MesoWest Graphical Links with Prior Observations

MesoWest has been designed for use by National Weather Service meteorologists and other professionals for protection of life and property. Comments and suggestions for improvement are encouraged and can be sent to

The Graphical Links with Prior Observations allows users to view current weather data from a selected station and compare it to data from previous dates. Data will be displayed in a graphical format or in a tabular format, and users can select options to choose the days to compare the data too. Comparisons can be made to data from yesterday, from the same day in previous years, or up to + or - 2 days of the selected day. Additionally, data can be compared in user-specified time intervals, up to a range of 48 hours before and after for a total time interval of up to 96 hours.

The page reloads every 5 minutes in order to display the most current conditions available.


The user can select the following types of data to compare:

How to access:
  1. Select a station by either using the search box on the top left corner of the home page or by selecting a state from the map on the home page, and then selecting one of the stations.
  2. If you clicked on a station from the map, click on "Additional Tabular and Graphical Displays". This will take you to the station interface (for more information on the station interface, click here.
  3. Under the "With Prior Obs" header on the table, select the data that you would like to view.
  4. A graph of the data will appear; use the legend at the top to differentiate the line colors.
  5. At the bottom is a variety of boxes that can help decide what days the data will be compared to. The first box ("Compare To") will compare the current data to other data from either the previous day or the same day in prior years (and the green line will change to what you select). "Calendar Period" will allow users to compare the selected day's data to the data from either 1 or 2 days before and after the selected date. "Back" and "Forward" will let users change the time interval on the graphs, up to 48 hours before or after the selected time.