RED FLAG POTENTIAL INDEX
NOAA's National Weather Service - Las Vegas, Nevada

These graphics are products designed to provide guidance information on the potential for, and areal coverage of, Red Flag Fire Weather conditions developing during the "Day 2" through "Day 4" forecast periods (i.e., tomorrow and the next two days) over the area for which NWS Las Vegas has forecast responsibility. The index ratings are based on forecasts of afternoon boundary layer relative humidity and mean 20-foot, 10-minute average winds. It is important to understand that the three states for which WFO Las Vegas provides Fire Weather support each define the threshold criteria for triggering a Fire Weather Watch or Red Flag Warning differently. Qualifying factors such as fuel moisture content, minimum duration requirements of the mean wind threshold, or the potential for "dry lightning" are not considered in the creation of the Red Flag Potential Index (RFPI) product. It simply provides a source of quick reference, visual information regarding the basic meteorological conditions which "might" signal the development of local Red Flag conditions.

These images are not intended to be used as stand alone products for operational planning and decision making. They are being created from a digital forecast data base as a resource for adding value to the traditional, official forecast products routinely generated by NOAA's National Weather Service. The product is refreshed twice per day, generally by 4 AM and 4 PM PDT.

RFPI - Day 2

RFPI - Day 3

RFPI - Day 4

RED FLAG POTENTIAL INDEX Color Key and Explanation Red (index value=6): "EXTREME RISK" Current forecast parameters suggest RH < 7% accompanied by a mean prevailing wind > 30 knots or gusts > 35 knots Orange (index value=5): "VERY HIGH RISK" Current forecast parameters suggest RH between 7-10% accompanied by a mean prevailing wind of at least 25 knots or gusts > 30 knots Yellow (index value=4): "HIGH RISK" Current forecast parameters suggest RH from 7-15% accompanied by a mean prevailing wind of at least 20 knots or gusts > 25 knots Green (index value=3): "MODERATE RISK" Current forecast parameters suggest low RH (< 15%) and/or a mean prevailing wind of at least 20 knots or gusts > 25 knots Blue (index value=1-2): "LOW RISK" Current forecast parameters suggest low RH (<15 %) with wind less than 20 knots or RH > 15% with winds up to 30 knots Purple (index value=0): "NEGLIGIBLE RISK" Neither prevailing wind nor minimum RH are forecast to approach threshold criteria for Red Flag conditions (All locations outside the WFO Las Vegas area of forecast responsibility are colored gray.)