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Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
229 PM EST Mon Dec 22 2025
Day 3
Valid 12Z Wed Dec 24 2025 - 12Z Thu Dec 25 2025
...THERE IS A HIGH RISK FOR EXCESSIVE RAINFALL ACROSS SOUTHERN
CALIFORNIA...
2100 UTC UPDATE:
The primary change to the previous day 3 Excessive Rainfall Outlook was to add a high risk area along the west to east Transverse Range region of Southern California after collaboration with WFO
LOX. Anomalous 850-700 mb moisture flux...5+ standard deviations above the mean...will impact Southern CA late day 2 into day 3 ahead of the amplifying mid to upper level trof off the CA coast. The heavy rainfall totals for Southern CA will likely occur over an 18 hour period, with widespread 4-7 inch totals, with isolated max amounts of 9"+. Expect a well defined south to north precip band
in this anomalous moisture flux axis with hourly rainfall rates of.50-1.5"+ likely. The potential for high hourly rainfall totals
will accentuate runoff over soil that is relatively dry and or over recent burn scar areas. This will pose a significant threat of flash flooding, landslides, rock falls and mud slides. (...)
#CAwx #AtmosphericRiver #SouthernCalifornia #LosAngelesCounty #VenturaCounty #SantaBarbaraCounty
Excessive Rainfall Discussion
NWS Weather Prediction Center College Park MD
229 PM EST Mon Dec 22 2025
Day 3
Valid 12Z Wed Dec 24 2025 - 12Z Thu Dec 25 2025
...THERE IS A HIGH RISK FOR EXCESSIVE RAINFALL ACROSS SOUTHERN
CALIFORNIA...
2100 UTC UPDATE:
The primary change to the previous day 3 Excessive Rainfall Outlook was to add a high risk area along the west to east Transverse Range region of Southern California after collaboration with WFO
LOX. Anomalous 850-700 mb moisture flux...5+ standard deviations above the mean...will impact Southern CA late day 2 into day 3 ahead of the amplifying mid to upper level trof off the CA coast. The heavy rainfall totals for Southern CA will likely occur over an 18 hour period, with widespread 4-7 inch totals, with isolated max amounts of 9"+. Expect a well defined south to north precip band
in this anomalous moisture flux axis with hourly rainfall rates of.50-1.5"+ likely. The potential for high hourly rainfall totals
will accentuate runoff over soil that is relatively dry and or over recent burn scar areas. This will pose a significant threat of flash flooding, landslides, rock falls and mud slides. (...)
#CAwx #AtmosphericRiver #SouthernCalifornia #LosAngelesCounty #VenturaCounty #SantaBarbaraCounty