UNDERSTANDING EXTREME WEATHER

M MOHAPATRA

INDIA METEOROLOGICAL DEPARTMENT

NEW DELHI-110003

m. mohapatra@imd.gov.in

Presentation layout

Introduction

Extreme Weather Monitoring and Forecasting

Present Day Status,

Gap and Way Aheads

Conclusions

Most of the natural hazards

are weather related

WINTER

(JAN-FEB)

PRE-MONSOON

(MAR-MAY

MONSOON

(JUN-SEP)

POST-MONSOON

(OCT-DEC)

WESTERN DISTURBANCES COLD WAVE, FOG

CYCLONIC DISTURBANCES

HEAT WAVE

THUNDER STORMS, SQUALLS

HAIL STORM

TORNADO

SOUTHWEST MONSOON CIRCULATION

MONSOON DISTURBANCES

NORTHEAST MONSOON

CYCLONIC DISTURBANCES

Major Natural Disasters and risk management in India

Risk management

Hazard Analysis and statistics

Vulnerability Analysis

Preparedness and Planning

Early Warning System

Prevention and Mitigation

Early Warning Components

Obserbation, Monitoring and

analysis and Prediction

Warning generation

Warning dissemination

Public education and Outreach

Verification of warning

• India Meteorological Department : All Meteorological hazards

• Central Water Commission : Floods,

• Geological Survey of India : Landslides

• Indian National Centre for Ocean Information Services : Tsunami

Meteorological Information from IMD is used in several ways for

Disaster Risk Reduction in the region.

Hazard Monitoring, Early warning and Mitigation.

Technical support in risk assessment, preparedness & planning,

Management of natural resources from disasters (Agriculture/Water

resources, Health, Energy Resources etc)

Hazard Monitoring and Forecast Process

Action

Runs of different Models,

Consecutive runs from the same model,

Ensemble runs ("choosing the best member")

Numericalforecasts

ModelDecisionmaker

Numericalforecasts

Endforecast

Initial conditions (Observations)

ForecasterModel

Model runs

Numericalforecasts

Broad Classification of

Observations

Surface

Upper Air

Space Based

• Pilot Balloon

• RSRW

• Profiler

• Ground Based RADAR

• Aircraft

• Geoststionary Satellites

• Polar Orbiting Satellites

• AWS

• ARG

• SYNOP

• BUOYS

• AVIATION

• SHIPS

Monitoring and

Forecast Process

Nowcasting for next 3-6 hours(Venue/ location specific)

Short Range for next 72 hours (Location/District/Met Sub-division)

Medium Range for next 3-7 days(District)

Extended range for 10-15 days (Met Subdivision/State)

Long range for month/season (Homogeneous regions/country)

Public Weather Local Forecast

Tropical Cyclone Forecast & Warnings

Warnings related to all other Disaster (heavy rain/snow, thunderstorm,

squall, hailstorm, strong wind, storm surge, heat/cold wave, fog etc)

Sea State and Coastal Zone Forecasts, Fishermen warning

Forecasts to Aviation

Forecasts for Agriculture

Customized Forecasts to different Sectors- Power, Tourism, Defense,

Adventure, Road/Railway transports, Public Utility, VIP functions,

Strategic operations, Space, event based etc

IMD’s Forecast & Warning

North Region

Central Region

South Region

West Region

East Region

North East Region

Regional CentresDelhi, Kolkata, Guwahati, Nagpur, Mumbai, Chennai

Pune Centre for Research /Training and surface instrumentation

National Weather

Forecasting Centre

at New Delhi

Meteorological Centres1. Srinagar

2. Chandigarh

3. Shimla

4. Dehra Dun

5. Lucknow

6. Patna

7. Itanagar

8. Jaipur

9. Ranchi

10. Agartatala

11. Ahmedabad

12. Bhopal

13. Raipur

14. Bhuvaneshwar

15. Hyderabad

16. Bangalore

17. Thiruvananthapuram

18. Panjim

19. Gangtok

Cyclone Warning Four stage cyclone warning

(Pre-cyclone watch, cyclone

alert, cyclone warning, post-

landfall outlook )

Sea area bulletin

Coastal weather bulletin

Bulletins for Indian navy

Fisheries warnings

Port warnings

Aviation warning

Bulletins for departmental

exchanges

Bulletins for AIR/

Doordarshan/ press

DTH bulletins

Warnings for registered

users.

