---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '21995'
abstract:
- lang: eng
  text: On 26–28 September 2024, torrential rainfall struck Nepal during the late
    monsoon season, causing flooding, landslides and extensive damage. This study
    examined the multiscale processes contributing to this extreme precipitation event,
    focusing on intraseasonal oscillations, synoptic-scale circulations, and mesoscale
    cloud/precipitation systems. A quasi-biweekly intraseasonal oscillation dominated
    over South Asia during the event, featuring a monsoon low-pressure system over
    the Indian Peninsula and an anticyclone to its east, both propagating westward.
    The pressure gradient between them sustained strong southerly moisture transport
    toward the Himalayas, establishing a persistently humid environment and orographic
    lift along the southern slopes. In contrast to reports of previous extreme precipitation
    events in Nepal, the atmospheric circulation responsible for the 2024 event was
    primarily of tropical origin, with minimal influence from the midlatitudes. Characteristic
    mesoscale cloud/precipitation systems also developed around the Himalayas. The
    highest daily precipitation during the event was recorded on 27 September; stratiform
    systems with relatively modest storm top heights developed over the southern slopes,
    generating surface precipitation rates of > 100 mm h− 1 through warm-rain processes.
    Rain gauges across the glacierized basin (3500–5000 m asl) recorded exceptionally
    high daily and hourly precipitation rates, highlighting the extension of intense
    rainfall to unusually high elevations.
acknowledgement: 'This work was supported by the Japan Society for the Promotion of
  Science (JSPS) (KAKENHI Grants: 22H00176, 22H00033, 22H00037, and 23KK0064). It
  was partly supported by the 4th Research Announcement on the Earth Observations
  of the Japan Aerospace Exploration Agency (JAXA). It was partly carried out under
  the joint research program of Institute for Space–Earth Environmental Research,
  Nagoya University and as a joint research program with the Center for Environmental
  Remote Sensing (CEReS), Chiba University (CJ25-43, 2025). We thank James Buxton
  MSc and Tina Tin PhD from Edanz (https://jp.edanz.com/ac), for editing a draft of
  this manuscript. The Japan Society for the Promotion of Science (JSPS) supports
  this work (KAKENHI Grants: 22H00176, 22H00033, 22H00037, and 23KK0064).'
article_number: '27'
article_processing_charge: Yes
article_type: original
author:
- first_name: Hatsuki
  full_name: Fujinami, Hatsuki
  last_name: Fujinami
- first_name: Nobuhiro
  full_name: Takahashi, Nobuhiro
  last_name: Takahashi
- first_name: Hironari
  full_name: Kanamori, Hironari
  last_name: Kanamori
- first_name: Yota
  full_name: Sato, Yota
  id: daa9e17a-f2c2-11ef-b968-915e836dea45
  last_name: Sato
- first_name: Sojiro
  full_name: Sunako, Sojiro
  last_name: Sunako
- first_name: Masaya
  full_name: Kato, Masaya
  last_name: Kato
- first_name: Atsushi
  full_name: Higuchi, Atsushi
  last_name: Higuchi
- first_name: Indira
  full_name: Kadel, Indira
  last_name: Kadel
- first_name: Dibas
  full_name: Shrestha, Dibas
  last_name: Shrestha
- first_name: Rijan B.
  full_name: Kayastha, Rijan B.
  last_name: Kayastha
- first_name: Koji
  full_name: Fujita, Koji
  last_name: Fujita
citation:
  ama: Fujinami H, Takahashi N, Kanamori H, et al. Multiscale aspects of an extreme
    precipitation event over Nepal in September 2024. <i>Scientific Online Letters
    on the Atmosphere</i>. 2026;22. doi:<a href="https://doi.org/10.1007/s44393-026-00024-0">10.1007/s44393-026-00024-0</a>
  apa: Fujinami, H., Takahashi, N., Kanamori, H., Sato, Y., Sunako, S., Kato, M.,
    … Fujita, K. (2026). Multiscale aspects of an extreme precipitation event over
    Nepal in September 2024. <i>Scientific Online Letters on the Atmosphere</i>. Springer
    Nature. <a href="https://doi.org/10.1007/s44393-026-00024-0">https://doi.org/10.1007/s44393-026-00024-0</a>
  chicago: Fujinami, Hatsuki, Nobuhiro Takahashi, Hironari Kanamori, Yota Sato, Sojiro
    Sunako, Masaya Kato, Atsushi Higuchi, et al. “Multiscale Aspects of an Extreme
    Precipitation Event over Nepal in September 2024.” <i>Scientific Online Letters
    on the Atmosphere</i>. Springer Nature, 2026. <a href="https://doi.org/10.1007/s44393-026-00024-0">https://doi.org/10.1007/s44393-026-00024-0</a>.
