National Weather Service United States Department of Commerce

The Pacific Storm Expected to Produce Multiple Impacts as it Moves Eastward

Heavy snow will extend from the mountains of California and the Intermountain West into the Northern Plains. Gusty to strong winds may produce critical fire weather risks over portions of the Central and Southern High Plains. Multi-hazard impacts will stretch from the Lower Mississippi Valley to the Great Lakes by Friday into the weekend. Read More >

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Meteorological data from over 2800 automated environmental monitoring
stations in the western United States are collected, processed,
archived, integrated, and disseminated as part of the MesoWest program.
MesoWest depends upon voluntary access to provisional observations from
environmental monitoring stations installed and maintained by federal,
state, and local agencies and commercial firms. In many cases,
collection and transmission of these observations are facilitated by NWS
forecast offices, government laboratories, and universities. MesoWest
augments the Automated Surface Observing System (ASOS) network
maintained by the NWS, Federal Aviation Administration, and Department
of Defense. MesoWest increases the coverage of observations in remote
locations and helps capture many of the local and mesoscale weather
phenomena that impact the public.

The primary goal of MesoWest is to improve timely access to automated
observations for NWS forecasters at offices throughout the western
United States. In addition, integration of the observations into
analyses of surface conditions at high spatial and temporal resolution
provides additional tools for nowcasts and forecast verification.
MesoWest observations are being used for many other applications,
including input to operational and research models and research and
education on weather processes in the western United States.

Question: Please provide a link with a description of your terminology
For example what does "T" mean under Precip 1 hour (the 3 day history)
or the "BKN075" under clouds?

Answer; Explanation of Wx and Clouds columns:
This legend explains how to decode the weather and clouds on
observation listings pages:

MesoWest Data Variables:

Reading WNUM Values from Mesonet API:

ASOS Generated METAR/TAF List Of Abbreviations And Acronyms:

Federal Meteorological Handbook No. 1 - Surface Weather Observations and Reports:

Question: A particular station is not reporting Wind (Temp, Precip, Pressure...)

Answer: Most of the weather stations in Mesowest are not maintained nor controlled
by the National Weather Services. The data is just made available as a service to our
customers. Problems with a particular station not reporting correctly is outside of
our control.

Question: I would like to put up an automated weather station and supply data
for my area. What type of stations are most sites using? How do I register a
station with MesoWest once I have it operating and on the internet?

Answer: MesoWest obtains nearly all of our citizen weather observations through
the Citizen Weather Observer Program (CWOP) (
We believe their website has information on how to get a system up and
running as well as communicating with the world. These CWOP observations
then get ingested into a system known as Meteorological Assimilation Data Ingest System, MADIS
( which in turn sends the data
to us here at Mesowest. As such Mesowest does not directly interact with
individual citizen weather stations.
As far as the type of weather stations: There are a range of possibilities
for high quality weather stations. There are some links and ideas if you dig around
on the CWOP page. A few companies you might look at are Davis Instruments, Vaisala,
Cambell Scientific (weatherhawk), lacrosse, and we are sure there are many more.
Set Up 5-minute weather data CWOP, an Example
Question: Where can I download historic RAWS data for plotting in a spreadsheet?
I cannot seem to locate any links for downloading data.
I am interested in 2008-2010 temperature and rainfall data
from station MDDC1-Mad River in NW California.

Answer: Mesowest provides a video describing how to download data:
As described in the video, if you search for the station you are
seeking for by typing in the station's id, you are directed to this page:
On the lower left hand side of the page, you will see a link called
"download data."
You can then fill in the desired options. If you do not have a
mesowest account, you will only be allowed to download a day's worth
of data. However, if you register for a free mesowest account, you can
download up to 31 days of data at a time, as Mesowest is provisional.
If you would like more information and data, you can go to the
official archive site Western Regional Climate Center:


Question: Is there any method available to archive all the met sites you have included on the map?  Preferably automatic – something I could initiate on a weekly basis for example.  This is a good website to archive all met data in a select region.  Specifically, I am interested in wind data for Vermont.

Answer: Register with the data maintainers located at University of Utah (Salt lake City):

---and get a token from them (use that token, to get the required/interested data)..

