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North American Drought BriefingFor Jan & Nov 2007 to Jan 2008

Climate Prediction Center/NCEP/NOAAFebruary 14, 2008

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

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Partners & ContributorsCPC: Kingtse Mo, Wanru Wu, Muthuvel Chelliah, Wesley Ebisuzaki, Yun Fan, Huug van den Dool, Wei Shi

EMC: NLDAS Team: Ken Mitchell, Youlong Xia, Jesse Meng, Helin Wei

EMC: NAEFS Team: Zoltan Toth, Yuejian Zhu

NASA/GSFC: Brian Cosgrove, Chuck Alonge

Princeton Univ.: Eric Wood, Lifeng Luo, Justin Scheffield

Univ. of Washington: Andy Wood, Dennis Lettenmaier

Web Masters: Viviane Silva, Joe Harrison

Project Funded by NOAA CPPA

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P from Nov 2007-Jan 2008

California: Strong intraseasonal oscillations

Southeast: Dec had some rain along the Gulf coast. No rain in Jan. Drought continues

Texas and Southern Plains: Drought is developing

Colorado: Rain in both Dec and Jan

Nov 2007-Jan2008

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SPI3:

•The Northern central US is getting dryer

•Texas: drought started to develop.

•California had some rain ( so less dry) in comparison with last month.

In the long term SPI6 or higher Severe drought still exists in the Southeast including parts of Florida.Drought D0:SPI < -0.8

Moderate drought D1: -0.9 to -1.2

Severe drought D2: -1.3 to -1.5

Extreme drought D3: -1.6 to -1.9

Exceptional drought D4: SPI< -2 Ref: Svoboda et al. (2002)

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Soil moisture percentiles NASA (29-yr clim) Cosgrove and Alonge

Southeast: dry

Pacific Northwest: Wet

Texas: getting dryer

Ohio, northern Plains : wet

Ensemble SM mean(10-yr clim)

Total SM percentile from RR (29-yr clim)

MosaicNoah

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SM Percentiles at Different Levels Based on RR

Texas and Dakota : dryness from 10cm to 1m, but into deep soil yet.

Southeast: SM dryness to the deep level

Drought D0:SM < 20% Moderate drought D1: 10-20%Severe drought D2: 5-10%Extreme drought D3: 2-5%Exceptional drought D4: <2%

Ref: Svoboda et al. (2002)

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Monthly Streamflow Conditions

Southwest and mid-Atlantic states: dry

Northeast and Ohio Valley: wet

Southern Plains: getting dryer

California: coast normal & inland dry

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SRI3 and SRI 6 U. Washington – Andy Wood

Standardized runoff index SRI

SRI3

SRI6

In comparison with the SPIs, they all suggest:

1. Southeast: severe drought

2. Texas: drought started to develop (only appears in spi3 and sri3, not spi6 or sri6 longer)

3. SRI shows California drought.

1955-2005

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Snow Water Equivalent (mm/day)

NLDAS does not agree over the western mountain region: RR, Noah, VIC are positive and mosaic is negative

All shows negative anomalies over the Northeastern region

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Weekly precipitation

2-8 Feb 2008

More precipitation over the Pacific Northwest and Ohio Valley, the Southeast is still very dry

Weekly soil moisture anom ensemble

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Hot Spots

• California: Rainfall does not entirely influenced by the cold ENSO signal because of the strong MJO.

• Southeast drought: any relief in sight?

• Texas and southern Plains: Will cold ENSO make it worse?

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MJO and California Rainfall

150E Cal PNW

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SSTs for Drought over the Southern Plains and the Southeast

Pickup drought events based on SM percentiles over RFC10 (S-Plains) and RFC12 (Southeast) respectively

Make the composites of SSTA based on events

Cold SSTAs in the central Pac;

Warm SSTAs in the Atlantic and the N-Pac

Data source (SM) VIC 1915-2006 Andy wood

SST ersst: 1915-2006

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SSTAs for Jan 2008

The ENSO forecasts indicate that the cold ENSO event will continue for the next 3 months.

The Atlantic SSTAs are decreasing (slowly since Nov).

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Because the land-atmosphere coupling is strong over the Southern Plains, the drought events last longer in comparison with droughts over the SE .

Using the VIC data (from 1915 on), we identify events

1917 May lasted 20 mos

1952 Jun Lasted 36 mos

1963 Apr lasted 16 mos

Most recent one was 2005 lasted 9 mos

Regional SM percentile Time Series

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Regional total Soil moisture percentiles

Time series

Overall, the duration for droughts in RFC12 (Southeast) is shorter than droughts in the RFC10 area.

The longest drought occurred in 1954. It lasted for 14 months

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Cold ENSO signalNAEFS Week1 and Week2 Fcsts

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CFS Downscaling Princeton UJan 2008

Feb 2008

Mar2008

Forecasts started from Jan 2008

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ESP Forecasts ENSO Based IC 20080203

1 month lead

2 month lead

3 month lead

Total SM Percentile Forecasts

University of Washington - Andy Wood

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Runoff Percentiles Forecasts ICs 200802101 month

2 months

3 months

University of Washington - Andy Wood

Southeast and Texas dryness continue for 1-2 months

The upper Missouri basin will get dryer

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Summary• Southeast: Drought is likely to continue.• California: The MJO has strong influence on

rainfall. The convection related to the MJO does not in favor of rainfall in the next 15 days or so.

• Pacific Northwest, the Northeast and the Ohio Valley: likely to be wet.

• Drought is developing over the Southern Plains.• There is indication of dryness in south and north

Dakota and part of Minnesota. • Areas needed to be monitored carefully:

California and Southeast, Texas, Dakotas

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Thanks for New Products

• Brian Cosgrove and Chuck Alonge:

Soil moisture percentiles based on 20+ year climatology (1979 on) from Mosaic and Noah

• Andy Wood: SRI plots for runoff and SRI forecasts

• Happy Valentine’s day!!!