NWS Louisville Doppler Radar All Tilts Reflectivity

Cold Front Moving Through the Northeast U.S. Monday; Atmospheric River to Impact the Pacific Northwest Midweek

A cold front will cross the Great Lakes and Northeast U.S. through Monday with gusty winds and areas of rain showers. A strong atmospheric river is expected to move into the Pacific Northwest by midweek bringing a threat for moderate to heavy rainfall, gusty winds, and mountain snows for parts of Washington, Oregon, northern California, and the Sierra Nevada. Read More >

NWS Doppler Radar (WSR-88D) Example Products

With NWS Doppler radar, all elevation angles (tilts) within a particular volume scan can be viewed very quickly using the "All Tilts" product. For example, in volume coverage pattern (VCP) 212 (i.e., radar's antenna scan strategy), the radar scans 14 elevation angles in about 4 minutes. From the data, forecasters can quickly assess the full vertical structure of thunderstorms, such as storm height, deep high reflectivity cores, storm tilt which is related to vertical wind shear and storm type, and other information. It greatly assists the severe storm warning decision making process.

Above is All Tilts reflectivity data at 2014 UTC on March 2, 2012. Only every other tilt is shown (i.e., only 7 images instead of 14). The first (lowest) image at 0.5 degrees elevation shows numerous severe storms, while the last (highest) image at 19.5 degrees overshoots the top of most storms and shows only anvil debris near the radar. Storm tilt to the southeast with height is evident for two supercells over southern Indiana with a deep core of high reflectivity and hail aloft. In addition, the eastern supercell near the Scott-Clark County, IN line shows a bounded weak echo region (BWER) aloft (small area of lower reflectivity values), which denotes the location of the rotating updraft (mesocyclone) in the storm. This cell produced a strong tornado in Clark County.