The Watch Is On for the Next Typhoon

Jul 7, 2011; 12:24 PM ET

WIND SHEAR AT THIS TIME SEEMS TO BE KEEPING ON THE LID

A gathering of convective rain has slowly evolved in and about the Philippines this week. The area has slowly shifted northward such that is now centered near northern Luzon Island.

What is working against further organization towards tropical cyclone status is shearing upper-tropospheric winds from the east and northeast.

Japan Meteorological Agency satellite image shows tropical rain gathered off northern Philippines on July 7, 2011.

The latest GFS numerical forecast model (1200 UTC Thursday) shows slow lessening of the (unfavorable) wind shear over the next few days. It also shows the formation of significant low pressure beginning Sunday and Monday east of Taiwan and south of Okinawa.

Movement is forecast to be mostly towards the north as the low gathers together.

LATEST HIGHLIGHT ON THE SUBCONTINENT

Low pressure at the heart of the SW Monsoon circulation is shown by the GFS numerical forecast model to hover over the common area of Gujarat, Madhya Pradesh and Rajasthan for the next few days.

What is more, it is forecast to wring out very heavy falls of rain over a relatively small area during the weekend. Indeed, the “quantitative precipitation forecast” (QPF) of the 1200 UTC Thursday GFS has more than 37 inches (about 95 cm) with 24 hours (July 9-July 10)! The location forecast to have this much rain is 24 degrees North and 75 degrees East, with would be near Mandsaur, M.P.

I do not recall having ever seen this forecast model “show” so much rain in so short a time. I must also say that this is “cyber-weather”, NOT an actual forecast. QPF is notoriously unreliable, especially in relation to convective rainfall.

Still, the point is well-taken that a part of western and northwestern India will be at risk of flooding downpours towards the end of the week.