Friday, April 26, 2013

Subsequent to writing the MW-2, a major and unexpected development disturbed our Monsoon Progress in the Sub-Continent. A sudden dipping of the 200 hpa jet streams, a sort of a "Rossby Wave" meandering, created an upper air trough from Pakistan through Kutch and Gujarat and dipped into Northern Maharashtra. The trough, versus the  normal position 8 days ago is shown here.(Map)

Its narrow isobars made an air "parcel" rise up, and the Lifted Index in the region showed a negative 6 figure.
The reason I call it as an upset is because the resultant thundershowers were widespread in NW Sub-Continent, Gujarat, North Maharashtra and, simultaneously, our friend,WD (A-5) moves in and interacts with this trough.
The shading indicates outgoing long wave radiation (OLR; W/m²). The contours show 200-hPa stream function at intervals of 5x106 m²/s.(2 maps)

Again, snow and rains in the Northern hills.
As a result, and expectedly, the day temperatures fell, and the seasonal low was almost wiped out.

To add to the commotion, an "unfriendly" Low, and associated UAC formed over Oman, bringing good rains and cooler weather from Oman to coastal Balochistan. The very regions where the seasonal Low is supposed to spread its wings into later.


Detailed Monsoon Watch (3) put up on Vagaries..With current position of Monsoon Progress..

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