Lesley L. Smith – Extreme California Precip

All plots preliminary.

Extreme Precipitation in California

(CA DWR activity 6 subproject 2)

Re. OLR-based MJO index "mjoindices" from https://github.com/cghoffmann/mjoindices:

All nClimDiv daily precipitation data from A.Hoell; all ERA5 OLR daily data from M.Gehne.

Daily PNA (https://psl.noaa.gov/data/timeseries/daily/PNA/) from NOAA PSL

Sample ERA-5 MJO (OMI) Plot November 2022 thru March 2023
where red star indicates a maximum California precip event: Jan 16, 2023

----------------------POSITIVE AND NEGATIVE PNA CASES------------------------------------

MJO phases conditioned by PNA (positive or negative) for lags: -15 days to -1 days
NorthCentral_CA and South_CA

ERA5 Anomalies corresponding to nClimDiv Precip exceedances

MJO amplitude > 1 and Phases 4,5,6, or 7 at least 3 times between lags -15 days and -1 days
7-day accumulations California 67 percentile samples at lags -4 to 0 days, 20-yr climos
Positive_PNA

Additional plots, including negative PNA cases, here:
7-day North 67% 7-day South 67%

NOT MJO amplitude > 1 and Phases 4,5,6, or 7 between lags -15 days and -1 days
7-day accumulations California 67 percentile samples at lags -4 to 0 days, 20-yr climos
Positive_PNA

Additional plots, including negative PNA cases, here:
7-day North 67% 7-day South 67%
-----------------------end positive and negative PNA cases section-------------------

-----------------------------no PNA or ENSO cases------------------

MJO phases for lags -15 days to -1 day NorthCentral_CA and South_CA

NOT MJO Phases 4,5,6, or 7 between lags -15 days and -1 days
7-day accumulations
Northern_Central California 67 percentile samples at lags -4 to 0 days
Using 20-year antecedent climatologies

Additional plots here:
7-day North 67% 7-day South 67%

-----------------end no PNA or ENSO case sections-----------------
----------------------------16 binned PNA CASES-------------------------------------

Daily PNA standardized and binned into 16 0.5_increments

Relative frequency of precip events as a function of OMI MJO phase and single 7-day_mean PNA 'phase' for 0-day lag
North & Central CA and South CA

Relative frequency of precip events as a function of OMI MJO phase and running 7-day_mean PNA 'phase' for 6-day time-lag bins
North & Central CA and South CA

Relative frequency of precip events as a function of OMI MJO phase and daily PNA 'phase' for 5-day time-lag bins
North & Central CA

South CA

-------------------------------end 16 binned PNA cases section-----------
---------------------------------ENSO CASES----------------------------------------------------

Monthly ENSO Oceanic Nino Index (https://origin.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_v5.php) from NOAA CPC

Relative frequency of precip events as a function of OMI MJO phase and ENSO phase for 5-day time-lag bins
North & Central CA

South CA

-------------------------------end ENSO cases section----------------------------

ERA5 Anomalies corresponding to nClimDiv Precip exceedances

MJO amplitude < 1 for all times between lags -15 days and -1 days
7-day accumulations California 67 percentile samples at lags -4 to 0 days, using 20-yr climos

(No cases.)

MJO amplitude > 1 and Phases 4,5,6, or 7 at least 3 times between lags -15 days and -1 days
7-day accumulations California 67 percentile samples at lags -4 to 0 days, using 20-yr climos

Additional plots here:
7-day North 67% 7-day South 67%

Re. OMI Phase Frequency Anomaly with boostrapping for extreme CA precip with MJO leads and precip lags:
7-day accumulations:
Northern_Central & Southern California 67th percentile (MJOs radius>1) Two MJO Phases at a time

where anomalies obtained by subtracting the boostrap averages

All plots/analyses updated with lag-0 date corresponding to event onset rather than event end

ERA5 Anomalies corresponding to nClimDiv Precip exceedances
7-day, 14-day accumulations
Northern_Central California 67 percentile samples at lags -4 to 0 days
Using 20-year antecedent climatologies

Additional plots here:
7-day North 67% 14-day North 67% 7-day South 67% 14-day South 67%
7-day North 33% 14-day North 33% 7-day South 33% 14-day South 33%

Re. OMI Phase frequency and extreme CA precip with MJO leads and precip lags:
7-day, 14-day accumulations:
Northern_Central California 33rd percentile (MJOs radius>1) Two MJO Phases at a time

Northern_Central California 67th percentile (MJOs radius>1) Two MJO Phases at a time

