Drought in the West: Short-Range Drought in the West: Short-Range Forecasts to Assist with Local and Forecasts to Assist with Local and

Regional PlanningRegional PlanningDouglas Le ComteDouglas Le Comte

NOAA/CPCNOAA/CPC

Association of Bay Area Governments: Water/Land Use Association of Bay Area Governments: Water/Land Use CollaborationCollaboration

August 7, 2008August 7, 2008

OutlineOutline

• Current Drought SituationCurrent Drought Situation

• Medium Range and Seasonal ForecastsMedium Range and Seasonal Forecasts

• Historical PerspectiveHistorical Perspective

• Climate Change Climate Change

Dust Event Honda Proving Center Dust Event Honda Proving Center June 4 2008 Cantil CAJune 4 2008 Cantil CA

Water Year PrecipitationWater Year Precipitation

http://www.hprcc.unl.edu/maps/currenthttp://www.hprcc.unl.edu/maps/current//http://www.calclim.dri.edu/anommaps.htmlhttp://www.calclim.dri.edu/anommaps.html

California Climate Data ArchiveCalifornia Climate Data Archive

High Plains Regional Climate CenterHigh Plains Regional Climate Center

Wet Winter…Dry SpringWet Winter…Dry Spring

http://www.cpc.ncep.noaa.gov/products/global_monitoring/precipitation/global_precip_accum.shtmlhttp://www.cpc.ncep.noaa.gov/products/global_monitoring/precipitation/global_precip_accum.shtml

Recent U.S. Drought MonitorRecent U.S. Drought Monitor

Western Snowpack 2008 vs 2007Western Snowpack 2008 vs 2007

http://www.wcc.nrcs.usda.gov/snowcourse/snow_map.htmlhttp://www.wcc.nrcs.usda.gov/snowcourse/snow_map.html

Western Streamflow ForecastsWestern Streamflow Forecastshttp://www.wcc.nrcs.usda.gov/cgibin/sssf.plhttp://www.wcc.nrcs.usda.gov/cgibin/sssf.pl

California Drought SummaryCalifornia Drought Summary(from Dep’t of Water Resources Executive Summary)(from Dep’t of Water Resources Executive Summary)

• Water Year precipitation = 85% of averageWater Year precipitation = 85% of average

• Runoff = 60% of averageRunoff = 60% of average

• Reservoirs = 75% of averageReservoirs = 75% of average

• For Northern Sierra, March-June = driest since For Northern Sierra, March-June = driest since records began in 1921 (3.4 in)records began in 1921 (3.4 in)

http://cdec.water.ca.gov/cgi-progs/reports/EXECSUMhttp://cdec.water.ca.gov/cgi-progs/reports/EXECSUM

Two Looks at the Current Drought:Two Looks at the Current Drought: How Bad? How Bad?

Multimodel Soil Moisture Multimodel Soil Moisture Percentiles (83 years of data)Percentiles (83 years of data)

Aug. 3, 2008Aug. 3, 2008 Palmer Hydro Drought IndexPalmer Hydro Drought Index

Arguably, the 4Arguably, the 4thth “worst” “worst” drought since 1900!drought since 1900!

http://www.ncdc.noaa.gov/oa/climate/research/prelim/drought/state-reg-moisture-status.htmlhttp://www.ncdc.noaa.gov/oa/climate/research/prelim/drought/state-reg-moisture-status.html

Historical Drought: River RunoffHistorical Drought: River Runoff since 1900 since 1900

http://meteora.ucsd.edu/cap/pdffiles/DroughtReport2008.pdfhttp://meteora.ucsd.edu/cap/pdffiles/DroughtReport2008.pdf

The Seasonal Drought OutlookThe Seasonal Drought Outlook

http://www.cpc.ncep.noaa.gov/products/expert_assessment/seasonal_drought.htmlhttp://www.cpc.ncep.noaa.gov/products/expert_assessment/seasonal_drought.html

Web Resources for Drought and ForecastsWeb Resources for Drought and Forecasts• Climate Prediction Center for Medium and Long Range Forecasts: Climate Prediction Center for Medium and Long Range Forecasts:

www.cpc.ncep.noaa.gov

• National Integrated Drought Informaton System for the new drought National Integrated Drought Informaton System for the new drought portal: portal: www.drought.govwww.drought.gov

• California Applications Program and the California Climate Change California Applications Program and the California Climate Change Center: Center: http://meteora.ucsd.edu/cap/http://meteora.ucsd.edu/cap/

• California Climate Tracker: California Climate Tracker: http://www.wrcc.dri.edu/monitor/cal-mon/index.htmlhttp://www.wrcc.dri.edu/monitor/cal-mon/index.html

Drought Impact Drought Impact ReporterReporter

droughtreporter.unl.edu

CPCCPCNIDISNIDIS

ENSO (El Nino-Southern Oscillation) Status: ENSO (El Nino-Southern Oscillation) Status: NeutralNeutral

http://www.cpc.ncep.noaa.gov/http://www.cpc.ncep.noaa.gov/

Thru Aug 3, 2008Thru Aug 3, 2008

http://www.bom.gov.au/climate/enso/indices.shtml

La Nina last La Nina last winterwinter

El Nino and La Nina El Nino and La Nina Winter (Jan-Mar) PrecipitationWinter (Jan-Mar) Precipitation

El NinoEl Nino

La NinaLa Nina

Frequency of Frequency of occurrenceoccurrence

A majority of ENSO forecasts indicate ENSO-neutral conditions through Northern Hemisphere spring 2009.

