-- Discussion containing changed information from previous version are highlighted. --
469
FXUS66 KSTO 072100
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
200 PM PDT Fri Jun 7 2024

.SYNOPSIS...
-- Changed Discussion --
Slightly cooler but still above normal temperatures over the
weekend. Warmup expected early next week with Major HeatRisk for
the northern and central Sacramento Valley. Isolated high
elevation mountain shower/thunderstorm chances in the
afternoon/evening hours today and Saturday.
-- End Changed Discussion --

&&

.DISCUSSION...

-- Changed Discussion --
Key Points

- Areas of Moderate HeatRisk for today; Triple digits in the
  Northern and Central Sacramento Valley and adjacent Valley
  foothills, less hot in the Delta and Sacramento metro area with
  highs in the 80s to lower 90s.
- Slightly cooler this weekend with just some localized Moderate
  HeatRisk, mainly over the northern and central Sacramento
  Valley.
- Warm up expected early next week with well above normal
  temperatures. Moderate HeatRisk returns to much of the Valley
  and foothills on these days, with areas of Major HeatRisk in the
  northern and central Sacramento Valley.

Short-Term Discussion (Today THROUGH Monday)...

Current GOES-West visible satellite imagery shows clear skies and
abundant sunshine over much of interior northern California on
this Friday afternoon, with the exception of some cumulus clouds
that are developing over the Coast Range and southern Cascades.
Temperatures are currently trending approximately 2 to 10 degrees
cooler than this time yesterday afternoon, valid at 145 PM PDT as
upper level ridging continues to shift eastward, and southwest
flow influences the region. Forecast highs for this afternoon are
in the low 100s for the northern and central Sacramento Valley,
with sub-100s elsewhere. Increased onshore flow will be aiding in
keeping temperatures cooler in the Delta and vicinity. There is a
slight chance for a brief shower or thunderstorm this afternoon,
with a 10-15% probability, mainly over the southern Cascades.

For this weekend, slightly cooler but still above normal
temperatures are forecast. Mainly Minor HeatRisk is expected, with
just some isolated Moderate HeatRisk. Valley high temperatures
look to be in the upper 80s to mid 90s this weekend. With
increased onshore flow, periods of breezy conditions are expected
over the next few days, with onshore gusts of 15 to 25 mph in the
afternoon and evening hours, primarily across the Delta and into
the southern Sacramento Valley and northern San Joaquin Valley.
Additionally, a weak trough is expected to travel through the flow
pattern Saturday into Sunday, bringing the potential for isolated
high elevation mountain shower or thunderstorm chances in the
afternoon or evening, mainly on Saturday where there is a 15-25%
probability.

A warmup is then expected to early next week, with Moderate
HeatRisk returning on Monday, and localized Major HeatRisk in the
northern and central Sacramento Valley. The warmup continues into
part of the extended forecast period as well. Additionally,
area waterways continue to run fast and cold from snowmelt,
creating dangerous conditions for those seeking relief in rivers
and lakes next week.

To view the latest HeatRisk, please visit
www.wpc.ncep.noaa.gov/heatrisk/

To view current water temperatures, please visit
www.cnrfc.noaa.gov
-- End Changed Discussion --

&&

.EXTENDED DISCUSSION (Tuesday THROUGH Friday)...
-- Changed Discussion --
Ensemble guidance and cluster analysis generally indicate quiet
weather over the extended forecast period, with ridging creeping
in from the eastern Pacific and a closed low over southern
California mid-week. For much of the Valley on Tuesday and
Wednesday, there is a 55 to 85 percent probability of high
temperatures reaching or exceeding the 100 degree mark once again.
This translates to Moderate HeatRisk for most of the area, with
areas of Major HeatRisk in the northern and central Sacramento
Valley on Tuesday and Wednesday. Ensembles and clusters then
suggest some cooling for late week, although there is still
somewhat of a decent spread in forecast highs. Current forecast
has HeatRisk decreasing to mainly Minor with areas of Moderate for
Thursday and Friday.
-- End Changed Discussion --

&&

.AVIATION...
-- Changed Discussion --
VFR conditions prevail over interior NorCal over the next 24
hours. Southwest wind gusts of 15-25 kts in the Delta through 12Z
Saturday, and in the Sacramento Valley through around 06Z-09Z
Saturday. Northwest wind gusts 15-20 kts in the northern San
Joaquin Valley through 06Z Saturday. Slight chance of high
elevation mountain shower/thunderstorm through 03Z Saturday and
again after 18Z Saturday.
-- End Changed Discussion --

&&

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

&&

$$