Day 3 charan singh, imd, india, arrcc-carissa workshop

Presentation at ARRCC-CARISSA workshop 29 Jan 2019 to 31 Jan 2019

1. Recent extremely heavy precipitation
events over Western Himalayan region
Charan Singh, Scientist &
Chief Forecaster, IMD

2. Contrastingfeaturesassociatedwith2unusual
extremelyheavy(>244.5mmin24hours)rainfall
eventsoverWesternHimalayanregion.
1
st
:DuringonsetphaseofSWmonsoonfrom15-17
June2013overUttarakhandand2
nd
:during
withdrawalphaseofSWmonsoonduring2-5Sept.
2014overJammu&Kashmir.
Boththeeventshavecausedextensivefloodsdue
to3-4dayslongspellofheavyrainfall.
Resultedhugedamagetohousing,infrastructure
andlargenumberlossoflife.
DISCUSSION ABOUT

3. WesternHimalayanregion(WHR)experiencesfairly
widespreadrainfallwithonsetofsouthwestmonsoondueto
interactionwithwesterlies&monsoonalwinds(easterlies).
In2013SWmonsoonwasonsetoverUttarakhandon16June,
normallyitonsetsoverUttarakhandinthelastweekofJune.
SW-monsoononsetoverKeralaon1June(normalonsetdate);
itfurtherrapidlyadvancedoverthecountryandcoveredentire
countryaboutamonthahead.
Heavyrainfalleventasaresultofalowpressurearea,
westerlytroughandmoistureincursionfromBOBaswellas
fromARBseaoverWHRparticularlyoverUttarakhand.
Duringonsetphaseofmonsoon,Uttarakhandexperienced
exceptionallyheavyrainfallduring15-18June,2013.
SYNOPSIS (Extreme rainfall event from 15-17 June 2013 over Uttarakhand)

4. ONSET OF SOUTHWEST MONSOON AND CUMULATIVE
RAINFALL OVER UTTRAKHAND
(15June)Dunda-8,Jakholi&kashipu-7eachandDehradun-5;(16June)Dehradun-22,Purola-17,Devprayag-13,Uttarkashi-13and
Tehri-12;(17June)Dehradun-37,Mukteshwar-24,Hardwar-22andUttarkashi-21and(18June)Haldwani-28,Champawat-22,
Haldwani-28,Nainital-17andRanikhet-12cm.
Onsetofmonsoonwasitsnormalonsetdate&coveredentirecountryaboutamonthaheadof
normaldate.
Therearetwopeaksinareaweightedcumulativerainfall(AWCR);oneovernorthwestandanother
oversouth-southeastofKedarnathAWCR>60cmand50cm.

5. 16 June W.D. over north Pakistan and adjoining J&K Low Pressure area
over East Rajasthan and Neighbourhood
WD, LOPAR, EASTERLY WINDS OVER GANGETIC PLAINS AND DENSE
CLOUDS MASS OVER UTTARAKHAND ON 16 JUNE, 2013
WD over north
Pakistan and
adjoining J&K
LOPAR over
East Raj. & nhd
850 hPa
500hPa

6. DYNAMIC PARAMETERS ON 16 JUNE, 2013
850 mb vorticity Lower level Convergence
Upper level divergence Upper level winds

7. IMD GFS (T574) Analysis wind on 16 June, 2013

8. 17 JUNE 2013 SYNOPTIC CHARTS
M.S.L. Pressure 925 hPa winds
500 hPa winds
500 -850 mb Deep Layer Mean 150-350 mb Divergence

9. 18 JUNE 2013 SYNOPTIC CHARTS
M.S.L. Pressure 925 hPa winds 500 hPa winds
500-850 mb Deep Layer Mean 150 to 350 mb Divergence

10. GFS(T574) ANALYSIS WIND ON 18 JUNE, 2013
INTERACTION OF
EASTERLY AND WESTERLY

11. VALUES OF DYNAMIC PARAMETERS ON 18 JUNE, 2013
850 mb vorticity Lower level Convergence
Upper level divergence
Upper level winds

12. DWR of Patiala dBzimages
(a) at 06:00:26 UTC of 16
Juneand
(b) at 03: 00: 26 UTC of 17
June,
Shows intense convection
north of Kedarnath over
Uttarakhand
Tropicalrainmeasuring
mission(TRMM)images
showsthaton14June
rainfallwasless,therainfall
areasaswellintensity
increaseson15Juneand
continuedoveralargearea
withpeakaroundKedarnath
(30.7
0
N/79.1
0
E)on16,it
decreases around
Kedarnathandareaof
higher rainfallshifted
towardssoutheaston17
June,2013
14 June
15 June
16 June
17 June

13. AWCR(mm)versesridgepositionat200hPalevel
along75.0
0
Elong.during10-20June,2013.
AWCR(mm)versesDivergencebetween150-300
hPalevelduring10-20June,2013.
AWCR(mm)ofUttarakhandversesOutgoinglong
waveradiation(w/m
2
)during10-20June,2013.

