RMetS Saturday meeting 8 February 2014:
Understanding the weather of 2013
The Indian monsoon summer of
2013
Andy Turner
Images sourced from BBC News
Outline

Importance of the monsoon to India

What is a monsoon? Normal conditions

Progression of the onset: what and why

Parallels with the Pakistan floods of 2010

Remainder of the season and return to normal

Cyclone Phailin: double whammy of monsoon and
tropical cyclones together?

Summary
Introduction – importance of the
monsoon to South Asia
Indian daily rainfall 2002
• 80% of India’s rainfall during
summer monsoon.
• Agriculture is are strongly tied
to monsoon timing, intensity &
duration.
• Monsoon drought can
damage economy: e.g. 3%
loss of GDP in 2002 (Challinor
et al., 2006).
(source: BBC News)
Graphs from Monsoon On-Line www.tropmet.res.in/~kolli/MOL
Introduction – importance of the
monsoon to South Asia
Indian daily rainfall 2009
Indian daily rainfall 2002
rainfall accumulation 2009
(source: BBC News)
Graphs from Monsoon On-Line www.tropmet.res.in/~kolli/MOL
Introduction – importance of the
monsoon to South Asia
mean rainfall (June to September)
~850mm
(averaged over “all-India”)
Year-to-year
standard deviation:
~84mm
Graph from Monsoon On-Line www.tropmet.res.in/~kolli/MOL
Flooding as a cause of death in India
“Territory size shows the proportion of
all people who have died in disasters
due to floods, 1975-2000.”
From www.worldmapper.org, based on UN/FAO data
Some background
What is a monsoon?
Land/Sea Temperature contrasts
Nov/Dec
West African Monsoon Asian Monsoon
May/Jun
Austral Monsoon
Seasonal 925hPa wind changes and
monsoons
DJF
West African Monsoon
JJA
Asian Monsoon
Austral Monsoon
Seasonal daily precipitation changes and
monsoons
DJF
West African Monsoon
JJA
Asian Monsoon
Austral Monsoon
Typical onset progression of the
monsoon
From IMD
July 1
June 15
July 15
June 5
June 10
July 1
June 1
June 15
June 10
June 5
June 1
• Typically 1 June
(monsoon onset over
Kerala)
• Standard deviation
of around 7 days
Monsoon 2013
Progression of the onset and the
northern India floods
Rainfall accumulation and anomalies
from onset to mid-June
df
Charts from Climate Prediction Center/NCEP
Rainfall locations & anomalies during
the northern India flooding
dfg
Charts from Climate Prediction Center/NCEP
Onset and rainfall accumulation
Rain accumulation
Daily rain totals
Apr
Slide courtesy
Climate Prediction
Center/NOAA
May
Rain accumulation
Rain accumulation
Daily rain totals
Daily rain totals
Apr
May
Jun
Apr
May
Jun
Jun
Onset and rainfall accumulation
Charts from India Meteorological Department
Onset and rainfall accumulation
SW monsoon covered the
entire country on 16 June 2013
Charts from India Meteorological Department
Anomalous flow during the onset
dsfgsd
Charts from Climate
Prediction
Center/NCEP;
graph from
IPRC/UH monsoon
monitoring page
Monsoon 2013
Parallels with the Pakistan floods
of 2010
Similarity with Pakistan floods of 2010
Rain anomaly 26 July 2010
Rain anomaly 10-16 June 2013
Charts from Climate Prediction Center/NCEP, and CMORPH precipitation
12 Jul – 10 Aug 2010 low-level wind anomaly
9 – 15 Jun 2013 low-level wind anomaly
Similarity with Pakistan floods of 2010
Upper level flow July 2010
Upper level flow June 2013
Charts from Climate Prediction Center/NCEP and University of
Reading archive of ECMWF analysis
H
L
14-21 June 2013 upper level streamfunction
L
23-30 July 2010 upper level streamfunction
2013 seasonal rainfall total
Seasonal rainfall total: 925mm
(870mm normal) +6.3%
Indian daily rainfall 2013
rainfall accumulation 2013
Charts from IMD; graphs from Monsoon On-Line
Cyclone Phailin, 8-14 October 2013

VSCS PHAILIN is the most intense cyclone that reached
India after Odisha Super Cyclone of October 1999.

At landfall on 12th Oct, maximum sustained surface wind
speed was ~115knots (215km/h); estimated central
pressure of 940hPa; pressure drop of 66hPa compared to
surroundings.

Maximum rainfall occurred northeast of the system centre
at landfall, up to 38cm accumulating in 24hr in parts of
Odisha.

Estimated maximum storm surge of 2-2.5m above tide;
inundation of salt water up to 1km from the coast.
Information from India Meteorological Department
Forecast lead time
IMD accurately predicted
the genesis, intensity, track
and landfall and associated
adverse weather 4 to 5
days in advance.
From IMD/Joint Typhoon Warning Center
Seasonal dependence and track
Can tropical cyclones and
monsoons hit India together?
Average daily rainfall in India
Comparison of monsoon
rainfall through the year with
average cyclone counts
suggests not.
Tropical cyclone formation is
dependent on high seasurface temperatures during
summer, but the strong wind
shear during the monsoon
tends to destroy them
quickly.
From Claire
Bartholomew
Average cyclones/month in N Indian Ocean
Summary

Most rapid monsoon onset in more than 80 years,
bringing three times normal rainfall for early June &
flooding northern states of India.

Despite a few days’ warning, difficult terrain and
infrastructure damage, combined with pilgrimage mean
100,000 pilgrims/tourists were trapped, of the thousands
of casualties: 95% were in Uttarakhand, nearly 6000
presumed dead.

Worst tropical cyclone to hit India since 1999:

1999 Cyclone Paradip had 3-minute sustained winds of
260km/h, made 1.7 million homeless and killed nearly 10,000.

Cyclone Phailin 3-minute sustained winds of 215km/h, thought
to have killed ~60.
Summary

Proof of the good forecast and contingency planning in
a World Bank comment,
“This has taken years of planning, construction of
disaster risk mitigation infrastructure, setting up of
evacuation protocols, identification of potential safe
buildings and most importantly, working with
communities and local organisations in setting up
volunteer teams who all knew exactly what needed to
be done”.
The end
Thank you for your attention!
[email protected]
Monsoon clouds: Marcel Costa
(distributed via imaggeo.egu.eu)