An Unusual Extreme Rainfall Event in Canberra Australia on February 2018

Research output: Contribution to journalArticle

Abstract

A case of an extreme rainfall event in Canberra, the capital city of Australia, on 24–25 February 2018 is investigated. Canberra received more than the long-term statistical February total rainfall within 6 hr on that day, causing overwhelming flash flooding in the city. In contrast to many coastal cities or tropical regions, Canberra is located at the boundary between the tropics and extratropics and is usually dry and warm in February. The diagnostic analysis shows that this relatively rare brief heavy rainfall was the joint effects of lower-level warm, moist conveyor belts, the remnants of tropical cyclone Kelvin, surface cold fronts, and a midlatitude trough at middle to upper levels. The lower-level northeast and west conveyor belts of water vapor contributed to the accumulation of moisture and created favorable conditional instability over Canberra by transporting tropical moist and warm air from Coral Sea and from the Kelvin remnant to Canberra prior to and during the rainfall period. Enhanced uplift was triggered by the arrival of a cold front in the warm, moist unstable air. The rainfall reached a peak 13.6 mm in 30 min soon after a low-level frontal updraft coupled with middle- to upper-level dynamical uplift ahead of the midlatitude trough. After the passage of the upper-level trough, the dry, cold air in the rear of the trough stabilized and dried the atmosphere above Canberra. The rainfall decreased and ended rapidly.

Original languageEnglish (US)
Pages (from-to)4429-4445
Number of pages17
JournalJournal of Geophysical Research: Atmospheres
Volume124
Issue number8
DOIs
StatePublished - Apr 27 2019
Externally publishedYes

Fingerprint

Rain
troughs
rain
rainfall
trough
cold fronts
cold front
temperate regions
tropical regions
air
tropics
Air
uplift
vertical air currents
Coral Sea
Tropics
cyclones
capital city
hurricanes
cold air

ASJC Scopus subject areas

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Space and Planetary Science
  • Earth and Planetary Sciences (miscellaneous)
  • Palaeontology

Cite this

An Unusual Extreme Rainfall Event in Canberra Australia on February 2018. / Deng, Difei; Ritchie, Elizabeth A.

In: Journal of Geophysical Research: Atmospheres, Vol. 124, No. 8, 27.04.2019, p. 4429-4445.

Research output: Contribution to journalArticle

@article{ebeaa139d3fb44b5bbf0251fa734452c,
title = "An Unusual Extreme Rainfall Event in Canberra Australia on February 2018",
abstract = "A case of an extreme rainfall event in Canberra, the capital city of Australia, on 24–25 February 2018 is investigated. Canberra received more than the long-term statistical February total rainfall within 6 hr on that day, causing overwhelming flash flooding in the city. In contrast to many coastal cities or tropical regions, Canberra is located at the boundary between the tropics and extratropics and is usually dry and warm in February. The diagnostic analysis shows that this relatively rare brief heavy rainfall was the joint effects of lower-level warm, moist conveyor belts, the remnants of tropical cyclone Kelvin, surface cold fronts, and a midlatitude trough at middle to upper levels. The lower-level northeast and west conveyor belts of water vapor contributed to the accumulation of moisture and created favorable conditional instability over Canberra by transporting tropical moist and warm air from Coral Sea and from the Kelvin remnant to Canberra prior to and during the rainfall period. Enhanced uplift was triggered by the arrival of a cold front in the warm, moist unstable air. The rainfall reached a peak 13.6 mm in 30 min soon after a low-level frontal updraft coupled with middle- to upper-level dynamical uplift ahead of the midlatitude trough. After the passage of the upper-level trough, the dry, cold air in the rear of the trough stabilized and dried the atmosphere above Canberra. The rainfall decreased and ended rapidly.",
author = "Difei Deng and Ritchie, {Elizabeth A}",
year = "2019",
month = "4",
day = "27",
doi = "10.1029/2019JD030420",
language = "English (US)",
volume = "124",
pages = "4429--4445",
journal = "Journal of Geophysical Research: Space Physics",
issn = "2169-9380",
publisher = "Wiley-Blackwell",
number = "8",

}

TY - JOUR

T1 - An Unusual Extreme Rainfall Event in Canberra Australia on February 2018

AU - Deng, Difei

AU - Ritchie, Elizabeth A

PY - 2019/4/27

Y1 - 2019/4/27

N2 - A case of an extreme rainfall event in Canberra, the capital city of Australia, on 24–25 February 2018 is investigated. Canberra received more than the long-term statistical February total rainfall within 6 hr on that day, causing overwhelming flash flooding in the city. In contrast to many coastal cities or tropical regions, Canberra is located at the boundary between the tropics and extratropics and is usually dry and warm in February. The diagnostic analysis shows that this relatively rare brief heavy rainfall was the joint effects of lower-level warm, moist conveyor belts, the remnants of tropical cyclone Kelvin, surface cold fronts, and a midlatitude trough at middle to upper levels. The lower-level northeast and west conveyor belts of water vapor contributed to the accumulation of moisture and created favorable conditional instability over Canberra by transporting tropical moist and warm air from Coral Sea and from the Kelvin remnant to Canberra prior to and during the rainfall period. Enhanced uplift was triggered by the arrival of a cold front in the warm, moist unstable air. The rainfall reached a peak 13.6 mm in 30 min soon after a low-level frontal updraft coupled with middle- to upper-level dynamical uplift ahead of the midlatitude trough. After the passage of the upper-level trough, the dry, cold air in the rear of the trough stabilized and dried the atmosphere above Canberra. The rainfall decreased and ended rapidly.

AB - A case of an extreme rainfall event in Canberra, the capital city of Australia, on 24–25 February 2018 is investigated. Canberra received more than the long-term statistical February total rainfall within 6 hr on that day, causing overwhelming flash flooding in the city. In contrast to many coastal cities or tropical regions, Canberra is located at the boundary between the tropics and extratropics and is usually dry and warm in February. The diagnostic analysis shows that this relatively rare brief heavy rainfall was the joint effects of lower-level warm, moist conveyor belts, the remnants of tropical cyclone Kelvin, surface cold fronts, and a midlatitude trough at middle to upper levels. The lower-level northeast and west conveyor belts of water vapor contributed to the accumulation of moisture and created favorable conditional instability over Canberra by transporting tropical moist and warm air from Coral Sea and from the Kelvin remnant to Canberra prior to and during the rainfall period. Enhanced uplift was triggered by the arrival of a cold front in the warm, moist unstable air. The rainfall reached a peak 13.6 mm in 30 min soon after a low-level frontal updraft coupled with middle- to upper-level dynamical uplift ahead of the midlatitude trough. After the passage of the upper-level trough, the dry, cold air in the rear of the trough stabilized and dried the atmosphere above Canberra. The rainfall decreased and ended rapidly.

UR - http://www.scopus.com/inward/record.url?scp=85065203594&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85065203594&partnerID=8YFLogxK

U2 - 10.1029/2019JD030420

DO - 10.1029/2019JD030420

M3 - Article

AN - SCOPUS:85065203594

VL - 124

SP - 4429

EP - 4445

JO - Journal of Geophysical Research: Space Physics

JF - Journal of Geophysical Research: Space Physics

SN - 2169-9380

IS - 8

ER -