Seasonal Forecasting at Pakistan Meteorological Department

Transcription

1 Seasonal Forecasting at Pakistan Meteorological Department by Zubair Ahmed Siddiqui Director R.M.C. Gilgit-Baltistan, Pakistan Meteorological Department

2 Area : 796,095 km2 Population: 180,440,005 Temp Range: -20 to +50oC All Geographical features ; 600 KMs long Coastal line, Five major Rivers, Vast Fertile Plains, Deserts, Plateaus, World s highest Mountain Ranges (HKKH), Glaciers, Largest canal system of irrigation in the world.

3 Pakistan Meteorological Department Meteorology (Weather Forecasting) Hydrology (Flood Forecasting) Seismology (Earthquake Monitoring)

4 Meteorological Phenomena / Weather Systems in Pakistan Southwest Monsoon in Summer Pre monsoon & Post monsoon Winter Monsoon / Western Disturbances 4

5 Resources, Tools, Methods & Techniques of Short Range (Daily) Forecasting & Long Range (Monsoon) Forecasting

6 Meteorological Observatories Network 70 Surface Observatories 12 PBO & RadioSonde 88 Rain Gauge Stations 56 Automatic Wx Station (AWS) 08 River Discharge Gauges 02 GLOF Stations 01 Air Quality Monitoring Stns.

7 Karachi Lahore Rwp / Isb Sialkot R.Y.Khan Multan Peshawar D.I.Khan Quetta Jiwani Pasni Khuzdar Gilgit Skardu Chitral Hyderabad Nawabshah Sukkur Jacobabad 19 Aviation Met Centres

8 Radars Network of PMD PMD has 07 Radars, 10 Cm Doppler Radars, QPM Radar 5 Cm Wx. Surveillance Radars which are in operation at different parts of Pakistan, are covering almost 80% area of Pakistan. 1- Lahore 2- Mangla 3- Sialkot 4- Islamabad 5- D.I.Khan 6- Rahim Yar Khan 7- Karachi Six new Radars are also under process.

9 Remote Sensing and Weather Satellites Geostationary Satellite of China (FY) NOAA-14 & NOAA-15 Polar Orbiting Satellites Geostationary Satellites of Japan, Europe and Russia

10 WEATHER & PRECIPITATION MONITORING USING THE EARTH SATELLITES PMD is maintaining satellite ground stations (HRPT, DVB, SADIS) at Islamabad, Quetta and Karachi.

11 Numerical Weather Prediction Facilities datasets in any format supported by WMO Formats High Speed Server CLUSTER GrADS data GRIB data NetCDF data etc.. performs analysis operations manages sessions, translates dataset names supports extended request types for analysis, upload Result cache internet holds temporary data (uploaded, generated by a previous operation, or transferred directly from another server) for use in remote analysis data and requests Encapsulated Analysis Requests client libraries data appears to client as local file, in a standard format (i.e, NetCDF, etc.) Client GrADS Matlab IDL etc..

12 Early Warning Systems of PMD National Weather Forecasting Centre Islamabad (NWFC) Marine Meteorology & Tropical Cyclone Early Warning Centre Karachi (TCWC) Flood Forecasting Division Lahore (FFD) Flood Forecasting & Warning Centre For Lai Nullah Basin Islamabad Drought/Environment Monitoring & Early Warning Centre Islamabad National Seismic Monitoring & Tsunami Early Warning Centre Karachi & Islamabad (NSMC)

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14 Monthly Distribution of Normal Annual Rainfall Mean monthly rainfall during July (63 mm) is highest and contributes about 21% of annual rainfall (298 mm). The mean rainfall during August & September are slightly lower and contributes about 19% & 7% respectively of annual rainfall 14

15 Annual Precipitation Trend ( ) 15

16 Annual Precipitation ( ) Area Weighted Departure y = 0.414x R² = Percentage Annual Linear (Annual ) 3 per. Mov. Avg. (Annual )

17 Pakistan s Summer Monsoon Rainfall The monsoon precipitation plays a very important role in the social and economic development of Pakistan. About 60 % of total Annual Rainfall over most parts of Pakistan is received during Summer Monsoon. 2010, 2011, 2012 & 2013 consecutively recorded above normal monsoon rainfall. 17

18 Monsoon (Jul-Sep) Normal Precipitation Gupis Gilgit Chilas Bunji Astore Skardu Chitral Drosh Dir Hill Station Saidu Sharif Plain Station Balakot Kakul GhariMuzaffarabad Dupatta PeshawarRisalpur Murree Cherat Islamabad Kotli Kohat Parachinar Jhelum Mianwali Sialkot Sargodha D.I.Khan Faisalabad Zhob Rafiqui Quetta Bhawalpur Kalat Khanpur Jacobabad Khuzdar Larkana Moenjodaro Panjgur Rohri Hyderabad Karachi 500 mm 400 mm 300 mm 150 mm Nawabshah Pasni 600 mm 200 mm Padidan Lasbella Jiwani 700 mm Bahawalnagar Barkhan Dalbandin 800 mm Multan Sibi Nokkundi Lahore Badin Chhor 100 mm 50 mm 0 mm 18

