development and evaluation of a operational fine-scale nwp...

CMOS/AMS Conference May 31 2012, Montreal, Canada

Development and Evaluation of a

Operational Fine-scale NWP Model

Wanli Wu Y. Liu, L. Pan, YW. Liu, W. Cheng, J. Knievel, J. Pace

National Center for Atmospheric Research

Boulder, Colorado, USA

CMOS/AMS Conference May 31 2012, Montreal, Canada

q Motivation

q NWP Model

q Evaluation Experiments

q Summary

OUTLINE

CMOS/AMS Conference May 31 2012, Montreal, Canada

v Increasing demands for fine-scale weather forecasting

v Advances in understanding of weather system & in

model development including data assimilation v Transfer Research to Operation

Motivation

CMOS/AMS Conference May 31 2012, Montreal, Canada

Research Applications Laboratory at NCAR has been developing an operational fine-scale NWP model:

o Weather Research and Forecasting (WRF) model o Capability resolving LES-scale turbulence (Moeng et

al.,2006): Smograrisky sub-grid scale (SGS) model

o Real-time data assimilation system (Liu et al.,2011)

o Ultra-high resolution landuse (NLCD 2006) and terrain (SRTM) data at ~30m

Fine-scale Numerical Weather Prediction Model

CMOS/AMS Conference May 31 2012, Montreal, Canada

Model Configuration

o One-way nested domains: 8.1, 2.7, 0.9, 0.3, 0.1 km

o Data Assimilation on 8.1, and 2.7 km domains

o Turbulence explicitly resolved by Smagorinsky SGS model in 0.3 and 0.1 km domains, Nonlinear Backscatter Anisotropic subgrid stress, 3D TKE K coefficients

o IC & LBC: 12-km NAM model o WSM6,RRTMG, Noah, Kain-Fritsch,YSU

CMOS/AMS Conference May 31 2012, Montreal, Canada

Sample results from testing experiments

1. Topographic flow

2. Wind farm simulation

3. severe weather simulation: April 2011 Super Tornado Outbreak

CMOS/AMS Conference May 31 2012, Montreal, Canada

Simulated Topographic Flow @ 300m near Dugway, Utah (July 14 2010, 12UTC)

Background: Terrain Vector: 10m wind Red arrow: observed wind White contour: 2m temperature Resolved fine-scale topographic flow, vortex

CMOS/AMS Conference May 31 2012, Montreal, Canada

Simulated near-surface wind variation in wind farm near Colorado-Wyoming Stateline (@ 100m, Oct. 20 2009, 18UTC

OBS MODEL

CMOS/AMS Conference May 31 2012, Montreal, Canada

April 25-28 2011 Southeastern U.S. Super tornado outbreak

CMOS/AMS Conference May 31 2012, Montreal, Canada

Simulated three episodes Tornado-like surface winds (@ 300m) 09:00UTC 27th - 00:00UTC 28th , April, 2011

CMOS/AMS Conference May 31 2012, Montreal, Canada

Spatial distribution of simulated tornado-like near-surface winds: 09:00UTC 27th – 00:00UTC 28th, April 2011

CMOS/AMS Conference May 31 2012, Montreal, Canada

Modeled 10-m winds and 5-minutes accumulated rainfall (27th April 2011 09:20UTC)

Surface Wind (dots: EF0 or greater) Precipitation (background color

Storm-Relative Helicity

CMOS/AMS Conference May 31 2012, Montreal, Canada

Simulated 10-m winds and vertical velocity at 700 m 27th April 2011 22: 05 UTC

CMOS/AMS Conference May 31 2012, Montreal, Canada

Simulated Tornado Evolution

OBS

76m/s

25 hPa

CMOS/AMS Conference May 31 2012, Montreal, Canada

Surface Flow Sensitivity to Model Resolution Resolution

CMOS/AMS Conference May 31 2012, Montreal, Canada

Surface Wind Verification (two weeks forecast mean at 300m domain)

OBS

Model

CMOS/AMS Conference May 31 2012, Montreal, Canada

Summary The NWP model with turbulence-resolving capability is able to reasonably simulate fine-scale topographic flow, intra-wind farm variability and severe mesocyclone, supercell vortex including features in tornado genesis. Further development and evaluation are in progress including LES-scale model, fine-scale data assimilation, two-way nesting, high-resolution soil type data.