CW3E AR Update: 8-10 January 2018 Post Event Summary

January 8, 2018

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Atmospheric river conditions brought widespread precipitation throughout California

  • A low pressure system developed off the CA coast on 7 January and interacted with tropical moisture to produce heavy precipitation over nearly all of CA
  • Nearly all of CA experienced AR conditions (IVT >250 kg m-1 s-1 and IWV >20 mm) for ~24 hours
  • The highest precipitation amounts were observed over the Coastal and Transverse Ranges, with some locations receiving over 200 mm of precipitation, making this and R-Cat 1 event

Click IVT or IWV image to see loop of GFS analysis

Valid 0000 UTC 5 January – 0000 UTC 10 January 2018

SSMI/SSMIS/ARMSR2-Derived Integrated Water Vapor (IWV)

Valid 0000 UTC 7 January – 1200 UTC 10 January 2018

NEXRAD Radar Reflectivity

Valid 0000 UTC 8 January – 1200 UTC 10 January 2018

Precipitation began over California around 400 UTC 8 January and lasted until early 10 January









Summary provided by B. Kawzenuk and F.M. Ralph; 12 PM PT Thursday 11 January 2018