# Presentation: 912509

## North American Drought BriefingFor Jan & Nov 2007 to Jan 2008

- Climate Prediction Center/NCEP/NOAA
- February 14, 2008
- _[http://](http://www.cpc.ncep.noaa.gov/products/Drought)__[www.cpc.ncep.noaa.gov](http://www.cpc.ncep.noaa.gov/products/Drought)__[/products/Drought](http://www.cpc.ncep.noaa.gov/products/Drought)_

## Partners & Contributors

**CPC:** 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**

## 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

## SPI3:

**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)**

## 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)

- Mosaic

- Noah

## 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)**

## Monthly Streamflow Conditions

- Southwest and mid-Atlantic states: dry
- Northeast and Ohio Valley: wet
- Southern Plains: getting dryer
- California: coast normal & inland dry

## SRI3 and SRI 6 U. Washington – Andy Wood

- Standardized runoff index SRI

- SRI3

- SRI6

- In comparison with the SPIs, they all suggest:
- Southeast: severe drought
- Texas: drought started to develop (only appears in spi3 and sri3, not spi6 or sri6 longer)
- SRI shows California drought.

- 1955-2005

## 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

## Weekly precipitation 

- 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

## 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?

## MJO and California Rainfall 

- 150E

- Cal

- PNW

## 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

## 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).

## Regional SM percentile Time Series

- 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 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

## NAEFS Week1 and Week2 Fcsts

- Cold ENSO signal

## CFS Downscaling Princeton U

- Jan 2008

- Feb 2008

- Mar2008

- Forecasts started from Jan 2008

## ESP Forecasts ENSO Based IC 20080203

- 1 month lead

- 2 month lead

- 3 month lead

- Total SM Percentile Forecasts

- University of Washington - Andy Wood

## Runoff Percentiles Forecasts ICs 20080210

- 1 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

## 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

## 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!!!