Marine Weather and Tide Forecast for Geyserville, CA

DISCUSSION

...Today-Thursday...

A digging trough will continue to push southward through the Pacific Northwest and toward the Great Basin today into Thursday.
Light rain/mountain snow showers remain possible from Highway 50 northward through early Thursday morning, but forecast accumulations continue to dwindle with highest expected totals of 0.1"-0.25" primarily along the Sierra/southern Cascades and Shasta County mountains. Otherwise, dry and cool weather is expected to prevail elsewhere today and Thursday.

As the trough ejects eastward into Thursday, gusty north to east winds are expected to develop late this evening in the northern Sacramento Valley before spreading through the remainder of the Valley and Delta overnight into Thursday. Current NBM probabilities of wind gusts greater than 40 mph have increased to 40-60%, with highest chances favoring the central and southern Sacramento Valley along and west of Interstate 5 and north of Interstate 80. As a result, a Wind Advisory is now in effect for the Sacramento Valley and Delta from 5 am Thursday morning through 11 pm Thursday night. Strongest Valley wind gusts are anticipated through Thursday afternoon before gradually decreasing with downslope east- northeast wind gusts up to 45 mph along the Sierra then expected to develop Thursday evening into early Friday morning.

...Friday-Saturday...

As the midweek system continues its eastward trek through the end of the week, breezy north winds are likely to persist on Friday before trending lighter into the early weekend. Dry weather is expected to persist on Friday and Saturday as a brief period of ridging aloft builds in over the weekend. This ridging will allow temperatures to return to near to above normal through the first half of the weekend with some Minor HeatRisk possible on Saturday from Sacramento southward.

Sunday into Next Week

Ensemble guidance continues to indicate another deepening trough arriving Sunday into early next week, but notable timing differences between ensemble suites persist at the moment. In general, a return to active weather is anticipated Sunday into early next week, however; there is potential for precipitation onset to be delayed until Sunday evening/Monday morning.
Regardless, increasing chances for rain/mountain snow, isolated thunderstorms, and periods of breezy onshore winds are anticipated by at least early next week. At this time, NBM probabilities for precipitation greater than 1" remain around 50-70% for the mountains/foothills and 30-50% across the Valley/Delta. Snow levels are currently forecast remain around 5500-6500 feet, with most accumulations remaining above 6000 feet.

AVIATION

General VFR conditions at TAF sites next 24 hours. A weak system will bring isolated light precipitation over the northern Sacramento Valley and mountains/foothills after through 12Z Thursday with a 5-10% chance for isolated mountain thunderstorms which may lead to periods of MVFR/IFR conditions. Gusty northerly winds develop after 09Z-12Z Thursday with gusts of 25-35 kts in the Valley. Northeast to east wind gusts of 20-40 kts in the foothills and mountains.

STO WATCHES/WARNINGS/ADVISORIES
Wind Advisory from 5 AM to 11 PM PDT Thursday for Carquinez Strait and Delta-Central Sacramento Valley-Northern Sacramento Valley-Southern Sacramento Valley.