Current Drought Conditions Winter

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Current Drought ConditionsWinter Spring
Outlooks25 October 2007

• David Emory Stooksbury, Ph.D.
• State Climatologist and Associate Professor
• Engineering and Atmospheric Sciences
• The University of Georgia
• 706-583-0156
• stooks_at_engr.uga.edu

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Measuring Drought

• Rainfall
• Water Year (Since 1 October)
• 12 Months
• 6 Months
• 3 Months
• 1 Month
• Soil Moisture
• Stream Flows
• Reservoir Levels
• Groundwater Levels
• Indices

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Monitoring Drought www.georgiaweather.net
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Percent of Normal Precipitation
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Percent of Normal Precipitation
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Percent of Normal Precipitation
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Percent of Normal Precipitation
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Percent of Normal Precipitation
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Cumulative departures from normal
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Soil Moisture
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Soil Moisture - Top
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Soil Moisture - Deep
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Stream Flows
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USGC
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USGC
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USGC
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USGC
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USGC
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USGC
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USGC
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USGC
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Reservoir Levels
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Reservoir Levels
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Reservoir Levels
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Reservoir Levels
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Reservoir Levels
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Reservoir Levels
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Reservoir Levels

• Hartwell 9.5 feet below guidance
• Clarks Hill 10 feet below guidance

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Map of KBDI
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KBDI Deviation from Normal
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Classification of DroughtsMultiple Indices at

• Abnormally Dry 20th Percentile (1 in 5 years)
• Mild Drought 15th Percentile (1 in 6.7 years)
• Moderate Drought 10th Percentile (1 in 10
  years)
• Severe Drought - 5th Percentile (1 in 20 years)
• Extreme Drought 2nd Percentile (1 in 50 years)
• Exceptional 1st Percentile (1 in 100 years)

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U.S. Drought Monitor
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U.S. Drought Monitor
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Climate Outlook

• Little to no skill during the summer

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Climate Outlook

• Little to no skill during the summer
• WE HAVE SKILL IN THE COOL SEASON

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Forecasting

• Equatorial Pacific Sea Surface Temperature
• 0.5 oC above average or more El Nino
• - 0.5 oC below average or more La Nina
• Between -0.5 and 0.5 oC of average Neutral
• Temperature and Precipitation

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Weak, Moderate Strong La Nina Impacts on
Winter Precipitation
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Weak, Moderate Strong La Nina Impacts on
Spring Precipitation
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SST Outlook NCEP CFS Forecast Issued 15 October
2007
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IRI SST Outlook Issued October 2007
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December 2007 February 2008CPC Temperature
Outlook Made September 2007
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December 2007 February 2008CPC Temperature
Outlook Made October 2007
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December 2007 February 2008CPC Precipitation
Outlook Made September 2007
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December 2007 February 2008CPC Precipitation
Outlook Made October 2007
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March May 2008CPC Temperature Outlook Made
September 2007
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March May 2008CPC Temperature Outlook Made
October 2007
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March May 2008CPC Precipitation Outlook Made
September 2007
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March May 2008CPC Precipitation Outlook Made
October 2007
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IRI Multi-Model Probability Forecast for
Temperature
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IRI Multi-Model Probability Forecast for
Precipitation
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IRI Multi-Model Probability Forecast for
Temperature
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IRI Multi-Model Probability Forecast for
Precipitation
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Southeast Climate Consortium

• University of Georgia
• University of Alabama Huntsville
• Florida State University
• Auburn University
• University of Florida
• University of Miami
• Climate impacts on agricultural and forestry
  resources, water resources, and coastal resources
• Regional Climate Forecasts

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Southeast Climate ConsortiumsWinter 2007-08

• The warmer temperatures will impact winter crops
  and fruit production, resulting in less chill
  accumulation over the course of the winter
  season.
• Warmer temperatures will also mean greater
  evaporation rates. Due to the jet stream
  configuration described above, severe or damaging
  freezes are less likely during La Niña than in
  neutral years.
• However, the risk of early or late season freezes
  (like in April of 2007) does not seem to be
  affected by the Pacific Ocean.

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Southeast Climate ConsortiumsWinter 2007-08

• The shift towards drier than normal conditions
  becomes much more pronounced in Florida and
  coastal Georgia and Alabama as fall progresses
  into winter, resulting in much higher confidence
  in a forecast of dry conditions in these areas.
• La Niña does not impact central and northern
  Georgia and Alabama nearly as much, so there is
  much more uncertainty in the precipitation
  forecast for these areas and near normal is more
  likely, unless this La Niña grows into a strong
  event.

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Southeast Climate ConsortiumsWinter 2007-08

• Even with near normal rainfall, drought
  conditions are likely to persist in northern
  Georgia and Alabama, but some lessening of the
  severity is possible with the winter rainfall.

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Summary

• Extreme to Exceptional Drought
• North Georgia
• West Georgia

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Summary

• Extreme to Exceptional Drought
• North Georgia
• West Georgia
• Little hope of major recovery through at least
  the spring of 2008
• Good probability that southeast Georgia could
  experience drought conditions by spring

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Summary

• Extreme to Exceptional Drought
• North Georgia
• West Georgia
• Little hope of major recovery through at least
  the spring of 2008
• Good probability that southeast Georgia could
  experience drought conditions by spring
• Major Concern We could muddle through the winter
  and spring but would have virtually no reserve
  for summer 2008.

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Drought Updates

• State Drought Page
• http// www.georgiadrought.org
• UGAs Automated Weather Stations
• http// www.georgiaweather.net
• Southeast Climate Consortium
• http//secc.coaps.fsu.edu/
• AgClimate
• http// www.agclimate.org