Very-high-resolution single-sounding tornado simulations
Prediction of May 8, 2003 case (Hu and Xue)
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Prediction of May 8, 2003 case (Hu and Xue)Using the ARPS and its 3DVAR and cloud analysis DA system, Hu et al. (2006a; 2006b), and earlier Xue et al. (2003) were able to successfully capture, with more than 1-hour lead time, the low-level intensification of rotation in supercell that spawned two tornadoes in downtown Fort Worth on 28 March 2000, with good timing and location. More recently, Xue and Hu (2007) obtained a successful prediction of the tornado of 8 May 2003 in the OKC area, using nested grids of up to 50 m horizontal resolution, and by assimilating radar data on a 1-km grid over a 70-min time window (Hu and Xue 2007; Xue et al. 2007). A the 50-m grid was able to capture, with almost exact timing, the intensification of tornadic vortices. The track error was of less than 8 km and the track had a correct orientation. The low-level reflectivity at 33.75 minutes of 50-m forecast is shown in Fig. 6, together with observed reflectivity at a similar time. The predicted field shows a pronounced hook containing an inwardly spiraling reflectivity feature which compares favorably with the observation. The low-level velocity, vorticity, perturbation pressure fields also show many features consistent with tornadoes (Xue et al. 2007; Xue and Hu 2007). 
Fig. 6. Predicted surface reflectivity field on the 50-m grid valid at 2213:45 UTC (a), and observed reflectivity at the 1.45° elevation of OKC radar at 2216 UTC (b). Caption for animation: ARPS model simulated radar reflectivity for the May 8, 2003 OKC tornadic thunderstorm (left) as compared to radar observation. Simulation is updated very half a minute while the observation is updated very 5 minute. Simulation was performed using 50 m resolution. http://twister.ou.edu/tornado/jan_thunderstorm_withCaption.mpg is the link to the 3D movie – but it was done at PSC. Hu, M. and M. Xue, 2007: Analysis and prediction of 8 May 2003 Oklahoma City tornadic thunderstorm and embedded tornado using ARPS with assimilation of WSR-88D radar data. 22nd Conf. Wea. Anal. Forecasting/18th Conf. Num. Wea. Pred., Salt Lake City, Utah, Amer. Meteor. Soc., CDROM 1B.4. Hu, M., M. Xue, and K. Brewster, 2006a: 3DVAR and cloud analysis with WSR-88D level-II data for the prediction of Fort Worth tornadic thunderstorms. Part I: Cloud analysis and its impact. Mon. Wea. Rev., 134, 675-698. Hu, M., M. Xue, J. Gao, and K. Brewster, 2006b: 3DVAR and cloud analysis with WSR-88D level-II data for the prediction of Fort Worth tornadic thunderstorms. Part II: Impact of radial velocity analysis via 3DVAR. Mon. Wea. Rev., 134, 699-721. Xue, M., 2004: Tornadogenesis within a simulated supercell storm. Abstract, 22nd Conf. Severe Local Storms., Hyannis, Massachusetts,, Amer. Meteor. Soc. Xue, M., 2006: Tornadogenesis and tornado dynamics as revealed by ultra-high-resolution numerical simulations of a tornadic thunderstorm. The Doug Lilly Symposium, Atlanta, GA, Amer. Meteor. Soc. Xue, M. and M. Hu, 2007: Numerical prediction of 8 May 2003 Oklahoma City supercell tornado with ARPS and radar data assimilation. Geophys. Res. Letters, In review.
Xue, M., D.-H. Wang, J.-D. Gao, K. Brewster, and K. K. Droegemeier, 2003: The Advanced Regional Prediction System (ARPS), storm-scale numerical weather prediction and data assimilation. Meteor. Atmos. Physics, 82, 139-170. Directory: pub pub -> Project Scoring Template Pre-Construction Phase New Core/Branch Campus Projects pub -> Acm word Template for sig site pub -> The german unification, 1815-1870 pub -> Baltic Olympiads in Informatics: Challenges for Training Together pub -> Preparation of Papers for ieee transactions on medical imaging pub -> Forthcoming meetings and conferences pub -> Asilomar Conference on Circuits, Systems & Computers, Pacific Grove, ca, November 1978, pp. 55 58 pub -> Forthcoming meetings and conferences pub -> Harmonised compatibility and sharing conditions for video pmse in the 7 9 ghz frequency band, taking into account radar use Download 0.63 Mb. Share with your friends:
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