Monsoon axis after shifting towards far south due to the presence of a strong Arabian sea weather system (it has dissipated) is expected to return to the northern parts.
Second Monsoon Spell
Watch for flash and urban flooding in the coming week | Significant rain cannot be ruled out!
Two significant circulations can form in the coming days, one over NW India near New Delhi and other over KPK & adjoining northern Punjab. The Indian circulation will be sending moisture (strong easterlies) to its counter-part in Pakistan. The circulation in upper Pakistan can move from West to East due to westerlies.
Probability at 85% – Under the influence of both these weather systems, widespread rain with heavy to very heavy rain (some areas can experience extremely heavy rain) in Islamabad, northern & NE Punjab, central & adjoining south KPK and Azad Kashmir (Islamabad, Rawalpindi, Muzaffarabad, Jhelum, Sialkot, Gujranwala, Chakwal, Mianwali, Sargodha, Dera Ismail Khan, Peshawar, Lahore and adjoining cities do fall under these areas) from July 19 till July 21 (-1/+1 day error).
Scattered to widespread thunderstorms with heavy to chances of very heavy rain can also affect central Punjab (Faisalabad and adjoining cities) during this period.
Probability at 55% – Isolated to scattered thunderstorms with chances of heavy rain can affect south Punjab as well.
Few stray thunderclouds (probability at 35%) can also cross into upper Sindh during mid of coming week. Chances of drizzle/sharp showers in Karachi.
Third Monsoon Spell
A fresh low pressure is expected to form in the Bay of Bengal around the mid of coming week. Its track is uncertain currently. Some (chances at 35 to 40%) isolated to scattered thunderstorms can form over SE Sindh during the end of the coming week. Similar intensity to the 2nd monsoon spell (3rd monsoon spell) can hit upper Pakistan during the last week of July, currently its probability of materializing is at 50%. Chances of drizzle/sharp showers in Karachi.
Evaluation of July 5 update (1st Monsoon spell in the country)
|As mentioned on June 20 (upgraded on June 25) by PWP, the 2nd week of July has a very high possibility (70% to 75%) of monsoon onset. Due to the similar runs by GFS and ECMWF, for the first time this year ‘strong’ easterlies will penetrate NE Punjab and and adjoining upper Pakistan (KPK and Azad Kashmir) by the end of 2nd week and widespread heavy thunderstorms can be nearby these areas by July 10 to July 13/July 14 (+2, -1 day error).Given such scenario, the Portal upgrades monsoon hitting Karachi ‘around’ the third week (July 10 to July 17) of July from 45% to 58%.||Correct. Monsoon onset in NE Punjab, upper Pakistan and Karachi has happened as per the timeframe given by The Portal in its July 5 update. NE Punjab and upper Pakistan (July 10 to July 13/July 14 (+2, -1 day error).|
Correct. Karachi (July 10 to July 17)
|Hit or miss chances are from July 10 to July 13/July 14 (+2, -1 day error) in Sindh.||Correct as sporadic (on-and-off) downpours did occur during this time frame, they were not widespread, falling in the category of hit-or-miss.|
Wrong, we didn’t talk about the Arabian sea system (initially Rajasthan circulation) on our July 5 update. Because we didn’t think that it will become a stronger monsoon system. It was mentioned on July 13.
|Around and Post July 14, Low pressure (Bay of Bengal) can be nearby Sindh which can cause scattered to widespread rain in Sindh including Karachi.||Correct as scattered to widespread rains did occur mainly after July 14 (you can check the radar pics on our Twitter and Facebook page to see the spread of thunderstorms).|
Neutral as Low pressure of Bay of Bengal had weakened significantly due to the unexpected strengthening of Arabian sea system, although we never predicted that it will hit Sindh, our forecast maintained that it will be ‘nearby’. Bay System dissipated near Mahastrara and Madya Pradesh and adjoining Gujarat in India.