but the loss of velocity in upper winds will be mirrored by a loss of velocity in surface winds. This hurricane appears to be weakening considerably based on this data. .Ken]

http://educate-yourself.org/cn/RECCOritadata2308GMT22sep05.shtml
September 22, 2005, 23:08 GMT

http://www.nhc.noaa.gov/text/MIAREPNT0.shtml?

RECCO Observations (non-tropical cyclone)

000
URNT10 KWBC 222308
97779 23084 50274 84419 51900 18029 53557 /4588
RMK NOAA2 WX18A RITA OB 23 KWBC
LAST REPORT. OBS 01 THRU 23 TO KNHC VIA KWBC.

Instructions to decode the RECCO 5 digit code

1. The Basics of RECCO Code
RECCO observations are a series of 5-digit numbers. What you want to be able to do is recognize when and where the observation was taken, and some key meteorological data. (Die-hard meteorology buffs who want a full decoding of the RECCO code, continue to the next section.)

Example:
URNT11 KNHC 161227
AF967 0212A LILI OB 08 KNHC
97779 12314 40169 82508 04000 22020 25218 /0007 42115;

The first two lines are the heading of the message.

The first group is almost always "97779".

Time. The first four numbers in the second group is the time of the observation, in Greenwich Mean Time (subtract 4 hours to get Eastern Daylight Time, 5 hours to get Central Daylight Time, or subtract 6 hours to get Central Standard Time). In the example, "1231" is 1231 GMT, or 7:31 a.m. CDT.

Location. Find the latitude in the last three digits of the third group, and the longitude in the first three digits of the second group. The latitude and longitude are reported in degrees and tenths. If the longitude is 100.0 degrees or above, the first "1" is dropped in the code, for example, 104.3W is coded "043"; you need to look elsewhere in the code if you aren't sure if that was 4.3W or 104.3W. In the above example, the aircraft was at 16.9N 82.5W.

Altitude. The first three digits of the fifth group tells you approximately how high the aircraft is flying. It is coded in "decameters", which means you need to multiply this number by 10 to convert to meters, then multiply by 3.281 if you want to convert to feet. In the above example, the altitude is coded "040" = 40 dm = 400 m = 1312 ft. This tells you the aircraft is on a low-level mission.

Winds. The sixth group is the wind measured at the altitude of the airplane. The first two digits are the wind direction, to the nearest ten degrees. Wind direction is reported similar to compass headings, where 360 or 0 degrees is north. In the code, 09=east, 18=south, and 27=west. The next three digits is the wind speed in knots. Multiply by 1.152 to convert to miles per hour. In the above example, "22020" is a wind of 220 degrees (blowing out of the southwest) at 020 knots (23 mph).

Pressure. The eighth group, always begins with a "/". The second digit tells you at what level the aircraft is flying. A "0", as above, shows the aircraft is flying below 1500 feet and is estimating sea-level pressure. The next three digits is the pressure or height data. Only if the second digit is a "0" will this be sea-level pressure (in millibars). In the above example, the sea-level pressure is 1007 millibars. This is a complicated group, and for aircraft flying above 1500 feet, see the full decode below.

2. Here is the breakdown of the mandatory section of the code:

 

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Page last modified: Thursday, 22-Sep-2005 17:16:00 MDT