# Presentation: 914084

## North American Drought BriefingFor Dec & OND 2007

- Climate Prediction Center/NCEP/NOAA
- January 10, 2007
- _[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 anom for OND 2007

- Dec 2007 was overall a wet month in contrast to Nov 2007.
- P(dec) anomaly map shows the current cold ENSO signal:  positive anomalies over the Pacific Northwest and the Ohio Valley and dryness over California.
-   In addition, it shows positive P anom over Colorado and Arizona

## Qflux anom (vector, qu are colored)

- In December
- 1. The North American jet shifted northward so there were more storms over the North central and the Northeast.
- 2. There were more moisture fluxes transported into Colorado, the Pacific northwest.

- NOV 2007

- DEC 2007

## SST anom

- In the tropical Pacific:
- Cold ENSO continued
- In the Atlantic,
- SSTAs were slightly weaken

## Ensemble soil moisture ensemble anom

- SM top 10cm

- SM top 40cm

- SM top 1m

- SM total

- December 2007

- OND 2007 SM total

- The total SM (most from the deep soil layers) still had strong deficit over the Southeast. Because of the cold ENSO, California showed SM deficit.

## Total soil moisture change Dec -Nov

- All NLDAS systems give a consistent picture of depreciation of soil moisture over the Southeast and  northern California
- SM increased over the Ohio Valley and Pacific Northwest

## SPI for Southeast through Dec 2007

- For the SE ,large SM (P) deficit is unlikely to recover due to few P events.

- The past long drought events:
- 1954—16 months
- 1984– 10  months
- 1999---- 9 month
- 2001----9 months
- Most drought started in winter and ended in summer

## SPI for California RFC through Dec 2007

- The deficit is not as large as
- the Southeast. Will strong MJO bring California out of drought?

- Past strong drought events
- Jan 1929 - Nov1931– 35 months
- Sep 1932 –Sep 1934-  25months
- Nov 1958- Oct 1960 24 months
- Jan 2001- Oct 2002 22 months

## USGS streamflow for Dec

- Streamflow deficit over the Southeast, California and the West mountain regions

## Ensemble Snow water equivalent mm/day

## OLRA for Dec and 1st week in Jan

- For Dec, it was a typical cold NSO pattern
- For the first week of Jan, heavy rainfall over the west coast was modulated by the MJO.

## Experimental GFS MJO OLR Forecast

_**Experimental GFS MJO OLR Forecast**_

**The GFS forecasts a moderate a MJO signal with slight eastward propagation during the period – mainly during week 1. **
**Wet conditions are expected for the Maritime continent throughout much of the period with enhanced convection shifting slowly into the western Pacific Ocean. **
**Suppressed convection is forecast for Africa and the Indian Ocean. **

- From : M. L’Heureux

- California rainfall
- (blue) is modulated by the MJO

- Jan 4-8

- Jan 9-13

- Jan 14-18

## P (31 Dec 2007-6Jan2008)

- There were heavy rain events  over the west coast during the first week of  Jan. There were large P anomalies over California and Colorado, but the Southeast was still dry.

## SM total anomaly (31Dec-6Jan 2008)

- These rainfall anomalies over California
- were not enough to bring it out of drought.

## WEEK1 (9-15Jan)

- WEEK2 (16-22Jan)

- P anom

- P spread

- SM anom

- SM spread

- GFS NAEF FCSTs

- Pacific Northwest will have a break of rain in week 2.
- Southeast gets some rain in week1, but drought persists
- California is dry so drought conditions are likely to continue

## ENSO composite for P

## CFS P forecastsa typical cold ENSO signal

## U Washingtonfrom Andy wood

- SM Fcst for JFM 2008

- Runoff Fcst for JFM 2008

- From Princeton University
- Lifeng Luo
- IC: 200711
- CFS downscaling total SM

- Jan

- Feb

- Mar

## Summary

- Southeast : Drought is likely to continue
- California: Strong MJO events brought rain in the first week of January, but these rainfall anomalies were not strong enough to over come the SM deficit. The week1 and week2 fcsts all indicate no rain so  drought may continue.
- Pacific Northwest, the Northeast and the Ohio Valley: likely to have more storms and strong rainfall events
- Areas needed to be monitored carefully: California and Southeast