U.S Drought Highlights Since October 2006 Douglas Le Comte NOAA/CPC 32nd Annual Climate Diagnostics and Prediction Workshop October 22-26, 2007 Morristown, TN, Sep. 12, 2007

Georgia gets tough on water use!

Outline Current Drought and 12-month EvolutionCurrent Drought and 12-month Evolution Drought in Historical PerspectiveDrought in Historical Perspective Selected Drought ImpactsSelected Drought Impacts Current Drought OutlookCurrent Drought Outlook Recent Changes to the OutlookRecent Changes to the Outlook Some ideas for future OutlooksSome ideas for future Outlooks

Recent U.S. Drought Monitor

Year-to-Date Drought Change: Wetness Plains Book-ended by Droughts West and East

October vs April Drought

Winter Percent of Normal Precipitation Downtown Los Angeles had driest “rain season” since at least 1877: 3.21 in., 21% of normal.

Western Snowpack 2007 vs 2006

Streamflow Forecasts 2007 vs 2006

Spring-Summer Changes

Fires Spread Dramatically Across the West in July

Mid-Atlantic Drought Worsens Sep-Oct 5 Maryland wells at Record lows mid-October Charles County well sets record Record 34 days without measurable rain at DCA thru October 18, 2007

Southeast Virginia: Little Creek Reservoir near Newport News October 15, 2007 Photo by Don Aspinall

Historical Drought in Alabama lwf.ncdc.noaa.gov/img/climate/research/2007/sep/Reg001Dv00_palm06_ _pg.gif One of 2 worst droughts past 50 years

Georgia Drought

Lake Lanier October, day supply left for Atlanta?

Tennessee Drought Worst in over 50 yrs.

Cherokee Lake in E. Tennessee Sep 12, 2007 Photo by Brian Boyd

North Carolina Drought 2 nd worst in over 50 years Driest May-Sep

Kentucky Drought 2 nd worst in over 50 yrs

Rankings

Lake Okeechobee Drops to New Lows Levels remain ~ 5 feet lower than normal in October 2007

Selected Drought Impacts to Crops in the Southeast Corn Yield vs 2006Corn Yield vs 2006 Virginia -33%Virginia -33% Maryland -40%Maryland -40% North Carolina -33%North Carolina -33% Tennessee -15%Tennessee -15% Kentucky -15%Kentucky -15% Alabama +1%Alabama +1% Georgia +5%Georgia +5% Peanut Yields vs 2006Peanut Yields vs 2006 Virginia -37%Virginia -37% North Carolina -25%North Carolina -25% Georgia +6%Georgia +6%

The Seasonal Drought Outlooks

Last Night’s 5-Day QPF

One Week Soil Moisture Forecast

Recent Changes Began twice/month schedule (1 st and 3 rd Thursday)Began twice/month schedule (1 st and 3 rd Thursday) Expanding CPC authorsExpanding CPC authors Changed wording of headings (“Tendency”, valid dates)Changed wording of headings (“Tendency”, valid dates)

Drought Verification Jul-Sep 2007

Improvement over Persistence Percent of Grid Points Correct vs a Forecast Based on Persisting Droughts Long-term mean = 13%

Two Path Approach to Improving Drought Forecasts at CPC Continue to produce and refine seasonal drought outlooks for the general publicContinue to produce and refine seasonal drought outlooks for the general public a. Consider adding monthly forecasts b. Consider adding probability information to map Develop objective seasonal probability forecasts for drought (guidance useful for an array of users)Develop objective seasonal probability forecasts for drought (guidance useful for an array of users) a. Drought probabilities (soil moisture, runoff, drought indices) at some point in the future b. Probabilities for change c. Consider NIDIS goals d. Climate Test Bed products to contribute

One Prototype Suggestion of a Probabilistic Forecast

University of Washington Forecasts

“Prediction is very difficult, especially about the future” Niels Bohr, Danish physicist (not Yogi Berra)