---replace that TOKEN with the STRING---that they'd provide you (in the web link below):

Web link/page above, may need be adjusted (depending on how the API works at the time).

Question: We here at LA County Fire are looking to publish RAWS data for
Stations within Los Angeles County on our own website and possibly a smartphone app.
To that end I am looking for the raw data. Can this data be found anywhere
online, text file or csv?
*Real-time data is contained in the mesowest.dat.gz CSV file, found here: This file is generated every 15 minutes and
contains the latest 15 minutes of observations received. Archive data can
be found via the Western Regional Climate Center page:

However, if this data is intended to be published, please be sure to review
the Usage Restrictions for MesoWest data which can be found here:
Question: A Typical Concern,
The Mesowest sensor at LUFI1 has been flaky over the past few weeks, as far as
reporting wind speed and direction. Looks like it has gone south for the season now.

Answer: MesoWest does not own or operate the stations in our database.
You will need to contact the station owners to learn more about the problems
with the station. For a station like, LUFI1 : ,
the owners are the Bureau of Land Management (
and the Boise Interagency Fire Center (
Station Owner [responsible party]
---> Left Menu (above face book link) (LeftMenu---topLeft)
---whose network it belongs to: (DATA COURTESY OF:)
contains the station owner information that need be contacted.

MesoWest Variables are defined here: or: here.
16G23 indicates:
16=sustained wind speed, G23=wind gust speed
Question: I would like to know: on your wind direction data, the wind is
blowing "from" direction, or blowing "to" direction?
Answer: The standard for automated data is the wind blowing "from" direction.
Question: How do you determine if a station is "active" or "inactive"?

Answer: Provided by the MesoWest data maintainers:
Our procedure for setting the active/inactive flag, which applies to all stations, is that any station that has reported an observation in the past 30 days is "active". After 30 days of no observations, a station is set to "inactive". Also, new stations are :"active" for 30 days after they have been inserted in the db, whether they have reported data or not. New RAWS are flagged "active" within 15 minutes of being inserted in the db; the status for other stations is checked daily at 2:30 am. It is not possible to change the flag in the db outside this procedure. (If data providers, users, etc could set the flag using different criteria, then the flag would become meaningless.) To NWS Forecast Offices: Keeping your own status flag for stations of interest would be an alternative.


Question: Hello, A question has been in the back of my mind for quite a while concerning your point forecasts. In the Current Conditions section, there is a statement about "Observation Quality". Most of the time when I am looking at the Bozeman forecast, or almost any location for that matter, I see that the Quality is listed as "Caution". In fact, at this point in time, the Billings forecast is the only one I can find without this disclaimer. Even your Gt. Falls forecast has a cautionary note to it! Can you please explain what constitutes a "Caution" level of quality, or where I can find such information? I`ve tried various searches of the NOAA website for such information but only come up with links to general "quality" hits. Thanks for taking the time to respond!

Answer: When the observation is `old`, we have the word `Caution` so that the user is alerted to the fact that the data is not `current`.


I am interested in obtaining archived data for a weather station
(DESATOYA MOUNTAIN, NV (GRVN2). How do I access such information?

Answer: You should be able to access archived data for GRVN2
through the MesoWest Download Interface available here...

To download up to a year of data in one transaction, you can create
a free My MesoWest account. That can be done by clicking the
'My MesoWest' link listed on the page and then clicking the option
to create a new user account. Unfortunately, we do not currently have
the capabilities for you to download more than more year of data into
a single file. We hope to incorporate that feature in the future.
See the Download Data Help Page for more information:
In order to download up to a year of data in one transaction, a
My MesoWest account is required. iAgain, additional details regarding the
Data Download Interface can be found at the above download link.

Please be aware that MesoWest data are collected in real-time and are considered provisional:

The official archive for RAWS stations, such as GRVN2, is
The Western Region Climate Center:

Forums & Frequently Asked Questions for CWOP: _____________________________________________________________________________
List of stations near MesoWest KSFO that have reported data at least once in the last 90 days.

Anyone with questions about RAWS stations should contact the RAWS Help Desk:, since they often then forward the information to
whomever the request is relevant to.
MesoWest Data Providers:
MesoWest Status Page
NWS Telecommunication Operations Center:

I hope that this is of some help, regarding Mesowest.