Mar 17, 2011: Winter To Return One More Time

***This post is from 2011. Please visit the MAIN PAGE to see the latest forecasts for the NYC area.

----------------------------------------------------------------------

As a high pressure moved into the Southeast today, temperatures quickly warmed up, reaching the 60s across most of the area with mostly sunny skies. The mild temperatures won't last long as a cold front on Saturday night brings back colder temperatures, with temperatures on Sunday morning below freezing across most of the area. Temperatures are expected to warm up on Monday and Tuesday as a storm moves to the north of the area, however afterwards, winter is expected to make one last comeback as a much colder air mass moves into the region for the late week and the weekend, and even snow may return to parts of the region one last time this winter.


Tomorrow's Outlook:

As a storm moves near southeastern Canada towards Maine tomorrow, it will draw in additional warm air, bringing the warmest temperatures to the area since October. High temperatures are expected to peak in the upper 60s to lower 70s for NYC and further west, with mid to upper 60s for the eastern parts of the area except for the coast, which should see temperatures in the lower 60s. Parts of the immediate NYC area could even reach the mid 70s.

The day will start out mostly cloudy with a southwest wind, however partly sunny skies are expected by the afternoon with a breezy WSW wind becoming west. Winds may gust up to 30-35 mph, especially in the eastern parts of the area.


Weekend Outlook: Dry, Chilly

Tomorrow night, as the cold front comes through, temperatures will drop into the mid 30s to lower 40s across the area, with lower to mid 40s in NYC. A high pressure will move towards the area on Saturday, resulting in clearing skies other than a few possible morning showers, and high temperatures will rise into the mid 40s to lower 50s across the area with a few mid 50s in the immediate NYC area.

The high pressure will move over the region, resulting in mainly clear skies for Saturday night. Low temperatures will be cold, dropping into the lower to upper 20s away from NYC, and in the lower 30s for New York City. Sunday will bring temperatures similar to those of Saturday.


Tuesday - Thursday: Winter To Appear One Last Time?

Cloud cover will increase on Monday morning as a storm approaches the area from the west. This low pressure is expected to move through Maine on Monday night, bringing some rain to the area with mild overnight temperatures potentially rising into the lower 50s in the immediate NYC area, with drier conditions returning by Tuesday afternoon and high temperatures likely in the upper 40s to mid 50s.

The exact details are still uncertain, but looking at the overall model scenarios, there is a general consensus that there will be a strong high pressure in southern Canada moving southeast. The storm will likely intensify as it moves through Maine and towards southeastern Canada, helping to pull in the cold air towards the region. Then uncertainty comes into the forecast with a low pressure that is expected to be near Kansas on Tuesday.

To the left, I posted an image from the 18z GFS run which can be found in this link. The green and blue areas represent precipitation, with green representing light precipitation and blue representing moderate-heavy precipitation. The southernmost blue line represents 850 mb temperatures at zero degrees celsius, north of that line it would typically be cold enough to support snow. This image shows a low pressure in southern Virginia, with precipitation falling in the form of snow in Pennsylvania and central/southern New Jersey.

When looking at the models, it is important to keep in mind that this is still several days away, and considering the model performance this month, it is likely that we will see at least some changes with the set up, but with the majority of the models showing similar scenarios and this storm already entering the medium range, there is the potential for snow to fall somewhere in the region from this storm. It is still possible that the models change back to a no snow scenario, however today's models are suggesting that there is a potential for snow to fall somewhere in the region.

As should be expected in the longer range, the exact solutions are different with each model. The GFS suppresses this snow risk to the south of the area, with the 12z GGEM brought a moderate to heavy snowfall to parts of the area. There is a wide range of possibilities with this storm, with snow potentilly falling to the south of the area, over the area, just north of the area or no snow at all, but with the set up currently suggested, it is unlikely that it snows well north of the area. For now, the snow potential is still low, however if future model runs continue to show similar scenarios, there may be a higher risk for snow to fall somewhere in the region. Stay tuned for more information on this potential storm and whether it may bring snow to the area or not.


Longer Range: Regardless of whether it snows or not, it is expected to get cold again after this storm. The GFS is still likely overdoing the cold air with high temperatures below freezing, but there is the potential for high temperatures to end up in the mid 30s to mid 40s after this storm. More information will be posted on the longer range as details become clearer.