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...

$$