Flood Watch for Northern and Central New Jersey

At this point, it appears as though this heavy rainfall threat will have to be monitored from a radar standpoint. The computer model guidance continues to shift the axis of heavy rain around with every model run. It is now returning to the solution of having the core of heavy rain over Pennsylvania and Northwest New Jersey. Refer to the earlier posts to compare the latest model images below with earlier runs.

I have now included future precipitation which shows that the region will get at least one and one half inches of rain, with less southeast and more northwest. The flood watch has been posted for much of Northern and Central New Jersey and this is where future precipitation indicates the best potential for two to three inches of rain over a widespread area. The model guidance is blended in to future radar from this morning. The big question south and east of Trenton will probably be if thunderstorms develop and if they produce localized heavy rainfall.

I think everyone is vulnerable to poor drainage flooding, street flooding, and ditches overflowing. Areas in the flood watch will be most vulnerable to stream and creek flooding. Certainly if Northeastern Pennsylvania and Northwestern New Jersey see heavy rainfall, that water will move downstream on the Delaware River and combine with heavy downpours around Trenton to cause large rises on the Delaware. The worst case scenario with this particular solution would result in a rise to near or slightly above the capacity. Should more than three inches fall (more liquid to work with), then we would have to watch for more significant flooding on both the Delaware and Raritan.

The bottom line is that hydroplaning and road closures appear quite possible Sunday Night and Monday across New Jersey with the greater chances the more north and west one lives or travels. Less rain may fall towards Cape May and this is where we have sandier soil anyhow.

I’ll have more on the wind and any potential severe weather (since we may be on the right side of the surface low) tonight.