Sept 29: Final Storm Forecast


There are currently two alerts in effect, a Heavy Rain Warning, and a High Wind Watch. For more details, read below, or read the appropriate alerts in the “Weather Alerts” page.

The 5-Day Forecast was not updated tonight.

Final Forecast:

The models are now coming into a consensus that the heavier rain amounts will likely affect the area. As a result, I have increased the forecast rain totals from yesterday’s forecast and kept them the same as those from earlier this afternoon.

Tropical Storm Nicole has dissipated, but a low pressure related to Nicole’s moisture will move up the East Coast, bringing heavy rain tomorrow. The heaviest rain from this round will likely fall towards western New Jersey and eastern Pennsylvania, with 3 to 5 inches possible during the day. The immediate NYC area will likely see 2 to 4 inches, with Long Island/S CT seeing 1-2 inches.

By Thursday night, as the first low pressure moves into New England, another low pressure could approach the area, bringing another round of heavy rain, but this time focusing further east than the first round of heavy rain, moving through the immediate NYC area and Long Island/S CT, bringing 2-3 inches of rain for those areas.

The rain will end by Friday morning. By the time that the storm ends, 4 to 7 inches of rain are possible for the interior and the immediate NYC area, with 3 to 5 inches of rain for Long Island/S CT. I put up a rain map above, with the model consensus and my thoughts put into it. The NAM/GFS/SREF are west of the model consensus, and while I did take them into consideration, I do not think the rain will be as far west as they show it to be. While I include the area in the 5+ inch area, not the entire 5+ inch area will see 5+ inches, but it is meant to show where the best chance of seeing over 5 inches of rain is.

Despite this, there is still some uncertainty, and it is possible that the heavy rain could end up slightly west of my forecast.

Winds: Strong wind gusts are also expected with this storm. As the eastern side of the storm typically brings strong winds, I placed Long Island/S CT and the immediate NYC area in a High Wind Watch. Sustained winds between 30 and 40 mph, with gusts as high as 55-60 mph are likely with this storm, which could cause damage along with the flooding. Some severe weather could also be possible with this, as SPC has placed the area under a slight risk of severe weather.

Overall Summary:

This will likely be the strongest storm to affect the area since the March nor’easters. Heavy rain with 4 to 8 inches and flooding will affect a large part of the Mid Atlantic and Northeast, with strong wind gusts up to 60 mph in the eastern parts of the storm also causing damage. This is not a storm to take lightly, and while the scenario could still change around a little, this storm could have a significant impact on the area.

Updates will be posted tomorrow afternoon while the storm is ongoing.

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