CW3E 2022-23 Winter (Dec – Feb) Recap

March 8, 2023

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Wet Winter Helped Alleviate Drought Conditions and Produced Massive Snowpack

  • A family of 9 ARs made landfall between 26 Dec and 19 Jan and brought about half the of California’s precipitation during these three weeks.
  • Parts of the Central and Southern Sierras and some transverse ranges received 60+ inches.
  • Much of Central California received 100-150% of water year normal precipitation. Northeast and southeast California have received 50% or less of water year normal precipitation.
  • According to the US drought monitor there has been 3-5 class improvement in drought conditions over Central California and at least a class drought improvement over much of California.
  • Winter precipitation eliminated the 3-year drought deficit in 13% of the state.
  • SWE in the Southern Sierra went from 14% of April 1st at the beginning of December to 198% of April 1st SWE at the end of February.
  • By Mar 1, 9 reservoirs exceeded the historical average capacity, up from 1 on Dec 1 2022.
  • Water storage (reservoir +snowpack) in the Western Sierras increased from four-fold, with the greatest gains in the Southern Sierras.
  • As part of AR Recon there were 33 Intensive Observing Period (IOPs) which included 25 C130 flights, 18 GIV flights and the release of 1,186 dropsondes.
  • Precipitation and SWE totals during this winter are similar to Dec 2016– Feb 2017, with differences in the spatial patterns. In particular, northern CA received more precipitation in 2017 than this current winter.