Handout (2.0 MB)
The National Weather Service in Mount Holly experiences a variety of weather threats
throughout the course of each year. Flash flooding is becoming one of the greatest warm-
season threats across the county warning area, as the frequency and severity of these events
have noticeably increased for various reasons (including broadening urbanization, more
frequent occurrences of anomalous tropospheric moisture content during the warm season,
etc.). This study discusses how the office’s approach to flash flood events has evolved in the
face of scientific and technological advances (e.g., the advent of polarimetric radar data and
increased spatiotemporal coverage of surface observations) and improvements with real-time
reporting (e.g., the rise of social media) as the flash flood events have changed over the past 15
years. Specifically, we will examine trends in flash flood warning operations and verification
during this period and provide case-study examples during the period to demonstrate the
changes in operational philosophy and methodology. We conclude by examining if and how
these operational changes have effectively utilized scientific, societal, and technological
advances in the field of flash flood forecasting and what still needs improvement.