So much rain fell at Reagan National Airport last evening that the eventual 1.64 inch total eclipsed all others this calendar year. It was, in fact, the wettest day since way back on December 7, 2011 when the airport tallied 3.10 inches.  The very high moisture content of the air, fueled by the leading edge of Isaac and rainfalls like last night's, will make it very difficult for the dew points to drop during the next few days.  Combined with a stalled front to our south and southerly winds, there is a high likelihood of more thunderstorms and heavy downpours at least through Tuesday.  And while daytime highs should remain in the 80s, the high humidity will produce heat indice around 90. 

Some relief from the mugginess could arrive with a front on Thursday.  By pushing the damp air to the east, that frontal passage could make Friday and Saturday the kinds of days we wish we were having this Labor Day weekend - mostly sunny, cooler and dry!  Keep your umbrella handy as your continue to enjoy the remainder of your holiday.