Identification

Title

Toward improved short-term forecasting for Lake Victoria Basin. Part II: Preconvective environment analysis with ERA5

Abstract

Lake Victoria is the largest freshwater lake in Africa, with around 30 million people living on its coastline, and it serves as one of the largest natural resources for East African communities due to its prosperous fishing industry. However, around 1000 fishermen die annually on the lake due to severe weather-related accidents. Radar-based research from the “High Impact Weather Lake System” (HIGHWAY) project in 2019 confirmed the marked diurnal cycle on Lake Victoria, studied over decades, where organized, intense convective systems pose a major risk to the fishermen operating overnight. Building upon the results from Part I of this study, we investigate the preconvective environment over the lake for the modes that have been previously identified with a radar-based classification for the two wet seasons in 2019. ERA5 reanalysis data show that in 2019, instability and steeper low-level lapse rates were higher during season I [March–May (MAM)], allowing unorganized storms overnight to have stronger downdrafts, increasing the potential for strong and damaging winds over the lake. Second, the multicell linear mode in season II [October–December (OND)] and at nighttime presents significantly low RH 700–500hPa , which might indicate potential strong winds at the surface (evaporative cooling). Third, bulk shear was higher in season I 2019 for almost all modes, with some modes indicating the capacity to organize into multicell systems and even some to have rotating updrafts. Finally, some modes in season I, at nighttime and early morning, present high storm-relative helicity values in midlevels, which, combined with high bulk shear, may lead to embedded rotations in dynamically complex systems.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.net/ark:/85065/d74q80d1

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

2025-06-01T00:00:00Z

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