6 November 2008
National Security Applications Program
Next Generation Operational Mesoscale
NWP Technology
Yubao Liu

All WMO/GTS
Wind Prof
GOES Radars
Modified WRF/MM5:
Dx/Dt = ... + GW (x obs
– x model
) where x = T, U, V, Q, P1, P2 …
W is weight function
RTFDDA
Regional-scale model, based on
WRF / MM5
Weather observations
Cold start
WRF/MM5
FDDA
Forecast t
MESONETs
Etc.
ACARS TAMDAR

• Olympics games
• Joint Urban 2003,
• Colorado wild fire
• FAA aviation weather
• Military operations
• Army test ranges
• Homeland security
• Xcel Energy
Collaborator
Universities:
CU, PSU, ASU, OU
UCAR:
MMM, CGD, UOP
RAL:
WSAP, HAP,
JNT, Aviation
• New York City
• 2005 Hurricanes
• AirDat TAMDAR
• …
12 Regular Operational RTFDDA Systems
20+ Special Operation Sites

Next-Gen 4DWX 4D-EnKF System
 Build “proper” mesoscale ensembles - heterogeneous

Incorporate Kalman Gain to obs-nudging weights
 Optimize model physics parameterization
Ensemble RTFDDA (NCAR/RAL)
(Obs-nudging ensembles)
Improvement areas:

Spatial and time weights
 Diverse data sources

Model physics schemes
Hybrids:

3DVAR
 VDRAS

Grid-nudging FDDA
WRF/MM5-RTFDDA: Obs-nudging

DPG E-RTFDDA Operation (Debut on 10 Sep. 2007)
T Mean and SD
Surface and X-sections
– Mean, Spread, Exceedance
Probability, Spaghetti, …
T-2m
Wind
Speed
Mean T & Wind
Wind
Rose
Likelihood for SPD > 10m/s
Pin-point Surface and Profiles
– Mean, Spread, Exceedance probability, spaghetti, Wind roses, Histograms …

E-RTFDDA represents a milestone advance in RAL
NWP capabilities and an important R&D frontier
It is the first in the world in terms of
 continuous ensemble analysis and forecasting
 multi-scale, down to 1 - 3 km grid
 dynamic perturbation optimization
 globally-relocatable
 and a Next-Gen NWP dev-bed for integration of
“cutting-edge” data assimilation technologies.

All U, V, T, Qv observations and data QC
WRF-
RTFDDA
WRF-
3DVAR
WRF
Hybrid
Engine
Upper-air U, V, T, Qv + Radar, satellite and other indirect obs

StageIV
(OBS)
C3DRAD
CNFCST
HYBRID
6 hour rain accumulation ended at 18Z
13 June 2002
( mm )

2-meter T, 9h fcsts, 4 pm
Warm hilly eddies
3 km
6 nested grids
DX= 30/10/3.3/1.1/0.369
/ 0.123 km
30” terrain and land use
37 sigma levels
24h forecasts: 12Z 16
Apr – 12Z 17 Apr 2008
Cold ocean flows
Small-terrain wind streaks
Phil
D.C.
Balt
Atlantic
Ocean

 A robust NWP system built upon WRF
 Lead FDDA R&D in WRF community
 Application-oriented research of WRF physics parameterizations
 Develop advanced data assimilation approach to take the advantages of new achievements by Community and ESSL
 Customized NWP products according to specific needs of diverse decision makers and end-users