Cyclone warning system

Example of graphical presentation of cyclone warning

Thunderstorm:

• Moderate Thunderstorm

Loud peals of thunder with frequent

lightning flashes, moderate to heavy

rains and maximum wind speed 29 to 74

kmph

• Severe Thunderstorm :

Continuous thunder and lightning,

heavy rains and maximum wind speed ≥

75 kmph

Hailstorm and Squall

Frequency of Hailstorms in

100 years period • Slight Hailstorm :

Sparse, usually small size and

often mixed with rain

• Moderate Hailstorm :

Fall abundant enough to

whiten ground

• Heavy Hailstorm :

Includes at least a proportion

of large stones

SQUALL:

A sudden increase of

wind speed by at least 29

kmph(16 kts), the speed rising

to 40 kmph (22 kts) or more

and lasting for at least one

minute

Moderate : Surface wind

speed ( in gusts) upto 80 kmph

Severe : Surface wind

speed ( in gusts) > 80 kmph

Tornado and waterspout

Nowcasting of thunderstorms

Nowcasting.

Location specific forecast for severe

weather for planning of aviation

activities, sport events and high risk

operations.

15

Heat wave & Thundersquall warning (25 May, 2015)

Heat wave (5.0 to

6.00C above

normal)

Thunder

squall at

isolated

places

>22

kts

Severe heat

wave

( 7.00 C above

Normal or

station reported

45.00 C or more)

Thunder

squall at

a few

places

>22

kts

and

abo

ve

Severe heat

wave

( 7.00 C above

Normal or

station reported

45.00 C or more)

at wide area

Severe

Thunder

squall at

many

places

>22

kts

and

abo

ve

No warning No

warning

Nil

16

Cold wave/ visibility & ground frost warning,

(11 January, 2015)

Cold wave

(5.0 to 6.00C

below

normal)

Ground

frost at one

or two

places

Visibility

at one or

two places

< 500 M

Severe cold

wave ( 70 C

below

normal)

Ground

frost at a

few places

Visibility

at a

few/many

places

<200 M

Cold day

( day temp.

<150C) or

severe cold

wave

Ground

frost at

many

places

Visibility

at most

places

<50 M

No warning No warning No warning

17

Fog/visibility warning (17 January, 2015)

Visibility at

one or two

places

<500M

Visibility at a

few/many

places

<200 M

Visibility at

most places

<200 M

or less

than <50

M

No Warning Nil

18

Heavy snow & hail storm warning

(12 January, 2015)

Very heavy

snow at

one or two

to many

places

>65

cm

Ths + hail+Squall

Heavy

snow at a

few places

>35

cm

Ths+hail+ squall

Heavy

snow at

one or two

places

>35

cm

Ths+ squall

No

warning

Nil

Flood Warning: Basic Structure

.

Streamflow Forecasts

Hydrological ModelHydrological

Observations

Meteorological

Observations

Weather Forecasts

Weather Forecast Models

IMD

CWC

Flood

Warnings

FLOOD WARNING• Real time Hydro-meteorological observations

• Real-time communication and modeling.

• Decision support system for issuing quantitative

precipitation forecast (QPF) and heavy rainfall

warning in place

• Heavy rainfall forecast is still a challenge

Heavy rain at

isolated places

>6.5 cm

or more

Heavy to very

heavy at

isolated/ few

places

>12.5

cm or

more

Heavy to very

heavy at a few

places or

isolated

extreme heavy

>12.5

cm or

more

No warning Nil

• Onset, spread, intensification and

cessation of drought (near real-time

basis) on a daily, weekly, monthly and

seasonal time scale over the country

(RF departures, Aridity Anomaly Index,

SPI).

• Weekly Drought Outlook, based on this

index, which indicates the impending

drought scenario in the country in the

subsequent week.

Drought Monitoring and Forecasting

GAPS AND WAY AHEADGaps

• Inadequate observations used to initialize the weather and climate

models,

• Need for improved simulation of key processes and the interactions

between these processes,

• Last mile connectivity.

Way ahead

• Augmentation of observational network

• Numerical models with much finer horizontal and vertical grid

resolution.

• coupled Ocean-atmosphere, high-resolution models

• Ensemble modeling systems (thus providing probability forecast

information)

• Last mile connectivity

Thank you