Assuming a warm front is moving into the area, there is a stignant (non moving) cold air mass around New York, what type of precipitation might be expect? How long might it last?

To determine the type of precipitation and its duration when a warm front moves into an area with a stignant (non-moving) cold air mass around New York, we need to understand how these weather systems interact.

When a warm front approaches a stignant cold air mass, it typically rides up over the denser and colder air. This process brings the warmer air above the colder air, leading to the formation of clouds and precipitation.

The type of precipitation expected will primarily depend on the temperature profiles at different altitudes. As the warm air rises over the stationary cold air, it cools and condenses, resulting in the formation of various types of precipitation.

Here are a few possibilities:

1. Rain: If the warm air mass is significantly warmer than the cold air mass, with temperatures above freezing at all altitudes, rain is likely to occur. This would be the case if the colder air is close to the freezing mark or slightly below it.

2. Freezing Rain: In some cases, the warm front might bring in warm air aloft while the surface temperatures remain near or below freezing. As the precipitation falls through the shallow cold layer near the ground, it does not have enough time to freeze into ice pellets (sleet) or snowflakes. Instead, it freezes upon contact with the cold surface, forming a glaze of ice. This is known as freezing rain.

3. Snow/Sleet: If the warm front brings in a relatively colder air mass, and the temperatures at all altitudes are below freezing, the precipitation is likely to be snow or a mix of snow and sleet. The exact proportion of snow and sleet will depend on the vertical temperature profile.

The duration of the precipitation associated with a warm front can vary. It generally lasts longer than the passage of a cold front but shorter than a stationary front. Precipitation from the approach of a warm front can begin several hours before the front actually passes through, and can last for hours or even days, depending on the speed of the warm front and the associated weather system.

To get the most accurate and up-to-date information about the type and duration of precipitation during the warm front's interaction with the stagnant cold air mass around New York, it is best to consult local weather forecasts, meteorological models, or contact a meteorologist.