Articles | Volume 17, issue 7
Research article
20 Jul 2017
Research article |  | 20 Jul 2017

Meteorological analysis of flash floods in Artvin (NE Turkey) on 24 August 2015

Hakki Baltaci

Abstract. On 24 August 2015 intense rainfall episodes generated flash floods and landslides on the eastern Black Sea coast of Turkey. As a consequence of the heavy rainstorm activity over Artvin and its surroundings (NE Turkey), 11 people died and economic losses totaled a million dollars. Over the 6 h of the event (from 05:00 to 11:00 UTC), total accumulated rainfall amounts of 136, 64, and 109 mm were measured in the Hopa, Arhavi, and Borçka settlements of Artvin city, respectively. This study comprehensively investigates the meteorological characteristics of those flash floods. In terms of synoptic mechanisms, the cutoff surface low from the summer Asian monsoon settled over the eastern Black Sea. After two days of quasistationary conditions of this cyclone, sea surface temperatures (SSTs) reached 27.5 °C (1.5 °C higher than normal) and low-level moisture convergence developed. In addition, transfer of moisture by warm northerly flows from the Black Sea and relatively cool southerly flows from the land coasts of the Artvin district exacerbated the unstable conditions and thus played a significant role in the development of deep convective cells. Severe rainstorms as well as the slope instability of the region triggered landslides and worsened flood damages in the Artvin area. This study supports conventional weather analysis, satellite images, and forecast model output to alert forecasters to the potential for heavy rainfall.

Short summary
This paper investigated the meteorological role of an extraordinary rain event over Artvin. Although alert messages were prepared by the Turkish State Meteorological Service on August 23 at 09:00 UTC, 11 people died and infrastructures, buildings, private property, and public goods were damaged as a result of the flash flood. It is hoped that more detailed studies will be performed on synoptic development leading to extreme summer precipitation events in the eastern Black Sea.
Final-revised paper