Lok Sabha Question No. 2067 (UNSTARRED), answered on 2019-11-29
Subject: Winter Forecast by IMD
Ministry: EARTH SCIENCES
Asked by: Bidyut Baran Mahato, Prataprao  Jadhav, Gajanan Chandrakant Kirtikar, Sudheer Gupta, Sanjay Sadashivrao Mandlik

## MINISTRY OF EARTH SCIENCES

## GOVERNMENT OF INDIA LOK SABHA

## UNSTARRED QUESTION No. 2067

TO BE ANSWERED ON FRIDAY, NOVEMBER 29, 2019

## WINTER FORECAST BY IMD

2067.  SHRI BIDYUT BARAN MAHATO:

SHRI PRATAPRAO JADHAV:

SHRI GAJANAN KIRTIKAR:

SHRI SUDHEER GUPTA:

SHRI SANJAY SADASHIV RAO MANDLIK:

Will the Minister of EARTH SCIENCES be pleased to state:

- (a) whether the India Meteorological Department (IMD) proposes to issue a winter forecast and cold wave alerts for current winter season, if so, the details thereof;
- (b) whether the Meteorological Department has also predicted the fog conditions in the country;
- (c) if so, the details thereof, State/ UT-wise;
- (d) if  not,  the  reasons  for  the  delay,  along  with  the  accuracy  rate achieved by the IMD in making predictions during each of the last three years; and
- (e) the  steps  taken/being  taken  by  the  Government  to  increase  the efficiency and accuracy rate in this regard?

## ANSWER MINISTER FOR MINISTRY OF SCIENCE AND TECHNOLOGY AND MINISTRY OF EARTH SCIENCES (DR. HARSH VARDHAN)

- (a) Yes  Sir,  as  per  practice,  India  Meteorological  Department  will  be issuing  the  seasonal  temperature  outlook  for  the  current  winter season and it will be released by the end of November 2019.

In addition to seasonal outlook, IMD also issues weekly cold wave alerts and warnings once in every week valid for next 4 weeks. These forecasts are made available through IMD, Delhi website (www.imd.gov.in)

- (b)&(c) The National Weather Forecasting Centre, IMD, New Delhi issues five days forecast and warnings in sub-division scale. These forecasts are updated four times a day and serve as a guidance bulletin for the State/Regional Meteorological offices. The State/Regional Meteorological  offices  in  turn  issue  forecast  and  warnings  in  the district level. IMD monitors & issues forecasts and warnings for the

occurrence of fog along with its intensity as and when required and these warnings are included in the daily weather bulletins.

- (d) The verification of fog forecast for the last four seasons is given in Annexure.
- (e) From 2016-2017, IMD started a Forecast Demonstration Project (FDP) for  winter weather systems and the same is conducted during the period  from  1 st   December  to  28  February.  It  takes  care  of  the prediction of weather associated with winter weather systems like rainfall/ snowfall, fog, cold wave and ground frost.

It  is  an  integrated  national  campaign  including  IMD  and  other institutes like National Centre for Medium Range Weather Forecasting  (NCMRWF),  Indian  Institute  of  Tropical  Meteorology (IITM), Indian Air Force (IAF), Space Application Centre (SAC), etc. The various units of IMD like National Weather Forecasting Centre (NWFC) and the Satellite Meteorological division of IMD headquarters, Regional Weather Forecasting Centres and State Weather Forecasting Centres, Met. Watch offices and Aviation Meteorological offices  under  RMC  New  Delhi,  RMC  Kolkata  &  RMC  Guwahati participate in this campaign. Based upon the inputs from all, NWFC, IMD, New Delhi issues a daily guidance bulletin for winter weather systems which include current observations, details of past weather, synoptic  features,  thermodynamic  &  dynamic  features  from  NWP models with summary and conclusions beneficial for monitoring & prediction. Significant improvement in prediction of winter weather systems including fog had been observed after the commencement of FDP.

In an effort to gain insight into the occurrence of fog, the Ministry of Earth Sciences (MoES), Government of India has taken up a multiinstitutional initiative Winter Fog Experiment (WIFEX) to conduct an intensive ground based measurement campaign at the India Gandhi International  Airport  (IGIA),  Delhi,  to  understand  different  physical and chemical features of fog and factors responsible for its genesis, intensity and duration. WIFEX was conducted in a pilot mode at IGIA during  winter  season  2015-16  and  is  being  continued  during  the period from December to February in the following years. The main scientific objective of this project is to study the characteristics and variability of fog events and associated dynamics, thermodynamics and fog micro physics, with the aim to achieve better understanding of fog life cycle and ultimately improve capability in fog prediction. In addition to Indian Institute of Tropical Meteorology (IITM), Pune, IMD, Centre  for  Medium  Range  Weather  Forecasting  (NCMRWF),  Airport Authority  of  India,  GMR,  IGIA  and  Indian  Institute  of  Science

Education and Research (IISER) Mohali and also participating in this observational campaign.

## Annexure

Verification of Fog forecast (All India) for the last four seasons:

| All India   | FAR   | FAR   | FAR   | MR   | MR   | MR   | CSI   | CSI   | CSI   | POD   | POD   | POD   |
|-------------|-------|-------|-------|------|------|------|-------|-------|-------|-------|-------|-------|
| All India   | D1    | D2    | D3    | D1   | D2   | D3   | D1    | D2    | D3    | D1    | D2    | D3    |
| 2018-19     | .05   | .04   | .04   | .62  | .72  | .86  | .22   | .17   | .09   | .38   | .28   | .14   |
| 2017-18     | 0.15  | 0.17  | 0.13  | 0.16 | 0.24 | 0.36 | 0.64  | 0.57  | 0.51  | 0.84  | 0.76  | 0.64  |
| 2016-17     | 0.12  | 0.12  | 0.06  | 0.39 | 0.52 | 0.72 | 0.47  | 0.36  | 0.24  | 0.61  | 0.48  | 0.28  |
| 2015-16     | 0.18  | 0.17  | 0.05  | 0.50 | 0.57 | 0.87 | 0.33  | 0.3   | 0.11  | 0.50  | 0.43  | 0.13  |

FAR - False Alarm Rate; MR - Missing Rate; CSI - Critical Success Index; POD - Probability of Detection (%)

Average error of fog forecasting for 2015-19

| Lead Time of warning issued   |   FAR |   MR |   CSI |   POD |
|-------------------------------|-------|------|-------|-------|
| 24 hours                      |  0.05 | 0.42 |  0.4  |  0.58 |
| 48 hours                      |  0.05 | 0.51 |  0.34 |  0.49 |
| 72hours                       |  0.03 | 0.7  |  0.24 |  0.3  |

-  In General, large scale dense fog was predicted 3 to 5 days in advance.
-  Attempt was also made to provide the timing of intense fog spell.
-  Provided  information  to  various  users  including  Indian  Railway  and Medical Association.
-  During  2018-19,  there  was  very  less  occurrence  of  prolonged  spells  of dense fog. Most of dense fog episodes were for 2-3 hours only.