Mar 4: Two Heavy Rain Potentials

Note: With the uncertainty currently developing for Sunday’s storm, I updated the forecast, but did not type in a full discussion. Using tonight’s data, I am working on a more detailed discussion which will be posted late tomorrow morning after the rest of tonight’s model data comes in. For now, I updated the forecast for the immediate NYC area with my latest thoughts, which are explained in more details below.

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The cold air mass that was over the region yesterday left the region, bringing warmer temperatures along with it after cold morning temperatures, dropping again into the mid 10s for the interior parts of the area. High temperatures were generally in the upper 30s to lower 40s for most of the area, with mid 40s southwest of NYC and more widespread upper 30s for Long Island and southern Connecticut.

Temperatures will warm up even more tomorrow, peaking in the mid to even upper 50s in the immediate NYC area and further southwest, however as we have seen many times this winter, once again we are dealing with a lot of uncertainty for Sunday night’s storm, with potential rain totals ranging from 1/2 inch to as much as 3 inches of rain. Behind this storm, another storm late next week also has the potential to bring heavy rain into the area.

Tomorrow’s Outlook:

Tomorrow will continue with the mostly cloudy skies along with a south/SSE wind. High temperatures will peak in the upper 40s to lower 50s for most of the area, and lower to mid 50s in the immediate NYC area. Upper 50s are possible southwest of NYC.

Tomorrow night, low temperatures will remain steady in the lower to mid 40s across most of the area, and even though a few showers are possible, most of the rain will stay to the west of the area.

Sunday – Monday: Uncertainty Returns

Many times this winter, we have reached the point where we are two days away from the storm and there is a lot of uncertainty on what it will do, and unfortunately we have reached this point once again. The range of possibilities is a wide one, ranging from the ECMWF and GFS which take the storm through Long Island, with the heaviest rain totals falling over the Interstate 95 corridor with 2 to 3 inches in the western parts of the area, to the NAM and CMC which take the storm through the western Northeast, with the latest NAM run bringing the heaviest rain totals in Ohio with barely 3/4 inch for NYC and less than 1/2 inch for Long Island.

At this time, I went with a compromise track taking the storm a little closer to the ECMWF and GFS, with the storm taking a track over the area, which would bring the heaviest rain west of New York City. Rain totals may range from 1/2 to 2 inches for the eastern and central parts of the area, with 1.5 to 2.5 inches of rain west of New York City. In this scenario, the rain would begin falling in the early afternoon to the early evening hours from west to east, and intensify with the heaviest rain falling between the evening and overnight hours. As the storm exits the area, freezing rain may mix in the interior parts of the area, however at this time this risk is uncertain and it is possible that no freezing rain falls, or there could be more widespread freezing rain.

This track that I used, however, is still a moderate confidence one at best, and it is possible that the models may adjust to a further west solution, which may result in the removal of the Heavy Rain Watch and downgrading the Rain Warning to a Rain Watch. Stay tuned for a full update tomorrow in the late morning hours discussing this storm in more details, including scenario maps, and more details about the Thursday-Friday rain event.

Longer Range: More Rain On Thursday-Friday

With calm conditions expected from Monday afternoon through Wednesday, the next storm threat is not too long in the future, with more rain expected to return to the area on Thursday. For now, there is a decent agreement with the models that the storm will track west of the area, bringing a cold front through with heavy rain potentially between 1 and 3 inches. As we have seen with past storms, however, details with the storm have changed as we got into the shorter range, and while the smaller details are uncertain at this time, there remains a heavy rain threat for Thursday and Friday. Stay tuned for more information on this time frame as details become clearer.

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