U.S Drought Highlights Since October 2006 Douglas Le Comte NOAA/CPC 32nd Annual Climate Diagnostics...
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Transcript of U.S Drought Highlights Since October 2006 Douglas Le Comte NOAA/CPC 32nd Annual Climate Diagnostics...
U.S Drought Highlights Since U.S Drought Highlights Since October 2006October 2006
Douglas Le ComteDouglas Le Comte
NOAA/CPCNOAA/CPC
32nd Annual Climate Diagnostics and Prediction Workshop32nd Annual Climate Diagnostics and Prediction Workshop
October 22-26, 2007October 22-26, 2007
Morristown,Morristown,TN, Sep. 12,TN, Sep. 12,20072007
waterban_2web.movGeorgia gets toughGeorgia gets toughon water use!on water use!
OutlineOutline
• 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 MonitorRecent U.S. Drought Monitor
Year-to-Date Drought Change:Year-to-Date Drought Change: Wetness Plains Book-ended by Droughts West and Wetness Plains Book-ended by Droughts West and
EastEast
October vs April DroughtOctober vs April Drought
Winter Percent of Normal Winter Percent of Normal PrecipitationPrecipitation
Downtown Los Angeles had driest“rain season” since at least1877: 3.21 in., 21% of normal.
Western Snowpack 2007 vs 2006Western Snowpack 2007 vs 2006
Streamflow Forecasts 2007 vs 2006Streamflow Forecasts 2007 vs 2006
Spring-Summer ChangesSpring-Summer Changes
Fires Spread Dramatically Across Fires Spread Dramatically Across the West in Julythe West in July
Mid-Atlantic Drought Worsens Mid-Atlantic Drought Worsens Sep-OctSep-Oct
5 Maryland wells at5 Maryland wells atRecord lows mid-OctoberRecord lows mid-October
Charles CountyCharles Countywell sets recordwell sets record
Record 34 daysRecord 34 dayswithout measurablewithout measurablerain at DCA thrurain at DCA thruOctober 18, 2007October 18, 2007
Southeast Virginia:Southeast Virginia: Little Creek Reservoir Little Creek Reservoir
near Newport Newsnear Newport NewsOctober 15, 2007October 15, 2007
Photo byPhoto byDon AspinallDon Aspinall
Historical Drought in AlabamaHistorical Drought in Alabama
http://http://lwf.ncdc.noaa.gov/img/climate/research/2007/sep/Reg001Dv00_palm06_01000907_pg.giflwf.ncdc.noaa.gov/img/climate/research/2007/sep/Reg001Dv00_palm06_01000907_pg.gif
One of 2 worstOne of 2 worstdroughts past droughts past 50 years50 years
Georgia DroughtGeorgia Drought
Lake LanierLake LanierOctober, 2007October, 2007
90-day supply 90-day supply left for Atlanta?left for Atlanta?
Tennessee DroughtTennessee Drought
Worst inWorst inover 50 yrs.over 50 yrs.
Cherokee Lake in E. TennesseeCherokee Lake in E. Tennessee Sep 12, 2007 Sep 12, 2007
Photo byPhoto byBrian BoydBrian Boyd
North Carolina DroughtNorth Carolina Drought
22ndnd worst in worst inover 50 yearsover 50 years
Driest May-SepDriest May-Sep
Kentucky DroughtKentucky Drought
22ndnd worst worstin over 50 yrsin over 50 yrs
RankingsRankings
http://lwf.ncdc.noaa.gov/oa/climate/research/2007/sep/national.htmlhttp://lwf.ncdc.noaa.gov/oa/climate/research/2007/sep/national.html
Lake Okeechobee Drops to New LowsLake Okeechobee Drops to New Lows
Levels remainLevels remain~ 5 feet lower ~ 5 feet lower than normal inthan normal inOctober 2007October 2007
Selected Drought Impacts to Crops in the Selected Drought Impacts to Crops in the SoutheastSoutheast
• 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 OutlooksThe Seasonal Drought Outlooks
Last Night’s 5-Day QPFLast Night’s 5-Day QPF
One Week Soil Moisture ForecastOne Week Soil Moisture Forecast
Recent ChangesRecent Changes
• Began twice/month schedule (1Began twice/month schedule (1stst and 3 and 3rdrd Thursday)Thursday)
• Expanding CPC authorsExpanding CPC authors
• Changed wording of headings Changed wording of headings (“Tendency”, valid dates)(“Tendency”, valid dates)
Drought Verification Drought Verification Jul-Sep 2007Jul-Sep 2007
Improvement over PersistenceImprovement over PersistencePercent of Grid Points Correct vs a Forecast Based on Persisting DroughtsPercent of Grid Points Correct vs a Forecast Based on Persisting Droughts
Drought Outlook -- Forecast minus Persistence
-20
-10
0
10
20
30
40
50
60
Jul '03 Nov'03
Mar'04
Jul '04 Nov'04
Mar'05
Jul '05 Nov'05
Mar'06
Jul '06 Nov'06
Date of Forecast
Fo
reca
st L
ess
Per
sist
ence
Skill MEAN Linear (Skill)
Long-term mean = 13%Long-term mean = 13%
Two Path Approach to Improving Two Path Approach to Improving Drought Forecasts at CPCDrought Forecasts at CPC
• Continue to produce and refine seasonal drought outlooks for the Continue to produce and refine seasonal drought outlooks for the general publicgeneral public
a. Consider adding monthly forecastsa. Consider adding monthly forecasts
b. Consider adding probability information to mapb. Consider adding probability information to map
• Develop Develop objective seasonal probabilityobjective seasonal probability forecasts for drought forecasts for drought (guidance useful for an array of users)(guidance useful for an array of users)
a. Drought probabilities (soil moisture, runoff, drought a. Drought probabilities (soil moisture, runoff, drought indices) at some point in the futureindices) at some point in the future
b. Probabilities for changeb. Probabilities for change
c. Consider NIDIS goalsc. Consider NIDIS goals
d. Climate Test Bed products to contribute d. Climate Test Bed products to contribute
One Prototype Suggestion of a One Prototype Suggestion of a Probabilistic ForecastProbabilistic Forecast
University of Washington ForecastsUniversity of Washington Forecasts
http://www.hydro.washington.edu/forecast/monitor/outlook/index.shtml
““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)