Geo::WeatherNWS - A simple way to get current weather data from the NWS.
use Geo::WeatherNWS; my $Report=Geo::WeatherNWS::new(); # Optionally set the server/user/directory of the reports $Report->setservername("weather.noaa.gov"); $Report->setusername("anonymous"); $Report->setpassword('emailaddress@yourdomain.com'); $Report->setdirectory("/data/observations/metar/stations"); # Optionally set a template file for generating HTML $Report->settemplatefile(/"path/to/template/file.tmpl"); # Get the report $Report->getreport('kcvg'); # kcvg is the station code for # Cincinnati, OH $Report->getreporthttp('kcvg'); # same as before, but use the http # method to the script at # weather.noaa.gov # Check for errors if ($Report->{error}) { print "$Report->{errortext}\n"; } # If you have the report in a string, you can now just decode it my $Obs="2002/02/25 12:00 NSFA 251200Z 00000KT 50KM FEW024 SCT150 27/25 Q1010"; $Report->decodeobs($Obs);
New for version 1.03: the getreporthttp call now calls the script on the weather.noaa.gov site for those who cant FTP through firewalls. This module is an early release of what will hopefully be a robust way for Perl Programmers to get current weather data from the National Weather Service. Some new functions have been added since the 0.18 release. Instead of having to use the built-in server/user/password/directory that the module used to use, you can provide your own. This way if you have access to a mirror server of the data, you can specify the servername, account information and directory where the files exist. If you dont have access to a mirror, then you dont have to specify anything. The old server, etc., are still automagically selected. Also new in this release is that the getreport function now returns an error code and the FTP error message if anything goes wrong. Before this was added, if the server was busy or the stations text file was missing you couldn't tell what happened. Another new feature is the template system. You can specify a file with the settemplatefile function. This file is read in and all of the places in the file where the code sees %%name%% will be replaced with the proper values. An example template has been included. The template uses the same names as the hashref returned by the getreport function. And, same as previous releases, the getreport function retrieves the most current METAR formatted station report and decodes it into a hash that you can use. Some users had reported that they wanted to re-decode the raw observations later. If you store the "obs" value as a string, and you want to re-decode it later, you can now use the decodeobs function. I thought this would be a useful module, considering that a lot of sites today seem to get their weather data directly through other sites via http. When the site you are getting your weather data from changes format, then you end up having to re-code your parsing program. With the weather module, all you need is a four-letter station code to get the most recent weather observations. If you do not know what the station code is for your area, check the site at http://205.156.54.206/oso/siteloc.shtml to start your search. Since this module uses the NWS METAR Observations, you can get weather reports from anywhere in the world that has a four-letter station code. This module uses the POSIX and Net::FTP modules, so you'll have to make sure that everything is set up with them before you can use the module. To begin: use Geo::WeatherNWS; my $Report=Geo::WeatherNWS::new(); If you want to change the server and user information, do it now. This step is not required. If you dont call these functions, the module uses the defaults. $Report->setservername("weather.noaa.gov"); $Report->setusername("anonymous"); $Report->setpassword('emailaddress@yourdomain.com'); $Report->setdirectory("/data/observations/metar/stations"); If you want to specify a template file, use this: $Report->settemplatefile("/path/to/template/file.tmpl"); After setting the above, you can get the data. $Report->getreport('station'); Now you can check to see if there was an error, and what the text of the error message was. if ($Report->{error}) { print "$Report->{errortext}"; } If you have the report in a string, you can now just decode it my $Obs="2002/02/25 12:00 NSFA 251200Z 00000KT 50KM FEW024 SCT150 27/25 Q1010"; $Report->decodeobs($Obs); Assuming there was no error, you can now use the $Report hashref to display the information. Some of the returned info is about the report itself, such as: $Report->{day} # Report Date $Report->{time} # Report Time $Report->{station_type} # Station Type (auto or manual) $Report->{obs} # The Observation Text (encoded) $Report->{code} # The Station Code This is the template output: $Report->{templateout} These are the returned values specific to the conditions: $Report->{conditionstext} # Conditions text $Report->{conditions1} # First Part $Report->{conditions2} # Second Part These are the returned values specific to wind: $Report->{windspeedmph} # Wind Speed (in mph) $Report->{windspeedkts} # Wind Speed (in kts) $Report->{winddir} # Wind Direction (in degrees) $Report->{winddirtext} # Wind Direction (text version) $Report->{windgustmph} # Wind Gusts (mph) $Report->{windgustkts} # Wind Gusts (kts) These are the retunred values specific to temperature and humidity: $Report->{temperature_f} # Temperature (degrees f) $Report->{temperature_c} # Temperature (degrees c) $Report->{dewpoint_f} # Dewpoint (degrees f) $Report->{dewpoint_c} # Dewpoint (degrees c) $Report->{relative_humidity} # Relative Humidity (in percent) $Report->{windchill_f} # Wind Chill (degrees f) $Report->{windchill_c} # Wind Chill (degrees c) $Report->{heat_index_f} # Heat Index (degrees f) $Report->{heat_index_c} # Heat Index (degrees c) Note: Due to the formulas used to get the heat index and windchill, sometimes these values are a little strange. A check to see if the heat index is above the temperature before displaying it would be a good thing for you to do. You probably don't want to display the windchill unless its cold either. These are the return values for clouds and visibility: $Report->{cloudcover} # Cloudcover (text) $Report->{cloudlevel_arrayref} # Arrayref holding all cloud levels $Report->{visibility_mi} # Visibility (miles) $Report->{visibility_km} # Visibility (kilometers) These are the return values for air pressure: $Report->{pressure_inhg} # Air Pressure (in mercury) $Report->{pressure_mmhg} # Air Pressure (in mm mercury) $Report->{pressure_kgcm} # Air Pressure (kg per cm) $Report->{pressure_mb} # Air Pressure (mb) $Report->{pressure_lbin} # Air Pressure (psi) Other values MAY be returned, but only if there are remarks appended to the observations. This section of the code is more experimental, and these names could change in future releases. $Report->{remark_arrayref} # Arrayref holding all remarks $Report->{ptemerature} # Precise Tepmerature Reading $Report->{storm} # Thunderstorm stats $Report->{slp_inhg} # Air Pressure at Sea Level (in mercury) $Report->{slp_mmhg} # Air Pressure at Sea Level (mm mercury) $Report->{slp_kgcm} # Air Pressure at Sea Level (kg per cm) $Report->{slp_lbin} # Air Pressure at Sea Level (psi) $Report->{slp_mb} # Air Pressure at Sea Level (mb) Another note: Do not be surprised if sometimes the values come back empty. The weather stations are not required to place all of the information in the reports.
use Geo::WeatherNWS;
my $Report=Geo::WeatherNWS::new(); $Report->getreport('khao'); # For Hamilton, OH
print "Temperature is $Report->{temperature_f} degrees\n"; print "Air Pressure is $Report->{pressure_inhg} inches\n";
# If it isnt raining, etc - just print cloud cover
if ($Report->{conditionstext}) { print "Conditions: $Report->{conditionstext}\n"; } else { print "Conditions: $Report->{cloudcover}\n"; }
Marc Slagle - marc.slagle@fulkertconsulting.com
To install Geo::WeatherNWS, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Geo::WeatherNWS
CPAN shell
perl -MCPAN -e shell install Geo::WeatherNWS
For more information on module installation, please visit the detailed CPAN module installation guide.