Identification

Title

Mechanisms for a record-breaking rainfall in the coastal metropolitan city of Guangzhou, China: Observation analysis and nested very large eddy simulation with the WRF Model

Abstract

Record-breaking rainfall of 524.1mm in 24hr occurred in the coastal metropolitan city of Guangzhou, China, during 6-7 May 2017 and caused devastating flooding. Observation analysis and a nested very large eddy simulation (VLES) with Weather Research and Forecasting (WRF) model were conducted to investigate various factors that contributed to the heavy rainfall, including synoptic weather pattern, topographic effects, cold pool, and urban effects. First, the warm and moist southerly flow in the lower troposphere over the trumpet-shaped topography of the Pearl River Delta continuously provided fuel for the development of the severe rainfall. Consequently, the southerly flow from the sea in the south strengthened with the development of the convection. Meanwhile, the precipitation-produced weak cold pool supported a stationary outflow boundary, where new convective cells were continuously initiated and drifted downstream. The interaction between the cold outflows and the warm moist southerly flows in the lower troposphere formed a back-building convective system, which produced local persistent heavy rainfall that lasted for more than 5hr and reached record levels. Sensitivity experiments in which the urban area was removed from the model indicate that the urban forcing affected the timing and location of convective initiation and helped concentrate the maximum rain core. The nested WRF-LES successfully simulated this heavy rainfall, and the model's advantages are noted for forecasting such local severe weather.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7h1351s

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2019-02-16T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact