Marine Weather and Tide Forecast for Discovery Bay, CA

DISCUSSION

Today
Weak ridging and westerly flow aloft will promote above-normal temperatures and Minor HeatRisk across the area today. Highs are expected to be in the upper 80s to low 90s across the Valley, with mountain/foothill highs in the upper 70s to 60s. North winds will be breezy in the northern/central Sacramento Valley, with gusts 15 to 25 mph, increasing closer to 30 mph by this evening. Further south, the Delta Breeze will bring westerly winds into the southern Sacramento Valley and northwest winds into the northern San Joaquin Valley this afternoon, before winds shift to the north overnight. Relative humidities will begin to trend lower today into the weekend as north to northwest winds increase with daytime RH values in the low teens to mid 20s in the Valley.

Saturday through Monday
Ensemble guidance depicts a trough digging into the Great Basin this weekend, which will increase north to northwest winds through the Valley through Monday. Winds will begin to pick up Friday night in the northern/central Sacramento Valley before strengthening Saturday night through Sunday. Daytime relative humidities are expected to fall into the single digits to low teens during this time period leading to critical fire weather conditions. As a result, a Red Flag Warning has been issued for the Valley & Delta from 5 AM Saturday until 8 PM Monday. Sustained wind gusts are forecast between 20 to 30 mph with gusts 35 to 45 mph. Gusts may approach 50 mph through the Delta and far western Sacramento Valley. Winds will begin to trend weaker on Monday, however daytime relative humidities are still expected in the single digits. Overnight maximum humidities will be slow to recover Sunday night into Monday, with values in the 30s to 50s.
Over the mountains and through gaps and canyons, north to east winds will gust 35 to 50 mph Sunday and Monday as well.

Probability of Valley Wind Gusts > 40 mph: - Saturday's Chances: 20-50% - Sunday's Chances: 65-95% - Monday's Chances: 10-35%

...Tuesday-Thursday...
Heights begin to rise as the trough exits the Great Basin which will lead to gradually warming temperatures through midweek. Minor HeatRisk will continue to be widespread, with Valley high temperatures pushing into the mid to upper 90s. Daytime minimum RHs will remain in the low teens to low 20s below 1000 ft (potentially into the single digits), additionally daytime values in the mountains and foothills will be in the 20 to 30s as well.
The continued low RHs combined with the warmer temperatures may bring elevated fire weather conditions to the Valley next week.

Please continue to practice fire safety and monitor your latest forecast to stay up to date at weather.gov/sacramento

AVIATION
VFR conditions are expected over the next 24 hours. North- northwest 8 to 15 kts and gusts 20-25 kts through Saturday 18z with increasing winds over the northern & central Sacramento Valley after 00z Saturday with gusts 20-35 kts. West winds over the Sierra until 03z Friday, weakening and turning to the east overnight.



STO WATCHES/WARNINGS/ADVISORIES
Red Flag Warning from 5 AM Saturday to 8 PM PDT Monday for Butte County Below 1000 ft-C. San Joaquin County including Stockton-C.
Solano County including Fairfield-C. Stanislaus County including Modesto-C. Yolo/NE Solano including Woodland-Central Colusa County Incl. I-5-Central Glenn Co & Interstate 5-Eastern Colusa County-Eastern Glenn County-N. Sac Valley in Tehama County-NE San Joaquin Valley Below 1000 ft-SW Solano County including Vallejo-Sac Metro/W. El Dorado/Amador County-Sacramento County Delta-San Joaquin County Delta-Shasta Metro-Sutter/Yuba counties below 1000 ft-Tracy Triangle Below 1000 ft-W. Stanislaus County Above 1000 ft & I-5-W. Yolo County including Capay/I-505.