April 19, 2012: Heavy Rain Finally To Return

Forecast Highlights:


- Rain and thunderstorms expected on Saturday afternoon/evening
- Heavy rain, wind possible with coastal low on Sunday, Monday
- Below average temperatures expected for weekend, early week


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After yesterday's unexpected light rain, cloud cover cleared today with mostly to partly sunny skies observed. Temperatures were warmer as well, peaking in the upper 60s to mid 70s from NYC and further north/west and the upper 50s to mid 60s in Long Island and southern CT. Similar temperatures are expected again tomorrow and on Saturday, although an approaching cold front will bring back rain into the forecast for Saturday afternoon/evening, which will be followed by a coastal storm which, if most of the latest models verify, should be the first significant rain event for the area since early December.


Tomorrow's Outlook:


Mostly to partly sunny skies are expected across the area again tomorrow with south/SSE winds keeping coastal areas colder again. Highs will reach the upper 60s to mid 70s from NYC and further north/west, and the upper 50s to mid 60s in Long Island and southern CT.


Saturday - Tuesday: Significant Rain Event Likely


A cold front will approach NYC on Saturday, with mostly cloudy skies becoming cloudy by the afternoon, along with a line of moderate to locally heavy rain and thunderstorms expected. At least 1/4 to 1/2 inch of rain is likely with the cold front. The front is then expected to move offshore and stall east of NYC, with some showers likely on Sunday along with cooler temperatures, peaking only in the 50s to possibly 60 degrees.

As the cold front moves through the area, a low pressure will develop near the southeastern US and begin to move up the coast. There is still some uncertainty with the exact track of the storm depending on how much phasing takes place, although the majority of the models show enough phasing to pull the storm north and NNW, resulting in at least moderate, if not heavy rain for NYC and further north/east. Yesterday, there was still uncertainty regarding whether the storm would completely phase and make it up the coast, although the GFS and NAM models, which were east of the area yesterday, are trending west and stronger with the storm to show more rain across the area. The rest of the foreign models, the ECM, CMC and UKMET, are in agreement with an overall wetter storm than the NAM/GFS but still differ with the phasing, as the ECM pulls the storm over NYC and into Michigan, while the CMC and UKMET take it north into Canada. These differences have more of an impact on the forecast for Monday and Tuesday, although these models still support moderate to heavy rain for the area.

Most of the rain from the coastal low is expected to fall on Sunday night, with windy conditions also possible depending on the track of the storm. As the storm moves to the north, scattered showers are expected on Monday along with cloudy skies and temperatures peaking in the lower to mid 50s across most of the area. Overall, at least 1 to 3 inches of rain are possible from the storm, with the highest amounts further east, towards Long Island and southern Connecticut. The forecast is still not final yet, however, as there is still uncertainty with parts of the forecast which could change the outcome. Stay tuned for more information on this storm and its impact in the NYC area.