2001 Islamabad cloud burst
|1999 Islamabad Cloudburst|
|Date of Occurrence||23 July 1999|
|Place||Islamabad, Rawalpindi, Hazara and Malakand Divisions|
|Maximum Precipitation||620 millimetres (24 in), in Islamabad|
On 23 July 2001, Islamabad experienced a record breaking 620 millimetres (24 in) of rainfall, which was the 24 hours heaviest rainfall in Pakistan during the past 100 years. Continuous downpour lasted for about 10 hours from 0600 to 1600 PST in Islamabad and Rawalpindi, caused the worst ever Flash flood in the local stream called Nulla Lai and its tributaries of Rawalpindi, which not only flood the low-lying areas of the twin cities but swept away the banks of the stream and buildings built in the encroachments. Islamabad's twin city, Rawalpindi experienced 335 millimetres (13.2 in) of rain during this event.
The cloud burst was the result of the sequel of vigorously developed cloud due to the combined effect of well marked westerly trough (Westerly wave), passing over 500hpa with enough supply of moisture from southwest monsoon.
A surface low pressure formed over Hazara and Malakand division between 34-37ºN and 70-75ºE with central pressure less than 996 hpa. There was a gradually accentuating upper air westerly trough at 500 hpa between 40-50ºN and 60-70ºE and there were strong monsoon incursions from the Arabian Sea and the Bay of Bengal while the southwesterly monsoon current from the Arabian Sea showed strong convergence over Islamabad, Rawalpindi District and Hazara and Malakand Divisions and the presence of a strong southeasterly monsoon current from along the foothills of the Himalayas caused the cloudburst over the twin cities of Rawalpindi/Islamabad.
|Name of Station||Location||0500–0800 PST||0800–1100 PST||1100–1400 PST||1400–1700 PST||Total Rainfall from 0500 to 1700 PST|
|PMD Headquarters||Islamabad||42 millimetres (1.7 in)||132 millimetres (5.2 in)||400 millimetres (16 in)||46 millimetres (1.8 in)||620 millimetres (24 in)|
|Saidpur||Islamabad||103 millimetres (4.1 in)||Did not measure||Did not measure||314 millimetres (12.4 in)||417 millimetres (16.4 in)|
|Shamsabad||Rawalpindi||04 millimetres (0.16 in)||83 millimetres (3.3 in)||200 millimetres (7.9 in)||48 millimetres (1.9 in)||335 millimetres (13.2 in)|
|Airport||Rawalpindi||Traces||06 millimetres (0.24 in)||65 millimetres (2.6 in)||99 millimetres (3.9 in)||170 millimetres (6.7 in)|
Pakistan Meteorological Department issued heavy rainfall forecast in its Weather Broadcast Bulletin a day earlier and Flash flood Warning was issued almost 4–5 hours in advance. Due to the continuous heavy downpour, the Nullah Lai and its tributaries over flooded and inundated the nearby houses, bridges and roads. According to the official figures, at least 10 people died, 800 houses were destroyed and 1,069 houses were damaged in Islamabad. Over all 61 people died of the catastrophe.
- "Severe Storms on dated 23 July 1999 Islamabad, Pakistan" (PDF). Abdul Hameed, Director Pakistan Meteorological Department.
- "Weather Log - July 21–31, 1999". National Climatic Data Center. 6 August 1999.
- Azmat Hayat, Anjum Bari Farooqi (5 July 2005). "ECONOMIC AND SOCIETAL IMPACTS OF VERY SHORT RANGE FORECASTING IN DEVELOPING COUNTRIES AND USER CONCERNS; PAKISTAN PERSPECTIVE" (PDF). Retrieved 2014-06-01.
- Naeem Shah (21 October 2002). "Cloud Burst (Heavy Rain) Over Twin Cities Islamabad - Rawalpindi on 23rd July 1999" (PDF). Retrieved 2014-06-01.
- Abdul Hameed (10 July 2007). "SEVERE STORMS on dated 23rd July 2001 Islamabad pakistan" (PDF). Retrieved 2014-06-01.
- "SMRC-Newsletter". Newsletter. SAARC Meteorological Research Centre. 8 (1): 7. July–December 2001. Archived from the original on 2003-09-30. Retrieved 2014-06-22.
- "SMRC-Newsletter". Newsletter. SAARC Meteorological Research Centre. 8 (1): 8. July–December 2001. Archived from the original on 2004-07-16. Retrieved 2014-06-22.