715
FXUS66 KSTO 081929
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
1229 PM PDT Thu May 8 2025

.Discussion...

.Synopsis...
Dry and increasingly warm weather is expected into the weekend,
as well above normal high temperatures peak on Friday and
Saturday. Widespread Minor HeatRisk and areas of Moderate HeatRisk
are anticipated as a result. A pattern change to cooler and
unsettled weather is then expected moving into early next week.
This will bring chances for rain/mountain snow showers and
isolated thunderstorms to interior NorCal as well as periods of
breezy to gusty winds.

&&

.Key Messages...

* Today - Saturday:
 -Periodic late day breezy onshore winds.
 -Dry and warm weather with temperatures 10-15 degrees above
  normal under upper level ridging, peaking on Friday and
  Saturday.
 -Areas of Moderate HeatRisk across the Central Valley Friday-
  Saturday. Probability of high temperatures 90 degrees F or
  higher: 60-90% throughout the Valley Friday-Saturday.

* Sunday - Tuesday:
 -A trend toward cooler and more unsettled weather is expected,
  with a weather system arriving Sunday into early next week.
 -Gusty southerly winds Sunday, remaining breezy Monday and
  Tuesday. Probability of gusts 40 mph or higher: 40-70% northern
  and western Sacramento Valley, and northeast foothills on Sunday.
 -Rain and mountain snow chances expected as the system moves
  through.
 --48-Hour Probability of Rain > 0.25": 30-60% across northern
  Sacramento Valley and along Sierra. 5-15% remaining Valley
  locations, Delta, and foothills.
 --Isolated Thunderstorm Probability: 10-25% Monday and Tuesday,
  highest across north/central Sacramento Valley and along higher
  terrain.
 --48-Hour Probability of Snowfall > 4": 20-50% along
  Sierra/southern Cascades above 5500 feet.

* Mid to Late Next Week:
 -Progressive west-northwesterly flow aloft expected.
 -Generally dry weather, with temperatures warming to near normal.

.Changes from previous forecast...
 -Notable variance in the track of the incoming weather system,
  leading to some uncertainty in the magnitude of potential
  precipitation and wind impacts.
 -Some elevated fire weather concerns Sunday as winds increase
  ahead of the approaching system.


&&

.AVIATION...
VFR conditions prevail across interior NorCal next 24 hours.
Surface winds generally below 12 knots across Valley TAF sites.
Onshore flow in the Delta with surface gusts 15-20 knots. Diurnal
winds in the mountains with surface gusts generally below 20
knots.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$