Pacific NiPacific Niño 3.4 ño 3.4 SST OutlookSST Outlook

Figure provided by the International Research Institute (IRI) for Climate and Society (updated 15 July 2008).

6-10 Day and 8-14 Day Rainfall6-10 Day and 8-14 Day Rainfall

http://www.cpc.ncep.noaa.gov/products/forecastshttp://www.cpc.ncep.noaa.gov/products/forecasts//

CPC Seasonal Precipitation ForecastsCPC Seasonal Precipitation Forecasts

http://www.cpc.ncep.noaa.gov/products/predictions/90dayhttp://www.cpc.ncep.noaa.gov/products/predictions/90day//

ASOASO SONSON

ONDOND NDJNDJ

CPC Winter OutlookCPC Winter Outlook

DJFDJF JFMJFM

Experimental University of Washington Experimental University of Washington ForecastsForecasts

http://www.hydro.washington.edu/forecast/monitor/outlook/index.shtml

Current Current RunoffRunoff

Forecast for Oct. 26, 2008Forecast for Oct. 26, 2008(Based on historical data)(Based on historical data)

ImprovementImprovementTendency for Tendency for improvement improvement based on this based on this experimental experimental forecast.forecast.

Palmer Drought Probabilities to October Palmer Drought Probabilities to October 20082008

Courtesy R. Tinker, CPCCourtesy R. Tinker, CPC

ClimateClimate

Division (C.D.)Division (C.D.) C. D. NameC. D. Name July 2008 PHDIJuly 2008 PHDIJuly 2008 PHDI July 2008 PHDI

PercentilePercentile

July 2008 July 2008 Nominal Drought Nominal Drought

Monitor (D. M.) Monitor (D. M.) EquivalentEquivalent

Like-Cases Like-Cases Chance for 1+ D. Chance for 1+ D.

M. Equivalent M. Equivalent Improvement by Improvement by

March 2009March 2009

Like-Cases Like-Cases Chance for Chance for

March 2009 PHDI March 2009 PHDI > 30> 30thth Percentile Percentile

(D0+ D.M. Equiv.)(D0+ D.M. Equiv.)

CA01CA01 North CoastNorth Coast -2.57-2.57 8.88.8 D2D2 72%72% 67%67%

CA02CA02 SacramentoSacramento -3.63-3.63 0.00.0 D4D4 60%60% 40%40%

CA03CA03 Northeast Northeast InteriorInterior -2.36-2.36 22.622.6 D0D0 36%36% 46%46%

CA04CA04 Central Central CoastCoast -2.29-2.29 18.118.1 D1D1 70%70% 70%70%

CA05CA05 San JoaquinSan Joaquin -3.99-3.99 3.23.2 D3D3 90%90% 50%50%

CA06CA06 South CoastSouth Coast -3.48-3.48 8.88.8 D2D2 53%53% 42%42%

CA07CA07 Southeast Southeast DesertDesert -3.38-3.38 15.915.9 D1D1 60%60% 60%60%

Palmer Hydrologic Drought Index (PHDI) StatisticsPalmer Hydrologic Drought Index (PHDI) Statistics for California Climate Divisionsfor California Climate Divisions

Potential March 2009 Conditions Based on July 2008 Conditions & July-March Changes Following Past July’s with Similar Conditions

Good odds for (Palmer) drought ending coastal areas next winterGood odds for (Palmer) drought ending coastal areas next winter

CFS* Model Winter ForecastCFS* Model Winter Forecast

Probability of Probability of Anomalous Anomalous Precipitation (as of Precipitation (as of Aug. 5)Aug. 5)

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/ensoforecast.shtmlhttp://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/ensoforecast.shtml

Tilt toward below Tilt toward below normal in CA and normal in CA and the SWthe SW

*Coupled (or Climate) Forecast *Coupled (or Climate) Forecast SystemSystem

Bottom line: Bottom line: History suggests History suggests significant relief significant relief unlikely before unlikely before December, and December, and forecasts for next forecasts for next winter are winter are ambivalent, but ambivalent, but some dynamic some dynamic models are tilting models are tilting dry.dry.

Climate Model Forecasts:PrecipitationClimate Model Forecasts:PrecipitationCalifornia Climate Change CenterCalifornia Climate Change Center

http://meteora.ucsd.edu/cap/cat2008_peak.htmlhttp://meteora.ucsd.edu/cap/cat2008_peak.html

Precipitation Precipitation forecast forecast uncertain for uncertain for next few next few decadesdecades

California Climate Model Forecasts: California Climate Model Forecasts: TemperatureTemperature

Temperatures Temperatures should keep should keep going upgoing up

Projected Annual Runoff 2041-2060Projected Annual Runoff 2041-2060

Less runoff for Less runoff for California and the California and the SouthwestSouthwest

““Prediction is very difficult, especially Prediction is very difficult, especially about the futureabout the future” ” Niels Bohr, Danish Niels Bohr, Danish

physicist (not Yogi Berra)physicist (not Yogi Berra)