North American Drought Briefing: Monitoring

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North American Drought BriefingMonitoring
Forecasts

• Climate Prediction Center/NCEP/NOAA
• May 8, 2008
• http//www.cpc.ncep.noaa.gov/products/Drought

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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

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Outline

• 1. Drought Monitoring
• i) P (Accumulation Anomaly)
• ii) Indices (SPI, SRI)
• iii) Percentiles (Soil Moisture, Streamflow)
• iv) Means/Anomalies (SWE, Ts)
• v) Vegetation Fraction new!
• 2. Drought Forecasts
• GFS, ESP, CFS Downscaling, ENSO Condition
• 3. Summary

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1. Drought Monitoring
Hot spots Southeast California Texas, Dakotas
Changes reflected on 4/29 from 4/1 Southeast
improvement Southern Texas and California more
severe/developed
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CPC Precipitation Monitoring
Apr 2008
FMA 2008
http//www.cpc.ncep.noaa.gov/cgi-bin/US_anom_realt
ime.sh
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Heavy rainfall during April over Arkansas and
Missouri caused flooding.
Latitude
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Standardized Precipitation Index
In past 3 months California Drought continued
to develop Improvement SE, Dakotas
Drought D0 SPI lt -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 lt -2
(Data CPC grided P 1950-present)
http//www.cpc.ncep.noaa.gov/products/Drought/Drou
ght_index/Drought_index.shtml
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Standardized Runoff Index
Based on rolling monthly climatology ending on
20080503
(a) SRI (1-month)
(c) SRI (12-month)
(b) SRI (3-month)
(d) SRI (24-month)
http//www.hydro.washington.edu/forecast/monitor/i
ndices
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Soil Moisture Percentile for April 2008
(a) NARR
D4 D3 D2 D1 Drought D0 lt 20
(a) http//www.cpc.ncep.noaa.gov/products/Drought
/Drought_index/Drought_index.shtml
(b) (c) http//ldas.gsfc.nasa.gov/drought
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Streamflow Percentile 28-day Average obtained on
2008-05-04
Southeast RFC
flooding
http//waterdata.usgs.gov/waterwatch
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Snow Water Equivalent
(a) 2008-05-01
(b) 2008-03-01
(C) NLDAS Ensemble Apr 2008

• (b) National Snow Analyses http//www.nohrsc.nw
  s.gov

(c) CPC Drought Briefing http//www.cpc.ncep.noaa.
gov/products/Drought
Large positive anomalies over the western
mountains
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Current Drought Conditions based on SPI and Soil
Moisture Percentile

• Southeast condition improved in April, but soil
  moisture deficit continues
• Wetness extended from eastern Oklahoma
  northeastward to the Ohio Valley
• Drought developed in California
• Drought over Dakotas continues.
• Drought over southern Texas and New Mexico
  continues, while no large deficit shown in SRI
  and streamflow.

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Surface Temperature Anomaly
Apr 2008
Feb-Mar-Apr 2008
U.S. Temperature Analyses http//www.cpc.ncep.noa
a.gov/products/tanal/accesspage.shtml
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Vegetation Fraction
II. Apr 2008
I. 04/28-05/04
Data source ftp//ftp.orbit.nesdis.noaa.gov/pub/c
orp/scsb/wguo/data/GRIB/GVF_v4.0/Initial
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2. Drought Forecasts
Drought Tendency during May-July 2008
Improvement Southeast, Dakotas Persist/develop
Southwest from California to southern Texas
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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
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ESP Prediction SM Runoff Percentile
Initialized 20080419
(a) SM 1 month lead
(c) Accumulative Runoff 1 month lead
(b) SM 3 month lead
(d) Accumulative Runoff 3 month lead
http//www.hydro.washington.edu/forecast/monitor/o
utlook
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CFS Downscaling Forecasts SM Percentile
Initialized 200804
(a) May 2008
(b) Jun 2008
(c) Jul 2008
http//hydrology.princeton.edu/luo/research/FOREC
AST/fcstvrf.php
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SST anomalies for April 2008

• All NINO indices indicated that the cold ENSO
  weakened in April.
• CPCs ENSO Prognostic A transition from La Niña
  to ENSO-neutral conditions is possible in the
  next 2-3 months

Adapted from CPC Ocean Briefing
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ENSO Composites for P anomalies (MJJ)
If the cold ENSO weakens Do not expect
improvement for the Southeast Good for Texas
drought
warm
cold
neutral
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Summary

• Southeast Improved for the last few months/
  season. Forecasts show further improvement in the
  near future. However, if ENSO condition changes
  from cold to neutral, the improvement may not
  happen.
• Dakotas The drought condition persisted in past
  month. Forecasts show some improvement in the
  following 3 months.
• Taxes and California Drought conditions are
  likely to persist in next month. If the cold ENSO
  weakens, the drought may improve.
• California Summer is the dry season in
  California, so we may have to wait for rain.
  Watch for fire conditions.

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Current operational products
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