Upton's thoughts.
CAMs depict the showers expanding in coverage later today as a weak frontal wave develops along the boundary, with the moisture slug gradually sinking south tonight. Much of the souther half of our area, including NE NJ, NYC, and Long Island, may remain predominantly dry through the afternoon, with the bulk of any showers over the Lower Hudson Valley and southern Connecticut. While an embedded thunderstorm or two cannot be ruled out, withlittle instability and weak shear, not too concerned about a severe thunderstorm threat. The abundant available moisture
however, PWATs climbing to around 2 inches per BUFKIT soundings,along with the potential for training, brings the threat of torrential rainfall. After collaboration with neighbors, decided to hoist a flood watch for all zones running from this afternoon through Tuesday afternoon. RFC 1/3/6 hr guidance is fairly high over southern Connecticut and the Hudson Valley
(where highest QPF lies). So while confidence isn`t particularly high given the longer duration of the event, along with expected rainfall rates generally under a half inch, short range ensembles are signaling the potential for heavy rainfall, particularly tonight into the first half of Tuesday, that could lead to flooding of urban and poor drainage areas. WPC has a slight risk for excessive rainfall outlined for the entire region both today and Tuesday. It should be noted that given the
low water levels from the dry antecedent conditions, larger rivers and streams should be able to hold the rainfall without
going into flood.