Mar 6, 2011 Storm Updates

Below, storm updates will be posted on the storm that will affect the area with widespread heavy rain. Three alerts are currently in effect for the area, a Rain Warning, a Heavy Rain Warning, and a Freezing Rain Alert.


8:50 PM: Heavy Rain Begins To End

Over the last 1-2 hours, a line of heavy rain began moving through the area, and winds have also increased, in some places gusting over 40 mph. The heaviest rain moved through northern New Jersey and is currently over the immediate NYC area. Over the next several hours, the heavy rain will continue to shift east, moving through parts of Long Island and Connecticut that have failed to see any significant amounts of rain yet.

The rain will begin to weaken in the western parts of the area within the next 1 to 2 hours, and within the next 1 to 3 hours for the immediate NYC area. Occasional showers will continue afterwards, and heavy rain currently near Washington DC may move into the area later tonight. As the storm ends, especially after 12 AM, precipitation will begin to change over to freezing rain for the interior parts of the area, especially in Sussex and Orange counties, and will mix afterwards with sleet and potentially snow. Accumulations will not be significant, however the potential is there for up to 0.1 inch of freezing rain and 1/2 inch of snow/sleet, therefore I issued a Freezing Rain Alert for the interior parts of the area. The entire area will be dry by the morning.

The next update will be posted tomorrow, discussing in more details the heavy rain potential for Thursday and Friday as well as another potential storm around March 15.


3:45 PM: Heavy Rain Approaches

After a brief break in the steady rain earlier this afternoon, widespread rain has resumed over the last hour, with the heaviest rain falling west of New York City. The storm’s heaviest rainfall is currently located from eastern Virginia into Pennsylvania and is slowly shifting to the east.

The latest NAM model showed the heaviest rainfall right over northern New Jersey, with a little more than 3 inches of rain, however its hour 3 and hour 6 composite reflectivity is off when compared to the latest radar, therefore I did not use it for the total precipitation forecast. It still appears that the heaviest rain will fall to the west of New York City, however a general 2 to 3 inches of rain are expected north and west of New York City, locally up to 3.5 inches especially further northwest, with 1 to 2 inches further east, locally up to 2.5 inches, therefore I upgraded the Heavy Rain Watch to a warning.

As the storm ends, precipitation is expected to change over to light snow, sleet and freezing rain especially for Sussex and Orange counties. Any frozen precipitation, however, should be light and will likely amount to less than 1/2 inch of snow/sleet and less than 0.1 inch of freezing rain.

More updates will be posted later tonight as the heavy rain moves towards the area.


12:00 PM: Increased Rain Totals

Since last night’s update, the models have shifted slightly east with the storm track, bringing a much wetter scenario especially for the western parts of the area. Looking at the latest observations, however, this morning’s models seem to have a better handle on the storm than last night’s models. As a result, I placed the entire area under a Rain Warning and re-issued a Heavy Rain Watch for the western parts of the area.

This morning, the area has been seeing an area of rain move through with light to moderate rain. The steady rain is expected to end within the next 1 to 2 hours, with more occasional showers expected to continue until the late afternoon. From there, however, as the storm moves towards New York City, heavy rain will begin to move into the area. Despite the heaviest rain falling towards central/eastern Pennsylvania and northeast of there, a general 1.75 to 2.5 inches of rain are still expected for parts of the area that are north and west of NYC, with 1 to 2 inches south and east of there.

The heaviest rain will fall in the evening and early overnight hours, and will begin to end after 2 AM. As the storm ends, light snow, sleet and freezing rain will likely mix with the rain in the northwestern parts of the area, especially in Sussex and Orange counties, however any accumulations should be light and will stay below 1/2 inch of snow and sleet. Dry conditions will return by Monday morning.

More updates will be posted on this storm throughout the afternoon, as well as updates on Thursday’s storm, which the latest trends are suggesting may move very slowly, if not stall, bringing the potential for widespread heavy rain and flooding to parts of the region including the area.

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