South-West Monsoon is expected to ‘Onset’ by late June between 28 June – 30 June in Lower Sindh including Karachi
The Tropical Easterlies has started retreating from Sindh region and would subside from Lower Sindh by 25th June making the dominance of the Tropical Easterlies ( TEJ / Monsoon Winds ) over Western Jets.
The Tropical Easterlies would start ‘slightly’ influencing the region from 26th June onward making 60% chances of ‘full dominance’ from late 27th June (+1/2 day error) in Lower Sindh!
Monsoonal System and Its Influence:
The certain conditions of Jets would put forward the formation of possible Upper Air Circulation (UAC) based in entire Sindh on 28th June producing the anticipated ‘First Monsoonal Thunderstorms’ for Lower Sindh including #Karachi from 28 June onward. Some reliable models are predicting 15+/- mm meaningful rainfall in Karachi in last days of June [ Overall Chances of Formation of UAC aren’t Certain OR Chances are 45% – 50% ].
On the same time, the Bay of Bengal (BOB) would produce its first monsoonal circulation in troposphere near Kolkata on late 27 June which would continue marching in the direction of WNW; reaching Lalitpur region of Madhya Pradesh ( Central India ) by late 28th June while constantly intensifying into Low Pressure Area (LPA) and then expected to transform into Well-Marked Low Pressure Area on 29th June. The evolution of Low Pressure into Well-Marked Low Pressure is highly possible.
Later on after 29th June LPA lying over Western-Madhya Pradesh is expected to move either in the direction of NW towards Southern Punjab through Rajasthan or in the direction of W / SW towards Sindh through Gujrat-Rajasthan. However the chances of moving into Sindh are greater than Punjab (i.e: 30% – 45%) on current scenario but it can also dissipate or “weaken” before reaching Pakistan.
If the LPA remains strengthen with reliable conditions then it would start influencing Sindh from early 30 June onward until its annihilation and would pour meaningful accumulated Rains with earth-shaking Thunder and Dust-storms. Isolated Thunderstorm are expected to form.
Since the onset date announced and chances of formation of Thundercloud in Lower Sindh between 28th June – 30th June (+1 day error) are assured / confirmed with favourable set-up direction for Karachi, Hyderabad, Mirpurkhas, Thatta, Badin, Thar and their vicinity (Chances: 45% – 55%) but however later-on if there is alteration in certain conditions which led towards the distraction of LPA or weakening of LPA can also put Pakweather.com to recast its prediction.