Marine Weather and Tide Forecast for Rancho Calaveras, CA

FXUS66 KSTO 090945 AFDSTO

Area Forecast Discussion National Weather Service Sacramento CA 145 AM PST Mon Dec 9 2024

SYNOPSIS
Breezy to gusty northerly winds today, along with slightly cooler high temperatures. Dry weather continues through mid-week before unsettled weather potential returns towards the end of the week.

DISCUSSION
Fog has once again developed this morning, mainly across the northern San Joaquin Valley. Visibilities are down to 1/4 mile at Stockton and Modesto AP, and are expected to continue through the early morning. Southeasterly winds at Stockton and Modesto is helping to push some of the fog into the the greater Sacramento Metro area, so the Fog Advisory's area has been extended further north. There is a distinct surface wind boundary, where northerly winds are reported just north of the Sacramento area, and southerly winds further south. We will continue to monitor the fog development overnight and adjust the advisory if needed.

The upper level trough that is responsible for the breezier northerly winds today is moving off into the northern Great Plains this morning, and a ridge is developing offshore. A fairly prominent ridge axis is extending into the Gulf of Alaska, with a trough axis extending from North Dakota into Idaho has orientated our upper level heights into a north-to-south direction, which will once again setup periods of gusty northerly winds across NorCal today. Best chances of wind gusts greater than 30 mph reside along the I-5 corridor, in the western Sacramento Valley, and the gaps and canyons of the foothills and mountains through early Tuesday morning. Tuesday morning winds may help alleviate some fog concerns, however the HRRR is still showing relatively high chances (40-75%) of morning fog developing again for the southern Sacramento Valley, Delta, and the northern Sacramento Valley.

Upper level ridging will continue to dominate the synoptic pattern through the short-term forecast period, resulting in mostly dry weather and near to slightly above normal high temperatures.
Valley locations can expect afternoon highs to be in the 50s to low 60s and higher elevations can expect upper 30s to low 50s.

.EXTENDED DISCUSSION (Friday THROUGH Monday)...

Weak upper ridging progged through interior NorCal Friday ahead of progressing upstream Pacific frontal system. Widespread frontal precip expected over interior NorCal Friday night through Saturday along with gusty wind. Snow levels lower to 4000 to 5000 feet Saturday with WPC QPF forecasting upwards of 1 to 2 feet of over higher elevations. Decreasing precip chances Sunday then another Pacific storm expected early next week.
Show more