Impacts of Non-Local versus Local Moisture Sources on a Heavy (and Deadly) Rain Event in Israel

A deadly rain event in Israel's semi-arid Negev desert, particularly around the Tzafit river gorge near Dimona, was significantly influenced by both local and non-local moisture sources. Research using factor separation techniques revealed that local ground moisture substantially increased Convective Available Potential Energy (CAPE), leading to heightened precipitation and lightning rates, especially near Jerusalem. Meanwhile, non-local moisture sources facilitated weak but widespread convection, with localized peaks in the Tzafit river area. The combined effect of these moisture sources intensified convective activity, contributing to severe flooding on April 26, 2018. This study underscores the importance of accurately depicting soil moisture in forecast models for the Levant, particularly during the typically dry spring season, to improve predictions of convective rainfall and associated hazards.

Lynn, B., Yair, Y., Levi, Y., Ziv, S. Z., Reuveni, Y., & Khain, A. (2021). Impacts of Non-Local versus Local Moisture Sources on a Heavy (and Deadly) Rain Event in Israel. Atmosphere, 12(7), 855. https://doi.org/10.3390/atmos12070855