U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics...

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U.S Drought Highlights Since U.S Drought Highlights Since October 2004 October 2004 Douglas Le Comte Douglas Le Comte NOAA/CPC NOAA/CPC 30 30 th th Annual Climate Diagnostics and Prediction Annual Climate Diagnostics and Prediction Workshop Workshop October 24-28, 2005 October 24-28, 2005

Transcript of U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics...

Page 1: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

U.S Drought Highlights Since U.S Drought Highlights Since October 2004October 2004

Douglas Le ComteDouglas Le Comte

NOAA/CPCNOAA/CPC

3030thth Annual Climate Diagnostics and Prediction Workshop Annual Climate Diagnostics and Prediction Workshop

October 24-28, 2005October 24-28, 2005

Page 2: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

OutlineOutline

• Drought HighlightsDrought Highlights—Southwest Alleviation, —Southwest Alleviation,

Northwest Development, and Midwest Summer DevelopmentNorthwest Development, and Midwest Summer Development

• Drought ForecastsDrought Forecasts—How are we doing?—How are we doing?

Page 3: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

What A Difference A Season Made in the What A Difference A Season Made in the West!West!

Page 4: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

October vs April DroughtOctober vs April Drought

Page 5: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

Water Year PrecipitationWater Year Precipitation

Page 6: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

Snow Water Content April 2005Snow Water Content April 2005

Page 7: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

Impressive Snowpack on Snowbird Impressive Snowpack on Snowbird November 7, 2004November 7, 2004

A pretty good omen that the 2004-05 snow seasonwould be extraordinary!

Page 8: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

Southwest U.S. April-October PMDI Change vs Nino 3.4 SSTA

y = 0.9125x - 0.1103

R2 = 0.1269

-6.00

-5.00

-4.00

-3.00

-2.00

-1.00

0.00

1.00

2.00

3.00

4.00

5.00

6.00

-2.5 -2

-1.5 -1

-0.5 0

0.5 1

1.5 2

2.5 3

Nino 3.4 SSTA deg C

PM

DI C

han

ge

Nino 3.4 SST Anom Dec-Feb Linear (Nino 3.4 SST Anom Dec-Feb)

WETTER

WARMER SSTs

Although El Nino’s are generallyassociated with improved droughtconditions in the U.S. Southwest,this is by no means assured. The bestodds for improvement come withstronger events (SST anomaliesover +1.5 deg. C).

EL NINO’S and SOUTHWESTERN DROUGHTEL NINO’S and SOUTHWESTERN DROUGHT

Expected rangeof SSTs

Page 9: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

Streamflow Forecasts April 1, 2005Streamflow Forecasts April 1, 2005

Page 10: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

Spring-Summer ChangesSpring-Summer Changes

Page 11: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

April vs July 2005April vs July 2005

Page 12: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

Changes to October 4, 2005Changes to October 4, 2005

Page 13: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

August vs October 2005August vs October 2005

Page 14: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

October 4 vs October 11 2005October 4 vs October 11 2005

Page 15: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

The Seasonal Drought OutlooksThe Seasonal Drought Outlooks

                                                                                                                  

                                                                                

Page 16: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

Selected Drought Outlook ToolsSelected Drought Outlook Tools

• 2-Week Soil Moisture2-Week Soil Moisture

• Seasonal Constructed Analog Soil ForecastsSeasonal Constructed Analog Soil Forecasts

• NCDC Palmer Drought Amelioration Probability MapsNCDC Palmer Drought Amelioration Probability Maps

Page 17: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

CPC 2-Wk Soil Moisture ForecastCPC 2-Wk Soil Moisture Forecasthttp://www.cpc.ncep.noaa.gov/soilmst/cas.shtml

                                                                                                              

                                                                                        

Page 18: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

Constructed Analog Soil Moisture USAConstructed Analog Soil Moisture USA

http://www.cpc.ncep.noaa.gov/soilmst/cas.shtml

Observed

Forecast

Page 19: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

NCDC Drought Amelioration ProbabilitiesNCDC Drought Amelioration Probabilities

Page 20: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

How Are We Doing?How Are We Doing?

Page 21: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

How Did We Do With the Western Drought?How Did We Do With the Western Drought?

Too cautiousin September!

Finally gotit right in Dec!

Page 22: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

Time Series of Verification ScoresTime Series of Verification Scores

Drought Outlook Verification Score

0

10

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50

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70

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100

Jul'03

Sep'03

Nov'03

Jan'04

Mar'04

May'04

Jul'04

Sep'04

Nov'04

Jan'05

Mar'05

Date of Forecast

Pe

rce

nt

of

Are

a C

orr

ec

t

Percent of Area Correct Persistence Score MEAN SCORE MEAN Persistence

Mean Pct Correct 59%Mean Persistence Score 45%

Page 23: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

Selected Future ImprovementsSelected Future Improvements

• Better seasonal temp/precip forecasts thanks to Better seasonal temp/precip forecasts thanks to new consolidation toolnew consolidation tool

• Better seasonal soil moisture forecasts from Better seasonal soil moisture forecasts from NLDAS projects (Univ. of WA, Princeton, NCEP)NLDAS projects (Univ. of WA, Princeton, NCEP)

• Research leading to improved understanding of Research leading to improved understanding of the underlying causes of drought (e.g., air-sea and the underlying causes of drought (e.g., air-sea and ground-air interactions)ground-air interactions)

Page 24: U.S Drought Highlights Since October 2004 Douglas Le Comte NOAA/CPC 30 th Annual Climate Diagnostics and Prediction Workshop October 24-28, 2005.

Parting WisdomParting Wisdom

• ““If you’re going to predict, predict often. If you’re going to predict, predict often. As long as you keep updating your As long as you keep updating your prediction, people forget your last prediction, people forget your last prediction.”prediction.”

Milton FriedmanMilton Friedman