Effects of Moist Convection on Mesoscale Predictability

• DOI: 10.1175/1520-0469(2003)060<1173:eomcom>2.0.co;2
• Publication Date: 2003-04-16T17:09:10Z
• Authors: F. Zhang; Chris Snyder; Richard Rotunno
• Keywords: Predictability; Convective storm detection; Mesoscale convective system

In a previous study by the authors, it was shown that problematic numerical prediction of 24–25 January 2000 snowstorm along east coast United States in some measure due to rapid error growth at scales below 500 km. particular they found moist processes were responsible for this strong initial-condition sensitivity 1–2-day mesoscale forecast aspects. present take more systematic look which small initial differences ("errors") grow those forecasts. For errors restricted 100 km, results show first as small-scale associated with convection, then spread upscale their begins slow. context predictions 30-km resolution, is nonlinearities convective parameterization (or explicit microphysical parameterizations, if no used) and proceeds rate increases amplitude decreases. higher-resolution (3.3 km) simulations, timing position individual cells. Amplification stage occurs on timescale order 1 h, comparable convection. The convective-scale motions subsequently influence development meso- larger-scale aspects such surface low distribution precipitation, thus providing evidence from places an intrinsic limit predictability larger scales.