14. RelativehumidityoveraroundKedarnath(30.7
0
N/79.1
0
E)at
700,500and300hPalevelsduring10-20June,2013.
AWCR(mm)ofUttarakhandversesPrecipitable
watercontentsduring10to20June,2013.

15. Thefavourableconditionsforextremelyheavyrainfall:
TibetanHighmuchwestofitsnormalposition,deepwesterlytrough
between65
0
to70
0
E,lowpressureareaovereastRajasthanandmoisture
incursionfromBOBandARBoverWHRparticularlyoverUttarakhand.
OLRwasvariable,about190during15-17and220(w/m
2
)on18June.
Perceptiblewatercontentson10June:about23g/m
2
onandon16June:
about34g/m
2
.
Upperleveldivergancemorethan15X10
-5
s
-1
&Lowlevelconvergence
20X10
-5
s
-1
during15-18June.
Moisturefluxon10June:about180,15June:250andon16June:500
gm/kg.
Duetomoistureincursionovertheregionrelativehumidityincreased
from10onwardsanditwas90%during15-18June.
TRMMimageindicatesthattherainfallwasoftheorderof40-80mm/day
on14Juneand120-160mm/dayon15and16Juneoverlargeareaof
Uttarakhand.
SUMMARY OF 1
ST
EVENT

16. 2
nd
events (Extreme heavy rainfall event from 2-5 Sept. 2014 over Jammu & Kashmir)

17. 02-09-14
H

19. 03-09-14
H

21. 04-09-14
H
04-09-14/ Divergence
04-09-14/Convergence

23. 05-09-14
H
05-09-14/Convergence

25. 500 hPa Omega composite mean
Uttrakhand heavy
rainfall event
Jammu & Kashmir
heavy rainfall event

26. 500 hPa Relative Humidity composite mean
Uttrakhand heavy
rainfall event
Jammu & Kashmir
heavy rainfall event

27. 700 hPa Relative Humidity composite mean
Uttrakhand heavy
rainfall event
Jammu & Kashmir
heavy rainfall event

28. 500 hPa Air Temperature composite mean
Uttrakhand heavy
rainfall event
Jammu & Kashmir
heavy rainfall event

29. 400 hPa GPH composite mean
Uttrakhand heavy
rainfall event
Jammu & Kashmir
heavy rainfall event

30. 200 hPa GPH composite mean
Uttrakhand heavy
rainfall event
Jammu & Kashmir
heavy rainfall event

32. TherewasaWDinformofCC/troughinmid-tropospheric
level,whichremainedpracticallystationaryoverAfghanistan
andadjoiningnorthPakistanfrom2-5September,2014due
topresenceofintenseTH,whichwaswestofitsnormal
position.
Duringthisperiod,therewasthreemoresynopticsystem
viz.(i)LPAoverSaurashtra&neighbourhood.
(ii)WMLovercentral&northwestIndiaand
(iii)CCovernorthBayofBengal.
Asresult,averyhighmoisturefeedovertheregionwas
fromArabianSeaincomparetoBayofBengal.
Summary of 2
nd
event

33. Verification of All India SW Monsoon 2018 heavy
rainfall [24(D1), 48(D2), 72(D3), 96(D4) & 120 hrs(D5)]

34. Southwest Monsoon heavy rainfall
scores for D1(2002-18), D2(2010-18) and D3(2013-18)
Significant
improvement in skill
scores mainly
occurred in last two
years.
The increase rate in
D3 warning is much
higher than D1

35. Southwest Monsoon heavy rainfall
scores for D1(2002-18), D2(2010-18) andD3(2013-18)

36. Synoptic condition & RF over some stations in
Mumbai (Maharashtra) during 22-27 July 2005

37. Rainfall over Maharashtra (Mumbai) and some of the ever
recorded heaviest rainfall over India (cm)
Cherrapunji156.516.06.1995
AminiDivi 116.806.06.2004
Cherrapunji103.614.06.1876
Cherrapunji99.7 12.07.1910
Kasauli(HP)99.5 28.06.1899
Mausynram 98.9 10.07.1952
Dharamapur
(Guj)
98.7 02.07.1941
Chrrrapunji98.5 13.09.1974
Mumbai 94.4 27.07.2005Amount Date
Mahbaleshwar 26 July 2005 43cm 44 cm 07 July 1977
Parbhani 27 July 2005 27 cm 40 cm 27 June 1914
Mumbai 27 July 2005 94 cm 57 cm 5 July 1974
Alibag 22 July 2005 19 cm 40 cm 23 sept 1949
Bhira 26 July 2005 28 cm 43 cm 29 July 1967
Ratnagiri 22 July 2005 14cm 31cm 30 June 1953
Devgad 22 July 2005 20cm 47cm 19 June 1971
Harnai 25 July 2005 15cm 35cm 9 Aug 1974
Vengurla 25 July 2005 18cm 33cm 28 June 1958
MAHARASTRA
Highest Rainfall Recorded in
Climatological Normals 1951-1980
RainfallDateStation

38. Abreaksituationcould
bringinveryheavy/
extremelyheavyrainfall
alongthefoothillsofthe
Himalayas
Extremelyheavyrainsover
Assam&Meghalaya

39. 39
Thanks