Montana, here I come!

Regional Radar

Meteorlogix's regional radar uses the BASE REFLECTIVITY product from the National Weather Service WSR-88d Doppler radar network. The base reflectivity product is the best product for determining precipitation, as it incorporates data from four different angles: 0.5 deg, 1.5 deg, 2.4 deg, and 3.4 degrees. The base reflectivity information is available out to 124 nautical miles (approximately 140 statute miles). Resolution of the radar is 2 kilometers x 2 kilometers--which equates to approximately 1.5 square miles.

The regional radar displays precipitation in 16 display levels. Special automated analysis techniques are used to validate the echo returns from the radar sites and thus display only precipitation reaching the ground, while also reducing ground clutter and atmospheric returns. The displayed reflectivity levels range from 0 dbZ to a maximum of 75 dbZ. Additionally, and rain/snow "mask" is applied to the 16 level image. This "mask" uses three sets of 16 colors, corresponding to either rain, a rain/snow mix, or to all snow. This type of image provides an instant view of the likely form of the precipitation, along with its intensity.

The snowfall information is limited to a radius of 80 to 100 miles due to altitude considerations. In winter, the atmosphere is colder and precipitation occurs at lower altitudes than in summer. Thus, a radar beam shooting straight out from the site often "overshoots" snowfall due to the straight radar beam going out over the curved surface on the earth.

The radar site identifiers have their activity status represented in three distinct colors:

WHITE — active and sending valid data

YELLOW — active, but sending some data that has not been completely verified.

RED — inactive due either to the site being shut off, mechanical failure, or weather-related malfunction.