Forecast Improvements
NOAA/NWS/CSTAR – A Partnership to Develop, Conduct, and Evaluate Real-Time High-Resolution Ensemble and Deterministic Forecasts for Convective-Scale Hazardous Weather
Funding Type: CIMMS Task III (Program Manager – Sam Contorno)
Objectives
Apply cloud-resolving models to the explicit prediction of deep convection
using deterministic and ensemble approaches; understand the tradeoffs
in deterministic versus ensemble methodologies and the value of radar
data in initializing convection-resolving models; and understand how
convection-resolving forecasts can be utilized in operations as a move
toward warn-on-forecast concepts.
Accomplishments
This work is being conducted as part of the Spring 2007 Experiment of the
NOAA Hazardous Weather Test Bed. The experiments extended from 15 April
through 8 June 2007 with all forecasts run on dedicated NSF TeraGrid
resources at the National Center for Supercomputing Applications and
the Pittsburgh Supercomputing Center. The forecast suite included the
following each day:
- A 33-hour, 10-member, 2/3rds continental US-scale (CONUS) ensemble at 4 km grid spacing (run at PSC using a mixture of initial condition and physics perturbations);
- A 33-hour, single 2 km grid spacing deterministic forecast in the same domain as the ensembles;
- One or more six- to nine-hour nested grid forecasts at 2 km spacing launched automatically over regions of expected severe weather, as determined by mesoscale discussions or tornado watches (run at NCSA); and
- One six- to nine-hour nested grid forecast, per day, at 2 km grid spacing launched manually when and where deemed most appropriate (run at NCSA).
All forecasts were completed as planned and were a central component of daily discussions, during which some 47 visitors from academia and Federal laboratories participated from outside of Oklahoma. Because the grant supporting this activity began only in May, 2007, we have relatively few results and are analyzing data from the experiment, which was completed in early June (less than a month ago). However, preliminary results are extremely exciting and Steve Weiss of the SPC described the experiment as “groundbreaking.”
This project is ongoing.
Publications
Kong, F., M. Xue, K. K. Droegemeier, D. Bright, M. C. Coniglio, K. W. Thomas,
Y. Wang, D. Weber, J. S. Kain, S. J. Weiss, and J. Du, 2007: Preliminary
analysis on the real-time storm-scale ensemble forecasts produced as
a part of the NOAA hazardous weather testbed 2007 spring experiment. 22nd
Conf. Wea. Anal. Forecasting/18th Conf. Num. Wea. Pred., Salt Lake
City, UT, Amer. Meteor. Soc., CDROM 3B.2.
Weiss, S. J., J. S. Kain, D. R. Bright, J. J. Levit, G. W. Carbin, M. E. Pyle, Z. I. Janjic, B. S. Ferrier, J. Du, M. L. Weisman, and M. Xue, 2007: The NOAA Hazardous Weather Testbed: Collaborative testing of ensemble and convection-allowing WRF models and subsequent transfer to operations at the Storm Prediction Center. 22nd Conf. Wea. Anal. Forecasting/18th Conf. Num. Wea. Pred., Salt Lake City, UT, Amer. Meteor. Soc., CDROM 6B.4.
Xue, M., F. Kong, D. Weber, K. W. Thomas, Y. Wang, K. Brewster, K. K. Droegemeier, J. S. K. S. J. Weiss, D. R. Bright, M. S. Wandishin, M. C. Coniglio, and J. Du, 2007: CAPS realtime storm-scale ensemble and high-resolution forecasts as part of the NOAA hazardous weather testbed 2007 spring experiment. 22nd Conf. Wea. Anal. Forecasting/18th Conf. Num. Wea. Pred., Salt Lake City, UT, Amer. Meteor. Soc., CDROM 3B.1.
Forecast composite reflectivity ensemble mean (a) and spread (b), and ensemble-derived probability of composite reflectivity exceeding 35 dBZ (c) and the ‘spaghetti’ plot of 40 dBZ composite reflectivity contours(d), valid at 18 UTC, 24 May 2007, corresponding to a 21 hour forecast made with the WRF model as part of the 2007 Spring Experiment. From Xue et al. (2007)..