[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[IDD #LSK-251795]: Re: IDD and cloud cover in METARs

This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.

  • Subject: [IDD #LSK-251795]: Re: IDD and cloud cover in METARs
  • Date: Fri, 20 Nov 2015 13:14:20 -0700
> Jeff, thanks for the information. How is the measurement made?
> 

Well, back in the old days ;) it was done by the forecaster...now many have 
automated that process. That will be defined in the report:

The abbreviation “AUTO” is included in any METAR/SPECI which includes 
observations recorded without human input. Where no cloud is detected in such a 
report, the letters “NCD” will be included and in most cases, when a cloud base 
recorder does not detect any cloud and the recorded visibility is 1000 metres 
or less, the phrase “CLD:SKY MAY BE OBSC” will be included as a RMK.(remark) 

So, automated weather stations will use either LIDAR or a ceilometer currently 
and earlier (years) attempt at automation used an optical drum recorder...

Hope this helps, 

Jeff
Jeff Weber
Unidata User Support
http://www.unidata.ucar.edu

Ticket Details
===================
Ticket ID: LSK-251795
Department: Support IDD
Priority: Normal
Status: Open