Momentum Within Meditation
Yes. 'Momentum' requires a succession of non-distracted states. 'Momentum' is a product of purification &amp; samadhi. 

Dry vipassana itself will not result in momentum because dry vipassana uses 'noting' or 'mental labeling', which are essentially 'distractions' or 'speed bumps'. It is only when the mind 'lets go' that 'momentum' will develop.

It is like letting go of a boat to flow down a river. Dry vipassana keeps the boat attached to the bank.

That said, dry vipassana is useful for developing 'sampajanna' ('clear comprehension'; 'applied wisdom'), which is a very important factor for samadhi development. 

'Sampajanna' is necessary for negotiating speed-bumps but, naturally, when a speed bump is experienced, this results in a loss of momentum, however temporary. 

The scriptures describe four kinds of meditative results (AN 4.41), the 3rd being the development of sati-sampajanna, for which dry vipassana is helpful.