Low remains off the Odisha coast..almost same strength at 1000 mb..expected to merge with the UAC in the same region...
The jet streams are now almost fully Westerly up to almost 25N...currently 100 hPa , has its core is along Lat. 13°N with wind speed higher than 60 knots. During the week, the highest wind speed of 75 kts was recorded over Thiruvananthpuram at 150 & 146 hPa on 16th September.
Today, we also see a trough in the Westerlies in the North Pakistan region. That is why I mentioned yesterday a speedy withdrawal in NW India expected soon.
The Low in the Bay remains off the Odisha coast.
I would not like to comment now, but unofficially can say the Myanmar anti cyclone at 500 hpa ( Necessary for NEM advance winds).can be expected around the 10th of October...it needs certain parameters to form over the Bay to get started.
A 1 hour rainfall recorded 31 mms from 9 pm IST at Vagaries on Friday Night..
Posted Thursday Night ( 18th September):
South West Monsoon is in the withdrawal process, and has withdrawn from West Rajasthan. A ridge formation, an anticyclone in the 200 hpa level, and surface winds from the NW bringing a sharp reduction in humidity ensures speedy withdrawal from Rajasthan, Kutch, Punjab, HP and Kashmir by Saturday 20th September.
Delhi NCR would see gusty NW winds from Saturday through Sunday. Warming up the day and sliding the night temperatures to around 23/24c.
Weekend will see hot days with day temperatures peaking at 43/44c in the Sindh region of Pakistan.
Days get hotter in Rajasthan and Kutch.
Friday/Saturday and Sunday:
Contrary to this, rainfall may increase in West Bengal, with heavy falls. Odisha and AP continue to get the regular thunder showers. Increasing rains in Central and South interior Peninsula.
Mumbai City get a cloudy morning. clouds forming in the day. Shower expected by evening in parts of city.
Rains low till 23rd,after which we may see some increase.
Similarly with Pune, low rainfall this weekend, increasing to heavy thunder showers after 23rd.
Kolkata may get thunder showers in the afternoon/evening this weekend.
Hyderabad , may benefit from a low coming after the 22nd. Thunder showers on 22nd and 23rd.
Possible of a heavy thunder shower in Bangalore on Friday/Saturday.
Glance into Vagaries' Long Term Forecast (probable):
A Low forms off the AP coast around 23rd/24th September. Seeing the scenario today, it seems due to the anticyclone in the North (by then), this system may cross into AP/TN coast, and cross into Karnataka.
Thunder showers increase in the States of Maharashtra and Karnataka from 24th.
A slight chance, that this system may re emerge in the Arabian Sea around the 27th. Thunder showers continue in Maharashtra in that case.
A "strong" WD can be expected (seeing the trough possible in the North) around 26th/27th. If things work out well, the trough, and WD rains, can dip South till Central Sindh.
What do we wait ansd see ? What do we study in this case ? We have to monitor if a) the WD "pushes off" the Arabian Sea Low, or b) the system "pushes of" the WD.
In case of b), the system can move towards Gujarat.
These are Long Term probables, and I do not have definite answers to the outcome