Understanding heavy precipitation events in southern Israel through atmospheric electric field observations

Abstract

Characterizing the interaction between meteorological variables such as humidity, wind speed, cloud cover, and precipitation with the atmospheric electric field is vital for improving the nowcast of extreme weather events such as heavy precipitation. With this aim, we provide minute-scale electric field observations in southern Israel. These were taken during low-pressure weather systems in winter, often termed ‘Cyprus Lows.’ We focus only on precipitating (‘wet’) events, where rain was measured at the surface during and after the cold front's passage. The mean |PG| values for ‘wet’ Cyprus Lows are higher (Hundreds to thousands V m⁻¹) compared with the mean fair-weather values (∼100–200 V m⁻¹, and exhibit a sharp and rapid increase of the |PG| of up to tens of V m⁻¹ min⁻¹ during the arrival of the cold front and hundreds of V m⁻¹ min⁻¹ during precipitation. Then, we analyzed selected case studies in detail. The response of the |PG| to thunderstorm clouds, i.e., Cumulonimbus, is an increase to values of thousands of V m⁻¹. The temporal evolution of the |PG| allowed us to identify the type of cloud and its life cycle stage. We suggest that using state-of-the-art 1 Hz measurements of the |PG| and deducing cloud patterns at strategic locations, such as in arid regions like southern Israel, may improve the nowcasting capabilities of localized heavy precipitation events.