As a weak AS-1 slips out of the off shore trough, the Northern end of the trough takes on a sudden strength. We had expected the trough to remain intact no doubt, but, it is getting good moisture at the Northern end (read Mumbai), and the result is over- active convection. Huge thundercell bang on Mumbai. (See wundermap).
A heavy thunderstorm on Saturday afternoon and evening resulted in S'Cruz receiving 72 mms and Colaba 22 mms till 5.30 pm.
AS-1 however is still very weak.
In a surprise move, IMD has plunged the SWM into Maharashtra right up to Alibag and eastwards into Pune. I have calculated the advance up to Goa, and interior Karnataka. But, that's ok now, the gap is narrow. The main parameters defcient according to me, SW winds are in place (though not strong enough ), and 200 jet stream is still aligning itself, and OLR would need a northward climb. Scientists at IMD are more experienced and equipped better.
Convective pre monsoon rains in coastal Maharashtra and interiors were heavy on Friday night.(See here for link). SWM could now move up , and land up at 20N sooner than expected.
TODAY'S WEATHER ACROSS AMERICA By Mark Vogan
Scorching Heat to Continue across South, Houston records earliest 100 in over hundred years yesterday!...check Mark's Blog for details.