Hydrologic Outlook 12/19/2024 20:53 for California areas

ESFMTR AN ACTIVE STORM TRACK ACROSS NORTHERN CALIFORNIA WILL BRING MODERATE RAINFALL AND AN INCREASED POTENTIAL FOR RAPID RIVER RISES ON NORTH BAY CREEKS AND STREAMS * WHATThe storm door is wide open with a very active storm track forecast to impact Northern California. Wet and unsettled weather will bring periods of light to moderate rainfall to the region with the biggest impact expected over the North Bay. The first couple of storms that are forecast to move across the North Bay Saturday and again on Sunday, will likely prime the soils resulting in quicker and more noteworthy rises of area streams and creeks by the time the third storm moves in. This third storm that is expected to impact the North Bay on Monday and Tuesday is gearing up to be the strongest and wettest of the series. The higher elevations of the North Bay will likely see around 2.0 to 4.0 inches of precipitation while North Bay valleys see around 1.30 to 3.0 inches. Main stem rivers are forecast to remain below flood stage; however, the exceedance probabilities (of rising above flood stage) across the North Bay show a high potential for exceeding flood thresholds early next week. The Russian River at Guerneville - GUEC1 has a 39% of exceeding the Action/Monitor stage and a 34% of exceeding the Minor Flood stage . SHEC1- Napa near Saint Helena has a 43% of exceeding the Action/Monitor stage and a 20% of exceeding the Minor Flood stage. APCC1- Napa near Napa has a 30% of exceeding the Action/Monitor stage and a 11% of exceeding the Minor Flood stage . A few other rivers to keep an eye on that show higher probability of reaching Action/Monitor or Minor flood stage according to the latest CNRFC forecast are CTIC1 - Laguna De Santa Rosa at Stony Pt Rd near Cotati has a 80-95% probability of reaching Action/Monitor Stage and a 40-70% probability of reaching Minor flood stage as early as Saturday with chances increasing as the weekend progresses. MWEC1 - Mark West Creek at Mirabel Heights now has a 91% probability of reaching Action/Monitor Stage and a 52% probability of reaching Minor flood stage on Tuesday. GEYC1 - Russian River at Geyserville has a 52% probability of reaching Action/Monitor Stage and a 41% probability of reaching Minor flood stage on Tuesday. * WHERESonoma and Napa Counties. Latest model guidance suggests the North Bay will receive the greatest accumulation of precipitation with the heaviest rainfall expected over the North Bay coastal range and mountains. * WHENSaturday through Wednesday. Light to Moderate rainfall expected over the North Bay Saturday through Tuesday. The heaviest rainfall accumulation is expected Monday into Tuesday. * ADDITIONAL DETAILS...In addition to the moderate rainfall and localized ponding of water in low-lying or poorly drained areas, such as freeway offramps. Locally strong and gusty winds may result in downed trees, and potential power outages. Confidence is high that we will receive rainfall from this system however, confidence is moderate with respect to the exact location and timing of the most intense rainfall. Details regarding this storm will likely change as the system nears. Therefore, stay tuned to the latest forecast for the most up to date weather information.