Fire Weather Outlook Discussion
Issued by NWS
Issued by NWS
427 FNUS28 KWNS 302202 FWDD38 Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0500 PM CDT Sun Jun 30 2024 Valid 021200Z - 081200Z Mid-level ridging is forecast to amplify significantly over the Pacific Coast through the extended forecast period. As the ridge builds, stronger flow aloft will be shunted to the northeast over parts of the Great Basin and northern Rockies through much of next week. While several perturbations will pass along the eastern periphery of the ridge, much of the Southwest will see extreme heat and dry conditions persist. Fire-weather concerns should increase through the period, especially as the upper ridge breaks down next weekend. ...Great Basin and Southwest... With ridge building through the first part of the extended period, very warm and dry surface conditions are likely to develop across parts of the Southwest. However, much of the stronger flow will remain displaced to the northeast, keeping surface winds modest through the first part of the work week. A slight increase in wind speeds is possible D4/Wed behind a dry cold front over parts of the northern Great Basin. 15-20 mph gusts and afternoon humidity of 10-20% could support several hours of near-critical fire-weather conditions within dry fuels. Flow aloft should weaken again toward the end of the week as the ridge temporarily strengthens. However, heading into the weekend, another weak trough should pass east of the ridge, potentially increasing dry and windy conditions over the Southwest. Through the reminder of the weekend into week 2, most guidance shows a decrease in ridge strength with a possible pattern shift toward western US troughing. Confidence in the result of this transition period remains very low as multiple model solutions are present. Some guidance shows an increase in showers and thunderstorm potential with increasing mid-level moisture, while others show a more substantial increase in hot, dry and windy conditions post ridging. Regardless of the outcome, an increase in fire-weather potential is very likely over parts of the Great Basin and Southwest, owing to the antecedent hot and dry period followed by ridge break down. ...CA... Beneath the upper ridge, extreme heat is expected over much of CA and the West Coast this week and into the weekend. While background winds should remain light, a low-level thermal trough may locally enhance dry and windy conditions across the northern and central parts of the state. A period of somewhat stronger northerly Sundowner winds may also develop D5/Thur into D6/Friday over southwest CA behind the weak trough passing to the east. While uncertain, locally higher fire-weather concerns could develop. ..Lyons.. 06/30/2024 ...Please see www.spc.noaa.gov/fire for graphic product... $$