Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0157 AM CDT Mon Sep 20 2021 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN CALIFORNIA... ...Synopsis... In the wake of an upper-level trough moving across the northern Rockies this morning, strong northwesterly flow aloft will extend from the Pacific Northwest into the central Great Basin. In response at the surface, high pressure will build into the northern Intermountain West increasing the pressure gradient across California. ...Northern California... Low-level northerly winds have increased across the region this morning per VAD wind profiles, indicating wind speeds over 40 mph around 1 kft above the ground. While the low-level winds will weaken and become more easterly through the afternoon, the surface pressure gradient will continue to increase through the morning, resulting in sustained surface winds over 20 mph. As heating and mixing commence at sunrise, RH values will fall below critical values by mid morning, resulting in a few hours of overlapping critical winds and RH values. ...Southern California... Locally elevated fire weather conditions are possible across Los Angeles, Ventura, and Santa Barbara counties as the surface pressure gradient supports offshore flow resulting in dry and breezy conditions in terrain-favored locations.