FNUS21 KWNS 191640 FWDDY1 Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1139 AM CDT Thu Mar 19 2026 Valid 191700Z - 201200Z ...CRITICAL FIRE WEATHER AREA FOR CENTRAL AND EASTERN WYOMING... The Elevated area over the northern High Plains was expanded slightly northward into eastern portions of Montana, North Dakota, and South Dakota. This subtle expansion is commensurate with the latest extent of forecast guidance wind/RH reflecting more robust, through time and space, boundary layer mixing across this area. As was previously mentioned, eastern portions of the Snake River Valley in Idaho are expected to reach elevated wind/RH thresholds this afternoon. After reviewing additional fuels guidance across the area in light of the hot and dry conditions, the Elevated area was expanded to include this area as well. All other areas remain on track with poor overnight RH recoveries across much of Intermountain West going into today. This will extend burn periods across much of the southern two-thirds of the western US as this early season heat wave continues. Additional details can be found in the previous forecast discussion. ..Stearns/Williams.. 03/19/2026 .PREV DISCUSSION... /ISSUED 0125 AM CDT Thu Mar 19 2026/ ...Synopsis... Upper-level riding will persist across the Southwest with strong northwesterly upper-level flow remaining in place across the northern Rockies and central CONUS. This will support a continued downslope regime across the central/northern High Plains and western Wyoming Basin, with elevated to critical fire weather conditions expected amid strong west-northwest surface winds and very low RH values. Elsewhere, strong surface winds and reduced RH are expected to yield elevated fire weather conditions across portions of central/southern Oregon. ...Central/Northern High Plains... Anomalously strong upper-level ridging will persist across the Southwest today with strong upper-level northwesterly flow in place across the central/northern Rockies. At the surface, high pressure across the Intermountain West will combine with a low pressure system shifting southeastward across the Canadian Prairies to support west-northwesterly downslope winds of 20-25 mph and reduced RH values of 10-15% across portions of central and eastern Wyoming. With persistent dry/windy conditions continuing to aid in the maintenance of receptive fuels, these conditions are expected to support critical fire weather conditions this afternoon. While the strongest low-to-mid level flow is forecast to be displaced farther north, deep boundary layer mixing may still support occasional wind gusts to 30-35 mph across this area. Elevated fire weather concerns are also expected across adjacent regions, including much of the Wyoming Basin eastward into portions of northern Colorado, southwestern South Dakota, and northeastern Nebraska where sustained westerly surface winds of 15-20 mph and reduced RH of 10-15% are forecast amid the downslope wind regime. Elevated highlights have also been expanded farther north and east into much of southern Montana given similar forecast meteorological conditions and recent wildfire activity noted in the region. ...Oregon... Just west of the upper-level ridge axis, a strengthening surface pressure gradient is forecast to yield west-southwesterly sustained surface winds of 10-20 mph with RH values falling to 10-20% this afternoon across portions of central and southeastern Oregon with temperatures forecast well above normal. This combination of hot, dry, and windy conditions is expected to support elevated fire weather concerns prior to green up. ...Eastern Idaho... Latest high-res guidance depicts sustained westerly to southwesterly surface winds of 10-20 mph developing within the Snake River Valley through today amid a tightening surface pressure gradient. While RH values are forecast to drop to 15-25%, marginal fuel receptiveness is expected to preclude widespread fire weather concerns. ...Please see www.spc.noaa.gov/fire for graphic product... $$