AWOS, or the Automated Weather Observation System is used by pilots to tell them them imporant variables about the weather such as: visibility, ceiling (cloud base), wind speed and direction, altimeter setting (i.e. atmospheric pressure), temperature, and humidity, and precipitation.

AWOS is a class of automated weather observation systems that can publish their data over the FAA's National Airspace Data Interchange Network (NADIN). From there the data is available to both aviation and weather forecasting/observing users. It is one of the best sources of real-time weather data on Campus.

A major supplier of AWOS systems is Allweather http://www.allweatherinc.com/aviation/awos_dom.html located in Natomas. There are ex-Davisite engineers employed by Allweather and at least one Davis company supplies components for their systems.

The Davis AWOS, based at the University Airport is operated by the Transportation and Parking Services, and can be accessed via phone (530)754-6839, http://awos.ucdavis.edu/, or radio 119.025 MHz AM (part of the VHF Airband). It is an Allweather (formerly Qualimetrics) Model 900 AWOS in the AWOS III configuration. This means the following sensors are present:

  • barometric pressure
  • temperature and relative humidity
  • wind speed and direction
  • visibility
  • cloud height
  • precipitation accumulation (rain gauge)

METAR and Technical Information

METAR is a weather description format used over radio and internet by http or ftp. A good http client and parser for METAR is the metar project: http://www.leune.org/metar/. Although there are various nifty desktop applications that can pull this data and the National Weather Service does carry this feed, if you use it regularly, you will notice that there are odd gaps in the University Airport feed during which it doesn't update. It is not in the listings, so you'll have to find a way to insert the code KEDU (formerly 0O5) into the software. To read them manually (or just understand how they work), check out the Weather Underground METAR FAQ.

If all else fails, KSMF is a very reliable feed and has a good METAR feed (forecasts and alerts). It is based at Sacramento International Airport, close enough for most weather information to be accurate for Davis as well.

Other local stations are:

  • DWA (formerly 2Q3) - Yolo County, 125.775 MHz
  • FR10776 - Medlock Field, Davis
  • FR10782 - Maine Prairie, Dixon
  • FR10752 - CHP Academy (off just east of West Sacramento)

There is a feed for Winters as well, but I don't have it in my notes. Anybody know it?

The AWOS observation broadcast on 119.025 is transmitted with AM modulation. Because of a peculiarity of the AM process, an FM receiver nearby can pick up the signal but with a very low volume.

What is a feed? RSS? Maybe you get this stuff over the internet, but if it is for small planes, radio, not internet is probably it's primary media, so we should explain about that if we are going to have all the other places. I thought it was fine just talking about the University Airport. If we are going to talk about the other airport weather stations we should explain a lot more about the FAA weather system, which I'm not sure we want to.-NickSchmalenberger

  • The specific reason I listed them here is because they are a pain in the ass to find online. There is no easy "give your location and here are the closest stations, and here are their update schedules and information carried". It's compiled from a handful of text files located in various sites around the internet. Weather information is very geeky and not a simple topic... and this is the relevant information for Davis. I really really hate the idea that the Wiki can only list the "popular trendy easy to use" resources like RSS feeds. METAR may not have a OSX screensaver for it, but it is valid information useful to Davis residents who want it. When I see "Here are some METAR feeds", I know exactly what it means. If you say "Here are some RSS feeds", you're going to confuse a good chunk of visitors. Don't dumb down the Wiki. — JabberWokky
  • I think the extra info is good... also, if this page was really to only have information for the University Airport it'd seem better suited to just be a section on that page, rather than being a whole separate page. —Jevan

Is it just me, or does KSMF have an ASOS instead of an AWOS? —BrentLaabs

  • Have you guys seen this faa page before? For one thing it shows that SMF has an ASOS. —Jevan
  • No idea, but it would be nice to list the equpment at each location. I think last three I listed are operated by Forestry Service rather than NWS... it would be nifty to list the governing body for each as well. It would also be good to list frequency info for the direct feed; I haven't played with them since I was an active HAM operator years and years ago. It took me awhile to compile this list; with the IDs, it should be easier to locate additional information (maybe even go out and get some pictures of the units!). — JabberWokky
    • The NWS provides some basic info on METAR sites, but I don't think that's what you're looking for. I'm coming at it from the meteorological viewpoint. My department's weather station appears to be running in real time, once again. CIMIS also operates it's own weather station, just north of my department's, but you can only get data once a day. And they make you register for a frelling account. Of course, these aren't AWOS/ASOS at all.—BrentLaabs
      • No, no... I was talking about information about the actual equipment - serial numbers, history of the installation, pictures of the setup, the name of the engineer in charge of it, etc. It would interest... uhh... me. I think. Still, no stranger than listing all the manhole covers or payphones. I've poked at a couple stations and always found them nifty. — JabberWokky
        • I think this is a great idea. I also agree that we should list the frequencies for the others because that is their primary media, being for pilots after all. I have already done so for the ones I could find. What is the application layer protocol for these "feeds"? We need to explain that if people are ever going to know how to receive them. Also, since I assume they are text only, I don't see why a "desktop application" is necessary. Maybe you could mention one GUI and one console application for these "feeds" when you say the protocol. -NickSchmalenberger
        • I also agree with you, JabberWokky, about RSS. If it is so simple, why do they bother with "Really"? Superlatives only complicate. Anyway, RSS was just the only thing I could think of that is called a "feed", and all I wanted to know was the application protocol. Is there an RFC? Thanks. -NickSchmalenberger
          • METAR is a well defined protocol, if that's what you mean. It predates XML, so it's a simple block of text. A Google search pulls up a few good protocol descriptions and most text processing languages (perl, python, php, etc) have standardized libraries to parse it. METAR is a syndication protocol - the actual data can be read directly off the units (pilots do this when landing) using a VHF decoder, as they broadcast their data. Different units have slightly different protocols — there have been three or four different standards over the years. Do a couple searches or ask a pilot or meterologist... the information is very open and available. Nifty, too, if you're into stuff like this. — JabberWokky
          • I added some description of the protocol and a link to a client. In the case of radio, what is the modulation and encoding? -NickSchmalenberger P.S. If I used the word "feed" in this sense I would feel like livestock.

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