Government of Nepal Ministry of Energy, Water Resources and Irrigation D epartment of Hydrology and Meteorology Nagpokhari, Kathmandu, Nepal. PRELIMINARY WEATHER SUMMARY OF NEPAL April 2018 MAIN HIGHLIGHT Most parts of the country recorded normal to above normal rainfall and normal to below normal temperature (Fig.2, Fig.4, and Table 2) SYNOPTIC SEQUENCES Two cyclonic circulation one over Jharkhand and adjoining Gangetic West Bengal (3rd -11th April) between 2.1 and 5.8km with trough extending from the circulation to Assam, Bihar, Chhattisgarh and second over Punjab and adjoining Pakistan (4th – 8th April) along with western disturbances as upper air troughs influenced weather during 1st and 2nd week of the month. Rainfall during the 3rd week was associated with cyclonic circulation over Pakistan and adjoining south west Rajasthan (14th - 18th April) and a trough running from this system to Madhya Pradesh. Cyclonic circulation over sub Himalayan West Bengal and adjoining West Assam up to 1.5km (20th April -2nd May) also affected weather during 4th week and last 3 days of the month. PRECIPITATION DISTRIBUTION Most parts of the country received rainfall greater than 25.0mm with pocket areas over province 4, province 2 and province 1 receiving rainfall greater than 180mm. Northern parts of the country received below normal rainfall whereas rest of the country received normal to above normal rainfall. Biratnagar Airport received the highest 24 hour rainfall of 65.0mm on 11th April 2018 also recorded the highest total rainfall of 251.9mm and highest percentage of rainfall 474.4% (Figure 1, Table 2). TEMPERATURE PATTERN The mean temperature varied between less than 12.0°C in the northern parts of Province 4 and 6 to above 27.0°C around the southern border of province 2, 5 and 7 (Figure 3). Except for eastern corner of province 1, northern limit of province 4 and adjoining areas of province 6 and 7 rest of the country recorded normal to below normal temperature. Lowest anomaly of -1.6°C was recorded in Thakmarpha whereas the highest positive anomaly of 1.4°C was recorded over Jumla (Fig.4, Table 2). Bhairahawa Airport recorded the highest maximum temperature of 40.0°C on 21th April while Thakmarpha recorded the lowest minimum temperature of 1.0°C on 8th April (Table 2). Fig.1: Total Precipitation (mm) 30 April 2018 Dadeldhura Jumla Dipayal 29 Dhangadhi Jomsom Surkhet Lumle Nepalgunj Dang Pokhara 28 Kathmandu Jiri Bhairahawa Okhaldhunga Taplejung Simara 27 Dhankuta Dharan Janakpur Biratnagar 25 50 75 100 125 150 180 230 Fig.2: Percentage of Normal Precipitation(%) 30 April 2018 Dadeldhura Jumla Dipayal 29 Dhangadhi Jomsom Surkhet Lumle Nepalgunj Dang Pokhara 28 Kathmandu Jiri Bhairahawa Okhaldhunga Taplejung Simara 27 Dhankuta Dharan Janakpur 0 30 60 90 110 150 250 350 450 Biratnagar Fig.3: MeanTemperature(°C) 30 April 2018 Dadeldhura Jumla Dipayal 29 Dhangadhi Jomsom Surkhet Lumle Nepalgunj Dang Pokhara 28 Kathmandu Jiri Bhairahawa Okhaldhunga Taplejung Simara 27 Dhankuta Dharan Janakpur 12 15 18 23 27 Biratnagar Fig.4:Departure of Mean Temperature from 30 Normal(°C) April 2018 Province 6 Dadeldhura Jumla Dipayal Province 4 29 Dhangadhi Jomsom Surkhet Province 3 Lumle Province 7 Province 1 Nepalgunj Dang Pokhara 28 Kathmandu Jiri Bhairahawa Province 5 Okhaldhunga Taplejung Simara 27 Dhankuta Dharan Janakpur Province 2 -1.2 -0.4 -0.2 0.2 0.8 1.3 Biratnagar 80 81 82 83 84 85 86 87 88 Remarks: Normal Rainfall (Gray colour) = 100 ± 10 % Normal Temperature (Gray colour) = 0 ± 0.2 °C Table: 2 PRELIMINARY MONTHLY WEATHER DATA April 2018 PRECIPITATION TEMPERATURE No. of Rainy Days Maximum ( °C ) Minimum ( °C ) Mean ( °C ) Stations >30°C & Date& normal normal normal Total(mm) %of Normal mm 1.0 ≥ ≥ 10.0 mm 10.0 ≥ mm 25.0 ≥ mm 50.0 ≥ No.ofwith Days Average Min Average Average Max Average MonthlyMean 24hrs Extreme Rainfall Extreme 24hrs LowestDate&Min HighestDate& Max Departure from Departure the from Departure the from Departure the minimumtemperature DADELDHURA 48.7 88.4 7 2 0 0 14/7 24.4 0.79 28.6/27 12.5 0.1 9.1/13 18.4 0.5 0 DARCHULA 54.2 79.8 8 2 0 0 15/3 30.7 -0.2 34.5/22 15.5 1.6 11.6/13 23.1 0.7 21 DHANGADHI 56.3 238.7 5 2 1 0 27/11 35.1 -0.8 38.5/25 18.9 1.3 16/14 27.0 0.2 29 DIPAYAL 61.3 156.9 8 2 0 0 16/10 33.9 -0.3 37.6/19 15.8 0.5 11/10 24.9 0.1 26 JUMLA 38.0 89.3 12 0 0 0 9/21 22.1 0.4 24.3/19 6.1 2.5 3/1 14.1 1.4 0 SURKHET 78.0 267.5 4 2 1 1 56/10 32.3 -0.5 34.9/17 16.8 0.2 13.5/14 24.6 -0.1 25 NEPALGUNJ AIRPORT 90.7 366.9 4 3 2 0 42.1/7 35.8 -0.2 38.6/27 19.9 1.5 15.2/23 27.8 0.6 30 CHAURJHARITAR 71.5 224.5 2 2 1 1 57/7 32.3 -1.0 36/22 14.5 -0.7 11.5/1 23.4 -0.8 27 GHORAI ( DANG ) 32.4 121.2 3 1 0 0 24/30 32.4 -0.4 35.4/21 18.2 1.1 15/14 25.3 0.3 28 JOMSOM 11.5 57.9 3 0 0 0 8.5/21 18.1 -0.7 21/13 6.0 1.7 4/27 12.0 0.5 0 THAKMARPHA 18.1 60.6 3 1 0 0 12/21 17.0 -0.9 20/1 2.5 -2.3 1/8 9.7 -1.6 0 TANSEN 102.8 322.8 7 3 1 1 53.5/30 27.9 -0.9 31.5/22 15.9 0.0 8.8/5 21.9 -0.5 6 BHAIRHAWA AIRPORT 54.9 207.8 5 2 0 0 22/30 35.3 -0.8 40/21 20.2 0.3 16/14 27.8 -0.2 30 KHANCHIKOT 92.0 245.4 6 3 2 0 31.1/5 22.8 -0.1 26/30 13.8 -0.4 10/1 18.3 -0.2 0 POKHARA AIRPORT 199.3 156.1 16 7 3 0 29/18 29.0 -0.8 31.6/2 16.7 1.0 13.8/14 22.9 0.1 9 LUMLE 155.6 140.2 15 5 1 0 33/5 21.2 -1.5 24/21 12.5 -0.1 10/13 16.9 -0.8 0 RAMPUR 50.0 84.3 4 2 1 0 33.6/18 34.5 -1.2 37.2/22 18.9 0.7 14.4/24 26.7 -0.2 29 SIMARA AIRPORT 41.2 81.7 5 1 1 0 27/30 34.3 -0.6 37.4/22 19.6 0.6 15.2/14 27.0 0.0 29 KATHMANDU AIRPORT 126.7 207.7 11 3 2 1 51/3 26.8 -1.4 30.2/22 13.2 1.6 10.5/28 20.0 0.1 3 PANCHKHAL 80.3 188.7 10 2 1 0 25.4/3 30.0 -0.9 34/21 14.0 0.6 9/25 22.0 -0.2 15 DHUNIBESI 43.1 84.5 11 0 0 0 9.8/17 30.0 -0.5 32.7/24 16.6 -0.4 14/12 23.3 -0.4 20 JIRI 94.0 102.0 15 3 0 0 20.6/28 21.3 -0.9 26/21 8.3 1.6 4/1 14.8 0.4 0 JANAKPUR AIRPORT 113.7 217.8 6 4 1 1 53.8/30 33.9 -1.0 37.4/22 21.4 0.8 17.5/1 27.6 -0.1 24 JALESORE 97.4 328.9 5 2 1 1 60/30 34.5 -0.6 37.5/17 21.5 0.2 18.8/6 28.0 -0.2 29 KABRE 78.7 120.7 11 3 0 0 15.7/20 24.0 -1.2 27/17 12.2 0.1 9.5/1 18.1 -0.5 0 OKHALDHUNGA 121.2 203.5 11 3 2 0 34/30 24.3 0.5 36.2/4 12.8 -1.1 10.5/9 18.6 -0.3 1 LAHAN 201.5 435.0 9 6 2 2 59.5/5 32.5 -1.3 35.5/3 21.2 0.2 18/1 26.9 -0.6 27 RAJBIRAJ 124.4 276.4 8 4 2 0 46.5/5 31.4 -3.6 34.5/3 22.6 1.7 18.5/29 27.0 -1.0 25 DHANKUTA 102.5 221.4 10 5 1 0 25/30 25.9 -0.3 29.4/2 15.8 0.0 13/1 20.8 -0.2 0 DHARAN 66.1 89.7 9 1 1 0 26.9/9 32.2 -0.8 35.2/3 21.8 0.7 18.4/9 27.0 0.0 27 BIRATNAGAR AIRPORT 251.9 474.4 10 8 4 1 65/11 31.8 -2.1 35.5/3 20.8 0.4 17.7/1 26.3 -0.8 25 TARAHARA 82.6 125.1 9 3 1 0 25.2/30 32.7 -0.4 36.2/3 19.4 0.2 14/1 26.0 -0.1 26 KHADBARI 59.1 91.8 10 2 0 0 22.2/28 26.7 -1.2 30.1/2 16.5 -0.5 13.5/1 21.6 -0.9 3 TAPLEJUNG 105.6 70.0 13 3 0 0 21/21 22.6 0.3 25.5/2 12.0 0.0 0/12 17.3 0.1 0 KANKAI 68.7 105.0 8 3 0 0 20.5/10 31.9 -1.6 35.5/2 19.5 0.4 15.5/1 25.7 -0.6 25 Remarks: Rainfall recorded on a day is the total 24 hour rainfall from the previous day 8:45 am till 8:45 am of that day.