Surface Weather Map Overlays Help Page

MesoWest has been designed for use by National Weather Service meteorologists and other professionals for protection of life and property. Comments/suggestions for improvement may be sent to atmos-mesowest@lists.utah.edu.

As mentioned in the Surface Weather Maps Help Page, the Surface Weather Maps also allow the user to display image layers onto the map in addition to observations.

The majority of the layers are provided by the NOAA Real-Time Mesoscale Analysis (RTMA). Click here for more information on test parallel RTMA analyses.

Recall that to access these layers you have to click "Layer Options" on the left-panel of the map interface. Once clicked a menu will appear displaying the layer options.

Layers: The following layers are available for display...
Base Layers: you can choose one of these as a base layer for your map...
Google Terrain: display the Google Terrain map.
Google Hybrid: display the Google Terrain map with a road map overlay.
Google Map: display the Google road map.
Roads on Top: display the roads on top of all overlaid data.
Elevation (USGS Gray): an elevation map provided by the United States Geological Survey.
Weather Overlays: you can choose one or multiple layers of the following...
RTMA Precipitation (in): RTMA Estimated Precipitation Grid in inches.
RTMA Precipitation (mm): RTMA Estimated Precipitation Grid in millimeters.
RTMA Temperature (F): RTMA Surface Temperature Grid in degrees Fahrenheit.
RTMA Temperature (C): RTMA Surface Temperature Grid in degrees Celsius.
RTMA Dew Point (F): RTMA Surface Dew Point Grid in degrees Fahrenheit.
RTMA Dew Point (C): RTMA Surface Dew Point Grid in degrees Celsius.
RTMA Wind Speed (>2.5 MPH): RTMA Surface Wind Grid with speeds greater than 2.5 mph.
RTMA Wind Speed (>2.5 MPS): RTMA Surface Wind Grid with speeds greater than 2.5 meters per second.
NWS Watch/Warn: National Weather Service Watch and Warning products.
US NEXRAD Radar: NEXRAD Composite Radar graphic from the Iowa Environmental Mesonet.
Boundary Overlays: you can chose one or multiple layers of the following...
County Warning Areas: outline the National Weather Service office boundaries.
NWS Fire Zones: outline the National Weather Service fire zones.
GACC Boundaries: outline the NICC Geographic Coordinating Areas.
Roads on Top: check to bring roadways to the top layer.

Opacity Settings: These allow the user to control the transparency of the layer. Options from 0.25 to 1 are available, with 1 being completely opaque. Setting the opacity for certain layers will make it easier to visualize if dealing with multiple image layers at once.

Once finished click "Set Layers!" and the layers will load onto the map.

The RTMA graphics are valid at the top of every hour, and typically are available on MesoWest roughly 75 minutes past the valid time (due to creation and processing). NEXRAD layers update an average of 12 times every hour, and typically the most current radar overlay displays with the most current observations.

Overlay and Observation Synchronizing

To ensure overlays and observations are synchronized in time, click "Time Options" on the left-panel of the map interface. Make sure "Auto Current Time" is unchecked.

To examine observations that likely were used in the RTMA analyses, set the time to 12 minutes past the desired hour. Then set "Report in last" to 24 min, uncheck the "Auto Refresh" option, and check the "Restrict Time Window" option and set to 3 minutes.

*Important Notes:

1) RTMA overlays are available for the top of the hour only. The map interface currently does not check to see if the selected time is synchronized with the overlays.
2) For consistency with our current software, the RTMA grids have been resampled to a 0.066 degrees latitude by 0.066 degrees longitude grid (roughly 7 km resolution).