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20 Normal Tracks of Monsoon Waves and Westerly Waves in July Western Disturbance Monsoon Currents Monsoon does not penetrate much in Balochistan, GB and KPK

21 Pakistan s Monsoon Rainfall Highest rainfall 600mm over Kashmir, adjoining sub-mountain of Punjab & eastern KPK. Southern Punjab, Upper Sindh, most parts of Balochistan receive less than 100mm of rainfall. Driest part is northwestern parts of Balochistan and GB which 21 is not affected by monsoon.

22 Long Range Forecasts Monsoon Forecasts Multiple Linear Regression Models using certain regional & global predictors. Statistical Downscaling of GCMs - presently two GCMs NCC CGCM and NCEP models are being downscaled. Dynamical modeling - using different Global Climate models by using persisted Sea Surface Temperatures.

23 Long Range Forecasts Monsoon Forecasts Estimated seasonal amount of rainfall is being calculated on monthly and seasonal time scales by applying the statistical dynamical methods, using global, regional and local predictors. Output of the Combined General Circulation Model (CGCM) is used to obtain the predicted rainfall over the selected stations. It is prepared with a lead time of one month to three months. 23

24 Criteria of Terminologies The calculated percentage departure of the expected rainfall in Pakistan from the normal rainfall is classified as follows: Sr. No. Percentage departure of forecast rainfall from normal Classification used for describing the rainfall forecast 1 Above 50 % Largely above normal 2 26 % to 50 % Moderately above normal 3 11 % to 25 % Slightly above normal 4-10 % to +10 % Normal 5-11 % to -25 % Slightly below normal 6-26 % to -50 % Moderately below normal 7 Below -50 % Largely below normal 24

25 Summer Monsoon Rainfall 2016 (1 st July to 24 th September)

26 Summer Monsoon Rainfall 2016 (1 st July to 24 th September)

27 Summer Monsoon Rainfall ( ) (Percentage Departure from Normal) REGION NAWR (upto 24 th Sep) Whole Country mm 28% 30% 3% 8% -25% -1% 27 % Azad Kashmir mm 5% -10% -14% 6% 7% -25% -17 % Balochistan 58.3 mm -4% 30% 8% 22% -39% -46% -17 % Gilgit-Baltistan 41.6 mm 81% 2% 1% 10% 136% 12% 26 % Khyber-P.Kh mm 35% 5% -2% 13% -29% 12% 39 % Punjab mm 32% 26% 9% 10% -10% 23% 57 % Sindh mm 58% 158% 6% -21% -78% -19% 03 % 27

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30 WINTER (Jan-Mar) Normal Precipitation Gupis Gilgit Chilas Bunji Astore Skardu Chitral Drosh Dir Hill Station Saidu Sharif Plain Station Balakot Kakul GhariMuzaffarabad Dupatta Risalpur Peshawar Murree Cherat Islamabad Kotli Kohat Parachinar Jhelum Mianwali Sialkot Sargodha D.I.Khan Faisalabad Zhob 500 mm Rafiqui Quetta Multan Bahawalnagar Barkhan Sibi Dalbandin Nokkundi 400 mm Bhawalpur Kalat 300 mm Khanpur Jacobabad Khuzdar Larkana Moenjodaro Panjgur 200 mm Rohri 150 mm Padidan 100 mm Nawabshah Lasbella Jiwani Lahore Pasni Hyderabad Karachi Badin Chhor 50 mm 0 mm

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41 Winter (JFM) Seasonal Rainfall (% Departure) REGION 2014 % 2015 % 2016 % Pakistan Azad J&K Balochistan Gilgit-Baltistan Khyber-PK Punjab Sindh

42 Outlook for October 2016

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45 Outlook for November 2016

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48 Precipitation Forecast for Sep-Oct-Nov (SON), Outlook for the upcoming three months has been prepared after downscaling output of the Beijing Climate Centre, Climate System Model version 1.1 (BCC-CSM1.1) for our region. Above normal rainfall is predicted all over the country during the season (September November) except some extremely northern tips of the country where normal to slightly below normal rainfall is expected during the season. Northern parts of Punjab, Azad Jammu and Kashmir and adjoining areas of Khyber Pakhtoonkhwa are likely to get rainfall with maximum positive anomaly. Southern parts of Sindh and northern Baluchistan are also expected to get slightly above normal rainfall during the season September to November,

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51 for your attention