Attributes of cut-off low induced rainfall over the Eastern Cape Province of South Africa

Cut-off low (COL) weather systems that are associated with rainfall over the Eastern Cape are considered in this study. COLs are objectively identified and tracked over a 31-year period. Daily rainfall data of 22 evenly distributed stations over the Eastern Cape are utilized. Only COLs with a minimu...

Full description

Saved in:
Bibliographic Details
Published in:Theoretical and applied climatology 2014-10, Vol.118 (1-2), p.307-318
Main Authors: Molekwa, S, Engelbrecht, C. J, Rautenbach, C. J. deW
Format: Article
Language:English
Subjects:
Analysis
Aquatic Pollution
Atmospheric circulation
Atmospheric Protection/Air Quality Control/Air Pollution
Atmospheric Sciences
autumn
Climate science
Climatology
Earth and Environmental Science
Earth Sciences
Earth, ocean, space
Exact sciences and technology
External geophysics
Hydrologic data
meteorological data
Meteorology
Original Paper
rain
Rain and rainfall
Rainfall
Rainfall measurement
Spatial distribution
spring
summer
Temperature
Waste Water Technology
Water in the atmosphere (humidity, clouds, evaporation, precipitation)
Water Management
Water Pollution Control
Winter
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Cut-off low (COL) weather systems that are associated with rainfall over the Eastern Cape are considered in this study. COLs are objectively identified and tracked over a 31-year period. Daily rainfall data of 22 evenly distributed stations over the Eastern Cape are utilized. Only COLs with a minimum spatial distribution, defined as more than a third of the rainfall stations that need to report rainfall on at least 1 day of a COL event, are considered for analysis of rainfall attributes. These attributes include the occurrence of COL rain days of different magnitudes, the distribution of the depth and temperature of the COL centres for the rain days of different magnitudes, the associated spatial distribution of rainfall as well as the associated atmospheric circulation. The frequency of COLs over the Eastern Cape has a winter maximum and a summer minimum. COL rain days of small, medium and large magnitudes occur most frequently during the winter, while small- and medium-magnitude COL rain days experience peaks in autumn and spring, respectively. The low-level flow, and in particular the position of the low/trough, seems to be the determinant factor in the occurrence, magnitude and spatial extent of COL-induced rainfall.
ISSN:0177-798X
1434-4483
DOI:10.1007/s00704-013-1061-3