SLIDE 1 s
The Canadian Urban km and sub km- scale Weather Prediction System
WSN16, Hong Kong, 28 July 2016
Stephane Belair, Sylvie Leroyer, Lubos Spacek
Environment and Climate Change Canada Montreal, Canada
SLIDE 2 The NUMERICAL PREDICTION SYSTEM
10 km 2.5 km 0.25 km
4D-EnVAR CaLDAS
GEM GEM
48h forecasts 24h forecasts OP EXP
Atm. forcing UA ICs (downscaling)
(6h) (3h) (6h)
UA ICs + LBCs Surface ICs Buehner et al. (2015) Caron et al. (2015) Carrera et al. (2015) Milbrandt et al. (2016) Leroyer et al. (2014) Vionnet et al. (2015) Belair et al. (2016)
(1-km model)
SLIDE 3
The 2.5-km GEM
Column-max reflectivity
4 x 48h runs per day, MSC-Operations Transition of short-range guidance to this system 4D-EnVAR (10km) and CaLDAS (2.5km) for the initial conditions Upcoming... 4D-EnVAR at 2.5km and TEB for cities
SLIDE 4
GEM 0.25km CONFIGURATION
Implicit time scheme, semi-Lagrangian advection, terrain- following hybrid vertical coordinate – quite efficient and stable numerics / dynamics Urban processes with TEB Modified 1D turbulent mixing (mixing lengths proportional to model horizontal grid spacing) Milbrandt and Yau cloud microphysics scheme (6 categories, 2 moments) – P3 also being tested. Worth mentioning...
SLIDE 5
NEW FOCUS on 0.25km GEM
Coastal and mountain areas... tests over the Canadian West coast, tests over Sochi (Kiktev et al., submitted) Coastal urban areas … tests over Vancouver (Leroyer et al. 2014) Cities... tests over Oklahoma City (Husain et al. 2013, 2014) Mountains, tests over the Canadian Rockies (Vionnet et al. 2015) Severe weather over cities... tests over Tokyo (Belair et al., being submitted) ROCKIES VANCOUVER
SLIDE 6
PAN AM GAMES 2015… TORONTO
Interacting lake breezes (18 July 2014)
SLIDE 7 CLOUD COVER STRUCTURE
250 m 1 km MODIS
Aqua 250 m
Lake Breeze Fronts From MET-Objects analyses (19:00 UTC) AURORA Sills et al 2011
SLIDE 8 LAKE FRONT ANALYSES
1400 EDT Front analysis Met-Objects, AURORA
Front (model)
PBL height
SLIDE 9
TIME EVOLUTION of PBL HEIGHT
LAKE ONTARIO CITY of TORONTO NORTHERN SUBURBS STARTING on 0600 UTC 28 July 2015, ending 0600 UTC 29 July
SLIDE 10 INTENSE PRECIP OVER TOKYO (TOMACS)
OBS: PR (07UTC-06UTC)
(mm)
TOMACS... A field campaign in the Tokyo metropolitan area with dense observation network was conducted by MRI, NIED and 12 research groups for the summers
5 10 20 30 40 50 60 70 80 90
0.25km: PR (07UTC-06UTC)
(mm)
10 5 20 30 40 50 60 70 80 90
26 August 2011 19-h integration (Belair et al. 2016)
SLIDE 11 TIME SERIES of PRECIP OVER TOKYO AREA
Integration Hour % fraction area w/ Pr(1h) > 1 mm % fraction area w/ Pr(1h) > 10 mm % fraction area w/ Pr(1h) > 20 mm % fraction area w/ Pr(1h) > 30 mm
JMA analysis
CTRL NO_URB
Percent fraction area covered by hourly precipitation greater than 1, 10, 20, 30, and 50 mm.
(Belair et al. 2016)
SLIDE 12
IMPLEMENTATION STRATEGY (GEM 0.25 km)
A) Over a few selected areas... cities like Montreal, Toronto, Vancouver are first choice, but some have other ideas (e.g., northern areas, mountains) B) Anywhere, anytime... based on requests and events
SLIDE 13 IMPROVEMENTS DESIRED
2.5 km 0.25 km
4D-EnVAR CaLDAS
GEM GEM
48h forecasts 24h forecasts
UA ICs
(6h) (3h) (6h)
UA ICs + LCs Surface ICs
SPS (continuous)
Surface – low res analyses Surface – high res “analyses” Forcing
SLIDE 14
ALONG-TRACK GUIDANCE
(Courtesy of Zhipeng Qu and Howard Barker, ECCC)
SLIDE 15
COMPARISON with MODIS CLOUDS
(Courtesy of Zhipeng Qu and Howard Barker, ECCC)
SLIDE 16
FINAL WORDS
ECCC's high-resolution system not currently built for rapid refresh, with nowcasting applications Emphasis is on quality after spin up (> 6h forecasts) R&D for nowcasting + rapid refresh ongoing
