GOES web site and created an animation for the period Monday 17.15hrs on Feb 21 to 02.15 the next morning. It will play once - refresh to play again. If it does not play then click it.
The red and white show where heavy rain is likely to be occurring. Heavy rain was falling much of Monday in Georgetown.
Notice that the clouds do not come in off the Atlantic but form over Guyana. This make forecasting difficult.
Our Hydromet office here uses the same source for their forecast page.