Southern California 33rd percentile (MJOs radius>1) Two MJO Phases at a time

Southern California 67th percentile (MJOs radius>1) Two MJO Phases at a time

Re. OMI Phase frequency and extreme CA precip with MJO leads and precip lags:
7-day, 14-day accumulations and 5-day running mean
Northern_Central California 33rd percentile (MJOs radius>1) Two MJO Phases at a time

Northern_Central California 67th percentile (MJOs radius>1) Two MJO Phases at a time

Southern California 33rd percentile (MJOs radius>1) Two MJO Phases at a time

Southern California 67th percentile (MJOs radius>1) Two MJO Phases at a time

Re. OMI Phase frequency and extreme CA precip with MJO leads and precip lags:
7-day, 14-day accumulations:
Northern_Central California 33rd percentile (MJOs radius>1) One MJO Phase at a time

where the 7-day case included 414 nonoverlapping Nov-Mar precip-less-than-33-percentile points, 14-day case included 243 nonoverlapping Nov-Mar precip-less-than-33-percentile points;
with the Strong MJO condition reducing this to 27,39,38,22,22,37,27,40 7-day lag-0 Phase 1-8 points respectively
and 11,18,26,18,17,18,15,24 14-day lag-0 Phase 1-8 points respectively.

Northern_Central California 67th percentile (MJOs radius>1) One MJO Phase at a time

where the 7-day case included 292 nonoverlapping Nov-Mar precip exceedances, 14-day case included 166 nonoverlapping Nov-Mar precip exceedances,
with the Strong MJO condition reducing this to 12,19,31,29,12,31,19,24 7-day lag-0 Phase 1-8 points respectively
and 2,15,9,12,14,14,17,12 for 14-day lag-0 Phase 1-8 points respectively.

Southern California 33rd percentile (MJOs radius>1) One MJO Phase at a time

where the 7-day case included 418 nonoverlapping Nov-Mar precip-less-than-33-percentile points, 14-day case included 256 nonoverlapping Nov-Mar precip-less-than-33-percentile points,
with the Strong MJO condition reducing this to 28,31,38,22,21,33,34,35 7-day lag-0 Phase 1-8 points respectively
and 24,20,21,13,22,20,21,23 for 14-day lag-0 Phase 1-8 points respectively.

Southern California 67th percentile (MJOs radius>1) One MJO Phase at a time

where the 7-day case included 276 nonoverlapping Nov-Mar precip exceedances, 14-day case included 153 nonoverlapping Nov-Mar precip exceedances,
with the Strong MJO condition reducing this to 13,18,24,14,21,18,30,21 7-day lag-0 Phase 1-8 points respectively
and 8,7,18,9,10,12,10,15 for 14-day lag-0 Phase 1-8 points respectively.

Northern_Central California 67th percentile (MJOs radius>1) One MJO Phase at a time

Southern California 33rd percentile (MJOs radius>1) One MJO Phase at a time

Southern California 67th percentile (MJOs radius>1) One MJO Phase at a time

Re. bandpass-filtered OLR anomaly and extreme CA precip with OLR leads and precip lags:
7-day, 14-day accumulations:
Northern_Central California 33rd percentile

Northern_Central California 67th percentile

Southern California 33rd percentile

Southern California 67th percentile

Re. 250hPa geopotential height anomaly and extreme CA precip with geopotential_height leads and precip lags:
7-day, 14-day accumulations:
Northern_Central California 33rd percentile

Northern_Central California 67th percentile

Southern California 33rd percentile

Southern California 67th percentile

Re. OMI Phase frequency and extreme CA precip with MJO leads, El Nino and precip lags:
7-day, 14-day accumulations:

Northern_Central California 33rd percentile (MJOs radius>1)

Northern_Central California 67th percentile

Southern California 33rd percentile (MJOs radius>1)

Southern California 67th percentile

Re. OMI Phase frequency and extreme CA precip with MJO leads, La Nina and precip lags:
7-day, 14-day accumulations:
Northern_Central California 33rd percentile (MJOs radius>1)

Northern_Central California 67th percentile

Southern California 33rd percentile (MJOs radius>1)

Southern California 67th percentile

Re. OMI Phase frequency and extreme CA precip with MJO leads, ENSO Neutral and precip lags:
7-day, 14-day accumulations:
Northern_Central California 33rd percentile (MJOs radius>1)

Northern_Central California 67th percentile

Southern California 33rd percentile (MJOs radius>1)

Southern California 67th percentile