


Fire Weather Outlook Discussion
Issued by NWS
Issued by NWS
048 FNUS22 KWNS 291956 FWDDY2 Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Sun Jun 29 2025 Valid 301200Z - 011200Z ...Northwest... Northern extent of isolated dry thunderstorm threat was trimmed owing to expected decrease in thunderstorm intensity/lightning production late Monday, closer to the Columbia Gorge. Otherwise, forecast (see below) remains on track. ...Great Basin... Advancing mid-level trough into the Western U.S. with attendant increasing mid-level winds atop a very dry/well-mixed boundary later will support Elevated fire weather conditions across portions of central and eastern Nevada Monday. Sustained south winds of around 15 mph combined with afternoon relative humidity of 10-15 percent along with dry fuels will increase wildfire spread potential. ...Southwest and Upper-Colorado River Basin... Shower and thunderstorm development is expected along higher terrain Monday afternoon as monsoon moisture advances into the Great Four Corners Region. A few dry thunderstorms are expected across southwest Colorado, western New Mexico and into the White Mountains of southeast Arizona. Slow thunderstorm motions in proximity to a Four Corners high, a marked increase in monsoon moisture magnitude and relative humidity into the region through midweek along with improving fuel indices should limit potential spread of ignitions. ..Williams.. 06/29/2025 .PREV DISCUSSION... /ISSUED 0204 AM CDT Sun Jun 29 2025/ ...Synopsis... As mid-level ridging builds over the western US, a weak subtropical low will deepen along the western periphery of the ridge across CA Monday. The building mid-level heights and approach of the upper trough will allow robust mid-level moisture to shift northward across portions of the West. ...Northwest... Heating across the higher terrain, coupled with weak ascent from the approaching upper trough will allow for isolated to widely scattered thunderstorms across northern CA and southern OR Monday afternoon and evening. Dry sub-cloud layers with steep lapse rates below 500mb will support a mixed wet/dry thunderstorm environment. Given the potential for dry lightning atop receptive fuels, an IsoDryT area has been added across parts of the Northwest where fire starts are possible. ...Great Basin... Farther south, beneath the upper ridge, very hot surface temperatures are expected over parts of NV and western UT. While surface winds are not expected to be overly strong, widespread RH values below 15% will be present. Occasional 15 mph wind gusts on a local basis and the hot/dry conditions could support a few hours of locally elevated fire-weather potential over dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... $$