Correlation coefficients of precipitation anomaly (P) and temperature
anomaly (T) in North Central Texas and major climate indices (AMO,
PDO, SOI, NAO) during El Nino climate condition from 1960 to 2014.
Climate Forecast-Aided Drought Decision Support for North Central Texas
Sunghee Kim1, Hossein Sadeghi1, D.-J. Seo1, Andrew Philpott2, Frank Bell2, Tyler Fincannon3, Arne Winguth3, Reza Ahmad Limon1, Laura Blaylock4, James Brown5, Nick Fang1, Glenn Clingenpeel6
1Dept. of Civil Eng, The Univ. of Texas at Arlington, Arlington, TX, USA, 2West Gulf River Forecast Center, NOAA/NWS, Fort Worth, TX, USA, 3Dept. of Earth & Environ. Sciences, The Univ. of Texas at
Arlington, Arlington, TX, USA; 4Tarrant Regional Water District, Fort Worth, TX, USA, 5Hydrologic Solutions Limited, Southampton, UK, 6 Trinity River Authority of Texas, Arlington, TX, USA
Background
Extreme events pose increasingly large challenges
for water supply and flood control to the Dallas-Fort
Worth Metroplex (DFW) and North Central Texas,
exacerbated by rapid population growth, urbanization
and climate change.
To meet the growing demand for water supply, large
raw water suppliers such as the Tarrant Regional
Water District (TRWD) operate systems of reservoirs
interconnected by extensive networks of pipelines.
Approach – Phase 1
594, Wednesday, January 13, 2016 02:30 PM - 04:00 PM, AMS 96th Annual Meeting, New Orleans, LA
Perform hindcasting experiments using weather and
climate reforecasts from the Global Ensemble Forecast
System (GEFS), Coupled Forecast System Model
Version 2 (CFSv2) and conditional ensemble
streamflow prediction using climate indices
Produce streamflow ensemble hindcasts using the
Hydrologic Ensemble Forecast Service (HEFS) on the
NWS Community Hydrologic Prediction System
(CHPS)
Input ensemble streamflow hindcasts to the TRWD’s
decision support tool, RiverWare
Conclusions
• The use of medium-range ensemble
precipitation forecast can substantially
increase lead time and skill of inflow
forecast in North Central Texas
‒ Significant skill observed in
weekly inflow volume forecast out
to 2 weeks into the future
Acknowledgments This work is supported by the Sectoral Applications Research Program (SARP) of the NOAA Climate
Program Office (CPO) Grant NA15OAR4310109. This support is gratefully acknowledged.
Objectives
Utilize weather and climate forecast-forced
ensemble streamflow forecast in water resources
management practices in North Central Texas
‒ Currently, the NWS West Gulf River Forecast
Center (WGRFC) provides only short-range (~3
days) single-valued precipitation forecast (QPF)
Assess predictive skill and economic value of
weather and climate forecasts for integrated decision
support for reservoir management and water supply
operations in North Central Texas
Advance understanding of the role of weather and
climate forecasts in improving reliability, efficiency
and resilience of a complex water supply system in a
large and rapidly growing urban area
Method Study area
Preliminary Results
Using GEFS-forced, post-processed ensemble
streamflow forecasts as inflows, the TRWD
model simulates the reservoir and water
transfer operations, evaluating the effectiveness
and benefits of weather and climate forecast-
aided decision support.
Perc
ent
Non-E
xceedance
Dollars in Millions
Annual Cost
Savings Additional
Annual Cost
(1) Climate indices
(2) Skill in precipitation hindcasts:
Medium-range (GEFS) vs. Short-range (WGRFC QPF)
(4) Skill in total inflow volume
(3) Skill in ensemble streamflow hindcasts
Skill in weekly inflow volume
hindcasts remains significant up
to about 14 days into the future
NWS Hydrologic Ensemble Forecast Service (HEFS) on Community Hydrologic Prediction System (CHPS)
TRWD model
GEFS reforecasts (Ensemble mean)
MEFP
MEFP parameters
Ensemble precipitation hindcasts
Hydrologic &
reservoir models
Raw ensemble streamflow hindcasts
EnsPost parameters
EnsPost
Post-processed ensemble streamflow hindcasts
Meteorological Ensemble Forecast
Processor
Ensemble Post Processor
Lead time (hours)
Co
rre
latio
n c
oe
ffic
ien
t
Lead time (hours)
Co
rre
latio
n c
oe
ffic
ien
t GEFS ensemble
mean
RFC single-valued
QPF
Streamflow (cfs)
Obs. CDF
Forecast CDF
Cu
mu
lative
De
nsity
CR
PS
S
Lead time (hours)
CRPSS (relative to climatology)
remains significant for about 10
days into the future
Co
rre
latio
n c
oe
ffic
ien
t
Lead time (hours)
Mean Continuous Ranked Probability:
𝑪𝑹𝑷𝑺 = { 𝑭𝒀 𝒒 − 𝑭𝑿 𝒒𝟐 𝒅𝒚
Ongoing work
• Use the weather and climate
forecast-aided ensemble inflow
volume forecast in TRWD’s decision
support tool
‒ CFSv2 via HEFS
‒ Climate indices via conditional
ESP using HEFS
TRWD’s water supply system
NA
O
SO
I
PD
O
A
MO
P(J
AK
T2
)
P
(DF
W)
T(D
FW
)
T(DFW) P(DFW) P(JAKT2) AMO PDO SOI NAO
• Regional mean areal precipitation anomaly, P(JAKT2) shows
statistically significant correlation with indices PDO (=0.57),
NAO (= 0.31), AMO (= -0.31), and SOI (= -0.35).
• P(JAKT2) has moderate correlation with temperature
anomaly in the DFW area (=-0.23).
An example of cost-benefit analysis