  ieee: H. Fujinami <i>et al.</i>, “Multiscale aspects of an extreme precipitation
    event over Nepal in September 2024,” <i>Scientific Online Letters on the Atmosphere</i>,
    vol. 22. Springer Nature, 2026.
  ista: Fujinami H, Takahashi N, Kanamori H, Sato Y, Sunako S, Kato M, Higuchi A,
    Kadel I, Shrestha D, Kayastha RB, Fujita K. 2026. Multiscale aspects of an extreme
    precipitation event over Nepal in September 2024. Scientific Online Letters on
    the Atmosphere. 22, 27.
  mla: Fujinami, Hatsuki, et al. “Multiscale Aspects of an Extreme Precipitation Event
    over Nepal in September 2024.” <i>Scientific Online Letters on the Atmosphere</i>,
    vol. 22, 27, Springer Nature, 2026, doi:<a href="https://doi.org/10.1007/s44393-026-00024-0">10.1007/s44393-026-00024-0</a>.
  short: H. Fujinami, N. Takahashi, H. Kanamori, Y. Sato, S. Sunako, M. Kato, A. Higuchi,
    I. Kadel, D. Shrestha, R.B. Kayastha, K. Fujita, Scientific Online Letters on
    the Atmosphere 22 (2026).
dataavailabilitystatement: Daily rainfall data across Nepal were obtained from the
  Department of Hydrology and Meteorology, Kathmandu, Nepal (https://dhm.gov.np/).
  Precipitation data from Pyramid observatory are available from [https://glacioclim.osug.fr/Donnees-du-Nepal-region-du-Khumbu](https:/glacioclim.osug.fr/Donnees-du-Nepal-region-du-Khumbu)
  . Precipitation data from rain gauges in Rolwaling valley are available from https://doi.org/10.5281/zenodo.18081206.
  NOAA’s Climate Prediction Center provided daily OLR data ( [https://psl.noaa.gov/data/gridded/data.cpc\_blended\_olr-2.5
  deg.html](https:/psl.noaa.gov/data/gridded/data.cpc_blended_olr-2.5 deg.html) ).
  We used infrared brightness temperature data from MSG2 (Meteosat 9)-IODC. The Center
  for Environmental Remote Sensing (CEReS), Chiba University, archived and provided
  the data (https://ceres.chiba-u.jp/en/ top-eng/). The GPM DPR products are available
  from the Japan Aerospace Exploration Agency (JAXA) G-Portal website ( [https://gportal.jaxa.jp/gpr/](https:/gportal.jaxa.jp/gpr)
  ). The ERA5 data are available from the Copernicus climate-change service (C3S)
  climate data store (https://doi.org/10.24381/cds.bd0915c6). GMTED2010 data are available
  from the US Geological Survey (https://topotools.cr.usgs.gov/gmted\_viewer/viewer.htm).
date_created: 2026-06-14T22:01:42Z
date_published: 2026-06-04T00:00:00Z
date_updated: 2026-06-22T11:26:52Z
day: '04'
ddc:
- '550'
department:
- _id: FrPe
doi: 10.1007/s44393-026-00024-0
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has_accepted_license: '1'
intvolume: '        22'
language:
- iso: eng
month: '06'
oa: 1
oa_version: None
publication: Scientific Online Letters on the Atmosphere
publication_identifier:
  eissn:
  - 1349-6476
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
researchdata_availability: no
scopus_import: '1'
status: public
supplementarymaterial: yes
title: Multiscale aspects of an extreme precipitation event over Nepal in September
  2024
tmp:
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  legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
  name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
  short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 22
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...