000 FXUS61 KOKX 071210 AFDOKX Area Forecast Discussion National Weather Service New York NY && .
NEAR TERM /UNTIL 6 PM THIS EVENING/... Several factors, the latest trends in radar, high res models, and 06Z guidance all pointing toward the axis of heaviest rain across the Lower Hudson Valley and interior southern CT, That being the case, have shifted the axis north of the coast, but still forecasting 1-2 inches region-wide. Ingredients are coming together for several hours of moderate to heavy rainfall across the area this morning. An upper trough emerging from the Ohio Valley will aid the development of a frontal wave that will pass in close proximity to Long Island this morning, and then east of New England this evening. The combination of deep-layered moisture and lift will allow for moderate to heavy banded rainfall along and just north of the low track. Additionally, mesoscale bands of localized heavy rainfall are possible with several inches of rainfall and flash flooding of urban/poor drainage areas. The axis of heaviest rainfall at this time appears to be shifting north of the coast, where the best frontogenetic forcing exists. This may allow for a widespread moderate to heavy showers across these areas, while stronger convective elements may be present closer to the coast due to better instability. However, the severe weather threat is low. While LCLs are low in this environment, the best low-level shear will likely be just south with the front and the instability is only marginal. The rain exits the area by early afternoon across far eastern locations, with the potential for some late afternoon/early evening showers/isolated thunderstorms across the interior due to weak instability and differential heating across the hills north and west of NYC. && .