I think the answer is a qualified yes by late Sunday into Monday, but I’m not anticipating a major impact .
Isaac’s long journey through drought-plagued Arkansas and Missouri will squeeze out a good portion of its abundant tropical moisture before any of its effects can be felt in Washington.
Of course, Isaac has a large moisture field - so the decay of its center matters little in evaluating how and when pieces of it might feed into D.C..
It seems that the critical feature in determining Isaac’s effect on our area is a weak “back door” cold front sliding south from the Northeast. This front - initially moisture-deprived - is likely to stall over the mid-Atlantic beginning Saturday.
As such we have a chance of intermittent showers and storms starting Sunday afternoon and continuing into Monday. Locally heavy downpours are possible.
I don’t expect a widespread deluge or a prolonged period of rain. And if the front sets up far enough south, it might rain hardly at all or any rain we get would result from Atlantic moisture not Isaac’s remnants.
This forecast is one which requires fine-tuning, so please check back for daily updates.