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Hydro-climate Review for the water Hydro-climate Review for the water year 2008year 2008

Kingtse C. Mo and Wanru WuKingtse C. Mo and Wanru Wu Climate Prediction Center/NCEP/NWSClimate Prediction Center/NCEP/NWS High lights

Drought: Southern Texas, & California, Southeast

Floods : Mississippi River basin

A good North American monsoon.

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Drought Briefing Drought Briefing http://www.cpc.ncep.noaa.gov/products/Drought

Drought briefing on the second Thursday of the Drought briefing on the second Thursday of the month at 11AM eastern time month at 11AM eastern time

Monitor atmospheric and hydrological conditions Monitor atmospheric and hydrological conditions in support of operational Drought Monitor and in support of operational Drought Monitor and Drought OutlookDrought Outlook Provide users timely information and analysis on Provide users timely information and analysis on

drought. drought. Bring drought forecasters and products generators Bring drought forecasters and products generators

together for discussion. together for discussion. Contact person: Kingtse.mo@noaa.govContact person: Kingtse.mo@noaa.gov

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objective monitoring many faces of droughtobjective monitoring many faces of drought Meteorological droughtMeteorological drought: Precipitation deficit. : Precipitation deficit. Index: Standardized Precipitation Index (SPI)Index: Standardized Precipitation Index (SPI) Hydrological droughtHydrological drought: Stream flow or runoff : Stream flow or runoff

deficitdeficit Index: Standardized runoff index (SRI)Index: Standardized runoff index (SRI) Agricultural droughtAgricultural drought: Total soil water storage : Total soil water storage

deficit deficit Index: soil moisture anomaly percentilesIndex: soil moisture anomaly percentiles

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Drought Briefing Drought Briefing http://www.cpc.ncep.noaa.gov/products/Drought

Surface conditions including Surface conditions including soil conditionssoil conditions, , E, PE, P– from the – from the

ensemble NLDAS (EMC) and the ensemble NLDAS (EMC) and the University of Washington. University of Washington.

Atmospheric conditions and Atmospheric conditions and budget terms : NARRbudget terms : NARR

Forecasts: Forecasts: U. Washington (ESP)U. Washington (ESP)

Princeton U (downscaling from Princeton U (downscaling from the CFS using VIC)the CFS using VIC)

NSIPP (from NSIPP model)NSIPP (from NSIPP model)

Dennis Lettenmaier’s presentation on Wed.

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Precip anomaliesPrecip anomalies

Dryness: California, Southern Texas, Southeast

Wetness: Ohio Valley (3 seasons) and central United States, a wet NA monsoon

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Drought: local phenomenonDrought: local phenomenon

1. Heavy flooding over Iowa, Mo,& Illinois in June

2. Dryness over the Southeast & Texas and California

3. This pattern persisted from April-July

June 2008 AMJ 2008

Kansas : western Kansas : D3 drought

Eastern Kansas: Flood

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Uncertainties of SM percentiles :Jun2008

3 model ensemble;

CPC unified P analysis;

Base:1979-2006

Univ. of Washington ensemble:EMC/NCEP

6 model ensemble;

P from NCDC stations

1920-2003

88

6-month SPI (SPI6)6-month SPI (SPI6)

99

Ensemble sm percentiles (EMC)Ensemble sm percentiles (EMC)

1010

Stream flow anomalies (USGS)Stream flow anomalies (USGS)Jan

Apr

Jul

Oct

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ENSO (SST)Cold ENSO OND 2007 through JFM 2008 -> Neutral in JAS

Tropical convection:Suppressed convection through summer

180

Jul2008

1212

Drought:California

Southern Texas

Southeast

Floods:Mississippi River Basin

Northern Plains

P

SPI 6

SM

SRI6

1313

California DroughtCalifornia Drought

Month

P

SM

Strong seasonal cycle

Rain: Nov-March

Below normal P for winter

dry SM

SM: ensemble NLDAS (EMC)

Path to droughtOND 2007 –JFM 2008: Below normal rainfall due to cold ENSOSM below normalNo rainfall after MarchSM depreciated even more

Cold ENSO below normal rainfall

Climatology

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Impact of cold ENSO: Impact of cold ENSO: Dry Southern TexasDry Southern TexasSoutheast, CaliforniaSoutheast, California

PSPI6

Texas, Southern Plains:

Cold ENSO drought

Southeast:

Cold ENSO Drought in winter

Relieve in summer

Mo and Schemm 2008

Composites

1515

A very wet monsoonA very wet monsoon

Over the Southwest, this was the 6th wettest season since 1948.

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June 2008 Mississippi FloodJune 2008 Mississippi FloodStrong

GPLLJ

IASLLJ

1717

Path to floodsPath to floods

Box: (30-50N,100-120W)

Byerle and Paegle 2003 (JGR)

Interaction bwt U200 and mountains GPLLJ

GPLLJ

S200a Colored U200a Contoured

1818

A Possible path to floodsA Possible path to floods SSTAs in the tropical Pacific showed a diminishing SSTAs in the tropical Pacific showed a diminishing

cold ENSO event, convection was still suppressed.cold ENSO event, convection was still suppressed. Enhanced convection (rainfall) was located over the Enhanced convection (rainfall) was located over the

eastern Pacific and southern Mexicoeastern Pacific and southern Mexico The downward branch of the Hadley cell was located The downward branch of the Hadley cell was located

in the Southeastin the Southeast less P consistent with anticyclone less P consistent with anticyclone Anomalous 200 hPa Vorticity source (S200a)Anomalous 200 hPa Vorticity source (S200a)

supported U200 extended to the West Coastsupported U200 extended to the West Coast Jet interacts with the mountains Jet interacts with the mountains strong GPLLJ strong GPLLJ

more moisture more moisture more rainfall more rainfall

1919

SummarySummary RR and ensemble NLDAS were used to RR and ensemble NLDAS were used to

monitor drought/floods over the United States.monitor drought/floods over the United States. Drought briefing is given monthly to support Drought briefing is given monthly to support

drought monitor and outlookdrought monitor and outlook While all NLDAS systems are able to point to While all NLDAS systems are able to point to

areas under drought, spread is too large to areas under drought, spread is too large to determine the drought classification.determine the drought classification.

We are looking for the results from this We are looking for the results from this meeting to give us guidance.meeting to give us guidance.

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2008 hydroclimate conditions2008 hydroclimate conditions

While the SSTAs show drought ended in JAS, the While the SSTAs show drought ended in JAS, the convection pattern still showed suppressed convection pattern still showed suppressed convection over the central Pacific and enhanced convection over the central Pacific and enhanced convection over the eastern Pacific & southern convection over the eastern Pacific & southern Mexico.Mexico.

California drought: strong seasonal cycle , lack of California drought: strong seasonal cycle , lack of rain in winter 2007 and depreciated soil moisturerain in winter 2007 and depreciated soil moisture

Southeast: Drought intensified in winter, but had Southeast: Drought intensified in winter, but had some relieve in summer due to hurricanes.some relieve in summer due to hurricanes.

Southern Texas: Cold ENSOSouthern Texas: Cold ENSO drought drought

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Evolution of Evolution of SSTAsSSTAs

Cold ENSO lasted from OND 2007 through JFM 2008 and then diminished.

In JAS, the cold event ended and the ENSO neutral conditions were observed in the tropical Pacific.

The North Atlantic SSTAs are still in the decadal positive phase of the AMO

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Southeast droughtSoutheast drought

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