When working a local position, you should post and update at ATIS for the airport. This is accomplished with the vATIS program.
Go to the Downloads page of the ZSE website and find your applicable facility file. These are grouped by the radar facility when applicable.
When you open vATIS, you will be able to import the facility file, and then open it. Once you import it, it will be automatically updated with any changes made by the Facilities department.
Pick a status from the dropdown at the bottom of the window that matches current conditions.
Click Connect to put your ATIS online. For airports other than SEA and PDX, you MUST click Record ATIS and then record yourself speaking the full ATIS.
See the documentation for more info on using vATIS
The ATIS is based directly off of the current METAR. Using the following as an example:
METAR KHIO 192253Z 12012KT 10SM FEW011 SCT019 BKN055 09/04 A2966 RMK AO2 SLP044 T00890044
Airport name: "Portland-Hillsboro" or "Hillsboro Tower"
ATIS information: Alpha
Observation time: 22:53 zulu
Wind: 120 @ 12
Visibility: 10
Sky condition: Few clouds at 1 thousand 1 hundred, 1 thousand 9 hundred Scattered, Ceiling 5 thousand, 5 hundred broken.
CLR (used in automated systems): Clear below one two thousand.
SKC (used in manual station): Sky Clear
FEW: "Few clouds at xxx"
SCT: "xxx Scattered"
BKN: First lowest BKN or OVC layer starts with "Ceiling xxx Broken" if not the lowest "xxx Broken"
OVC: First lowest BKN or OVC layer starts with "Ceiling xxx Overcast" if not the lowest "xxx overcast"
VV: Indefinite ceiling (hundreds of feet. VV002 "2 hundred"
Temperature: 9
Dew point: 4
Altimeter: 29.66
Remarks: If there was anything in the remarks relevant to significant weather like Thunderstorms, Lightning, Cumulonimbus clouds
NOTAMS: Any NOTAMS at the airport, like a closed runway or taxiway.
Now you must advertise which runways and approaches to use, Visual or instrument approaches. If you have a radar controller on above you ask them what approaches they want to use. Because the ceiling is at 5,500 we can probably advertise visual approaches.
METAR KHIO 192253Z 12012KT 10SM FEW011 SCT019 BKN055 09/04 A2966 RMK AO2 SLP044 T00890044
You would say the following when you record the ATIS:
"Portland-Hillsboro information Alpha, 2 2 5 3 Zulu. Wind 1 0 0 at 1 2. Visibility 1 0. Sky conditions, Few clouds at 1 thousand 1 hundred, 1 thousand 9 hundred Scattered, Ceiling 5 thousand, 5 hundred broken. Temperature 9, dewpoint 4, altimeter 2 9 6 6. VIS approach in use Landing and departing runway 13R. Advise on initial contact, you have information Alpha."