# Presentation: 188314

## North American Drought Briefing:Monitoring & Forecasts

- Climate Prediction Center/NCEP/NOAA
- June 12, 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, Randy Koster
**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  CPO/CPPA** **& NASA**

## Outline

- 1. Drought Monitoring:
-     i)  P (Accumulation & Anomaly)
-     ii) Indices (SPI, SRI)
-     iii) Percentiles (Soil Moisture, Streamflow)
-     iv) Means/Anomalies (GVF, SWE, Ts)
- 2. Drought Forecasts:
-     GFS, ESP, CFS Downscaling, ENSO Condition
- 3. Summary

## 1. Drought Monitoring

- _Drought Condition in May:_
- Southeast: persisted
- California: developed
- North Dakota: intensified
- Southern Plains: persisted, a little improvement in Southern Texas

- _(a) Valid June 3, 2008_

- _(b) Valid April 29, 2008_

## CPC Precipitation Monitoring  

_**In May:**_
- Above normal rainfall over central U.S.
- Below normal over SE, Southern Plains, North Dakota

_**In MAM:**_
- A three-cell pattern:
- Above normal rainfall over central U.S.
- Below normal rainfall over Southeast and Southwest

## Qflux Anomaly for May 2008

- Strong GPLLJ  heavy rainfall and storms over the Central U.S.
- No moisture transport into the Southeast  dryness

- colored contour - qv
- arrows - (qu,qv) vectors

## Break

**In May 2008:**
- The GPLLJ was very strong.
- There were many heavy rainfall episodes causing floods and severe weather over the Central U.S.

- Correspondence between the GPLLJ and rainfall episodes

## Standardized Precipitation Index

- _[http://www.cpc.ncep.noaa.gov/products/Drought/Drought_index/Drought_index.shtml](http://www.cpc.ncep.noaa.gov/products/Drought/Drought_index/Drought_index.shtml)_

**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**

**(Data: CPC grided P 1950-present)**

- In past 3 months drought continuously developed over California

## Standardized Runoff Index 

- _[http://](http://www.hydro.washington.edu/forecast/monitor/indices)__[www.hydro.washington.edu](http://www.hydro.washington.edu/forecast/monitor/indices)__[/forecast/monitor/indices](http://www.hydro.washington.edu/forecast/monitor/indices)_

- Long lasting dryness:
- Southeast, California

**In May & MAM:**
- Dry in California, Southeast
- Wet in central US

## Multi-Model Soil Moisture Percentile for May 2008

- (a): _[http://www.cpc.ncep.noaa.gov/products/Drought/Drought_index/Drought_index.shtml](http://www.cpc.ncep.noaa.gov/products/Drought/Drought_index/Drought_index.shtml)_

- (a) NARR

- (b) & (c): _[http://ldas.gsfc.nasa.gov/drought](http://ldas.gsfc.nasa.gov/drought)_

_**Commonly dry regions:**_ Southeast, Southern Plains, North Dakota, California

## Streamflow Percentile 28-day Average obtained on 2008-06-04

- _[http://](http://waterdata.usgs.gov/waterwatch)__[waterdata.usgs.gov/waterwatch](http://waterdata.usgs.gov/waterwatch)_

- Southeast RFC

- Below normal streamflow: Southeast, Texas, North Dakota
- Above normal: central US & Northwest

- Below normal soil moisture

## Vegetation Fraction

- (a) GVF anom (04/28-05/04)

- (b) GVF anom (5/26-6/2)

- Data source: ftp://ftp.orbit.nesdis.noaa.gov/pub/corp/scsb/wguo/data/GRIB/GVF_v4.0/Initial

- The anomaly changes of the vegetation fraction reflecting the drought

- (c) GVF anomaly change in May

## Snow Water Equivalent

- (a) 2008-06-01

- http://www.nohrsc.nws.gov/nsa

- (b) 2008-05-01

- Snow melt providing water over west mountain region.
- Pacific Northwest: heavy streamflow might due to snow melt

- (c) NLDAS Ensemble and Spread for May 2008

## Surface Temperature Anomaly

- U.S. Temperature Analyses: _[http://](http://www.cpc.ncep.noaa.gov/products/tanal/accesspage.shtml)__[www.cpc.ncep.noaa.gov/products/tanal/accesspage.shtml](http://www.cpc.ncep.noaa.gov/products/tanal/accesspage.shtml)_

- _May 2008_

- _Mar-Apr-May 2008_

- Below normal temperature over the Central U.S. and above normal temperature over the Southern U.S. Nevada and northern California.

## In June 2008 ...

- _ __Heavy Rain_

- _Hot Wave_

## 2. Drought Forecasts

- Drought Tendency during June-August 2008

- Current Condition

_**Drought in the coming season:**_
- Impacts to ease: Gulf of Mexico coast, North Dakota On going: Southeast, Southern Plains           Drought to develop/persist: California, Nevada

## GFS Week1/Week2 Forecasts

- (a) P & SM forecasts corrected with NARR

- (b) SM from Leaky bucket model

- (a): http://www.cpc.ncep.noaa.gov/products/Drought/GFS_fcst.shtml (b): http://www.cpc.ncep.noaa.gov/soilmst/mrf_jh.html

## Nino3.4 forecasts from CFS (06/06/08) indicate a neutral ENSO summer 

- Nino3.4 forecasts from CFS (06/06/08) indicate a neutral ENSO summer

- JAS

- La Nina is weakening

## ESP Prediction – SM & Runoff Percentile

- _[http://](http://www.hydro.washington.edu/forecast/monitor/outlook)__[www.hydro.washington.edu](http://www.hydro.washington.edu/forecast/monitor/outlook)__[/forecast/monitor/outlook](http://www.hydro.washington.edu/forecast/monitor/outlook)_

- Initialized 20080531

- (a) SM – 1 month lead

- (b) SM – 2 month lead

- (c) Accumulative Runoff – 1 month lead

- (d) Accumulative Runoff – 2 month lead

- In June-July, wet central and dry west (California, Nevada) and Southern Plains.
- Runoff also shows dryness over Southeast

## CFS Downscaling Forecasts – SM Percentile

- _Initialized 200805_

- (a) Jun 2008

- (c) Aug 2008

- _[http://hydrology.princeton.edu/~luo/research/FORECAST/fcstvrf.php](http://hydrology.princeton.edu/~luo/research/FORECAST/fcstvrf.php)_

- (b) Jul 2008

- Delivering the similar information

## Summary

- Southeast:  Drought persisted in May. If La Nina changes to ENSO-neutral during June-July as predicted, the drought conditions are likely to continue in summer.
- Dakotas: Drought improved in South Dakota but persisted in North Dakota in May. Forecasts show some improvements in the following 3 months.
- Texas: Drought improved a little over southeast Texas in May. Further relief can be expected in the following months.
- California: Drought intensified in May, is likely to persist in the following season.
- Central U.S. (Iowa, Missouri) – Watch for floods.