####018003552#### FNUS21 KWNS 060638 FWDDY1 Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0138 AM CDT Sat Apr 06 2024 Valid 061200Z - 071200Z ...CRITICAL FIRE WEATHER AREA FOR THE SOUTHERN HIGH PLAINS... ...Synopsis... Widespread critical to extremely critical fire weather conditions are expected today across much of the southern High Plains. Early-morning water-vapor imagery depicts the gradual eastward translation of a robust upper trough over the western CONUS. An embedded shortwave trough, evident by an attendant mid-level jet streak in upper air analyses, is rounding the base of the trough and is forecast to reach the southern High Plains by around peak heating. Steady surface pressure falls are noted along the High Plains ahead of the approaching upper trough with rapid deepening of a lee cyclone expected by late morning across parts of CO/NE. Strengthening gradient winds in the vicinity of the surface low will promote widespread fire weather concerns - particularly behind a Pacific front/dryline as it mixes east across the High Plains through midday. Forecast guidance continues to show high probability for sustained winds between 20-30 mph from the Trans Pecos region of southwest TX to eastern CO/western KS. 00 UTC soundings and 06 UTC surface observations sampled very dry conditions within the low-level thermal ridge along the southern High Plains. This air mass will undergo further drying within the westerly downslope flow regime later today with RH minimums between 10-15%. Reports of wildfire activity over the past 24 hours across the southern Plains corroborates the rapid drying depicted in recent fuel guidance. Consequently, a high-end critical fire weather environment is expected across much of the southern Plains region. Extremely critical conditions are probable across southeast CO to southwest KS and into the OK Panhandle. Ensemble guidance suggests that sustained winds above 30 mph and sub-10% RH both reside within the top (bottom) 10th percentile of their respective distributions; however, observations from Friday afternoon show that conditions were windier/drier compared to what most guidance had depicted. This trend nudges confidence enough to warrant introducing an Extremely Critical risk area across the CO/KS/OK region where guidance has consistently shown the best signal for sustained extremely critical conditions over the past 48 hours. Regardless, wind gusts upwards of 45-55 mph will support transient extremely critical conditions further south into the TX Panhandle and west TX as well. ...Central KS... Isolated thunderstorms may develop across portions of central KS by early afternoon. Poor moisture return will likely yield high-based convection that may feature little precipitation. This activity is forecast to quickly move east along the dryline, followed by elevated to critical fire weather conditions. Consequently, lightning starts may be exacerbated by the rapid onset of fire weather conditions. ...Northern Plains... Another day of strong, 20-30 mph sustained winds is expected across the Dakotas into parts of MN and IA. Cooler temperatures within a residual continental air mass should keep RH values above elevated thresholds, but the breezy winds and cured fine fuels may support a wind-driven fire weather concern. ..Moore.. 04/06/2024 ...Please see www.spc.noaa.gov/fire for graphic product... $$