Sunrise 5:42 AM   Sunset 8:38 PM Moonrise 2:16 AM   Moonset 6:10 PM

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FXUS66 KSTO 032034 AFDSTO

Area Forecast Discussion National Weather Service Sacramento CA 134 PM PDT Wed Jul 3 2024

SYNOPSIS
Widespread Major to Extreme HeatRisk into the middle of next week. Critical fire weather conditions in the Sacramento Valley and adjacent foothills through this evening.

Key Points - Long-duration, major heat event into mid next week, impacting holiday outdoor events.
- Red Flag Warning is in effect for much of the Sacramento Valley and adjacent elevations below 3000 feet through this evening.
- Excessive Heat Warning remains in effect for the Valley, Delta and foothills through 11 PM Tuesday.
- Heat Advisory remains in effect for the Sierra, southern Cascades, and Burney Basin now until 11 PM Tuesday.
- High likelihood of this heat continuing through mid next week

Discussion
Northerly wind gusts of 15-30 MPH continue across portions of the western half of the Sacramento Valley and adjacent foothills early this morning. Winds will begin to taper off later this afternoon, becoming broadly light winds for the remainder of the week. Given the ongoing combination of gusty winds and very low humidities, our Red Flag Warning remains in effect for much of the Sacramento Valley and surrounding foothills below 3000 ft until 8 PM today. Even after the Red Flag Warning ends, very dry weather with hot temperatures continue the threat of elevated fire weather conditions this week into early next week.

Ensembles and clusters depict a strong, anomalous high pressure remaining overhead through the forecast period. This will result in a prolonged, dangerous heat event across the region. Daytime temperatures will range from 104 to 118 degrees in the Valley and adjacent foothills; peaking on Friday-Saturday. NBM probabilities indicate a 75-100% chance of high temperatures of 110 deg F or higher through the northern and central Sacramento Valley, and a 45 to 80% chance in the southern Sacramento and northern San Joaquin Valleys. Little relief is expected overnight with lows forecast in the upper 60s to mid 80s; warmest in the foothills.

As a result, widespread Major to Extreme HeatRisk is expected across interior NorCal. This level of HeatRisk is VERY DANGEROUS to anyone without proper hydration or adequate cooling. Strongly reconsider any outdoor activities during this prolonged heat event. DO NOT leave children or pets in unattended vehicles. Car interiors will quickly reach lethal temperatures in a matter of minutes. An Excessive Heat Warning remains in effect for the Valley, Delta, and foothills until 11 PM Tuesday. Additionally, a Heat Advisory remains in effect for the Sierra, southern Cascades, and Burney Basin from now until 11 PM Tuesday.

.EXTENDED DISCUSSION (Sunday THROUGH Wednesday)...

Cluster analysis continues to indicate a gradual eastward transition of the upper level ridge from the late weekend period into next week. As this occurs, broad southwesterly flow should begin to filter in aloft across interior NorCal. This will allow for the return of at least some weak onshore flow to the region into next week as well. Hot high temperatures of 108-114F are still anticipated through Sunday afternoon in the Valley and adjacent foothills, with a slight cool down closer to high temperatures in the 102-110F range into mid next week.

Additionally, with increasing Delta breeze influence early next week, some overnight relief from the heat will be possible, particularly in the Delta vicinity and into the Sacramento metro.
Low temperatures into the low to mid 60s will be possible in these areas through mid next week, with upper 60s to mid 70s still likely through the remaining Valley and adjacent foothills locations. This will correspond to widespread Major to Extreme HeatRisk on Sunday for areas outside of the Delta vicinity and Sacramento metro.
HeatRisk values then remain largely the same through the early week period, with a slight expansion of the Moderate risk area into the northern San Joaquin and central Sacramento Valleys and throughout the mountains.

AVIATION

VFR conditions expected across interior NorCal next 24 hours. Breezy northerly Sacramento Valley winds through 00z with occasional gusts to 20 kts. Increasing south to west gusts to 20 kts in Delta and immediate vicinity through 06z.

STO WATCHES/WARNINGS/ADVISORIES
Excessive Heat Warning until 11 PM PDT Tuesday for Carquinez Strait and Delta-Central Sacramento Valley-Motherlode-Mountains Southwestern Shasta County to Western Colusa County-Northeast Foothills/Sacramento Valley-Northern Sacramento Valley-Northern San Joaquin Valley-Shasta Lake Area / Northern Shasta County- Southern Sacramento Valley.

Red Flag Warning until 8 PM PDT this evening for Carquinez Strait and Delta-Central Sacramento Valley in Glenn, Colusa, Yuba, Northern Sutter, and Butte County Below 1000 Ft-Eastern Mendocino NF-Eastern Portion of Shasta/Trinity NF-Northern Sacramento Valley to Southern Tehama County Line Below 1000 Ft- Northern Sierra Foothills from 1000 to 3000 Ft. Includes portions of Shasta-Trinity and Butte Units-Southeast Edge Shasta- Trinity NF and Western Portions of Tehama-Glenn Unit-Southern Sacramento Valley in Yolo-Sacramento Far Western Placer, southern Sutter and Solano County Below 1000 Ft.

Heat Advisory until 11 PM PDT Tuesday for Burney Basin / Eastern Shasta County-West Slope Northern Sierra Nevada-Western Plumas County/Lassen Park.

Sacramento #4
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Wed -- 12:04 AM PDT     0.75 feet Low Tide
Wed -- 03:19 AM PDT     Moonrise
Wed -- 04:53 AM PDT     3.37 feet High Tide
Wed -- 05:46 AM PDT     Sunrise
Wed -- 02:15 PM PDT     -0.23 feet Low Tide
Wed -- 06:58 PM PDT     2.25 feet High Tide
Wed -- 07:06 PM PDT     Moonset
Wed -- 08:33 PM PDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION

Sacramento, Tide feet

Clarksburg #4
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Wed -- 03:20 AM PDT     Moonrise
Wed -- 03:44 AM PDT     3.37 feet High Tide
Wed -- 05:47 AM PDT     Sunrise
Wed -- 12:45 PM PDT     -0.23 feet Low Tide
Wed -- 05:49 PM PDT     2.25 feet High Tide
Wed -- 07:05 PM PDT     Moonset
Wed -- 08:33 PM PDT     Sunset
Wed -- 11:31 PM PDT     0.89 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION

Clarksburg, Tide feet

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