Analysis: Severe weather possible Tuesday

An unusually organized area of low pressure, and an associated mid level disturbance, is expected to track through the Northeast states on Tuesday into early Wednesday morning. Riding on the periphery of a large mid and upper level ridge, this disturbance will gain extra energy along a thermal and height gradient which exists from the Great Lakes into the Northeast states. The low pressure center, at the surface, is expected to track from the Great Lakes into Central and Northern New England.

The track of the low pressure center will, at the surface, push a warm front northward through the Mid Atlantic states from late Monday Night into Tuesday morning. This warm front is likely to push through New Jersey to a position near Northeast New Jersey, New York City, and Long Island by daybreak on Tuesday.

Along this warm front, forecast models suggest an early morning strong and severe thunderstorm threat may materialize. While these threats are always a bit more conditional and dependent upon the juxtaposition of several key ingredients, this setup seems conducive to activity. The presence of very high dew points, and the nose of a favorable low level jet, are likely to overlap with increasing instability.

This could produce strong thunderstorms with torrential rain and lightning. In addition, along the warm front, locally favorable low level shear could enhance rotation in these storms. This would suggest the potential for a weak tornado or two near this front from the morning into the early afternoon as it shifts past the NYC Metro and into Western New England. The tornado threat is likely to be localized near the warm front — so tracking exactly where that is located as instability increases during the morning hours will be critical.

As mentioned, this warm front begins its trek slowly northeastward throughout the day. This may allow a severe storm threat to continue over Long Island , Southeast New York, and Connecticut as the day continues. This threat may actually increase — and be maximized — as the front tracks into East-Central New York and Western New England. Here, daytime instability will be maximized and juxtaposed with enhanced shear along a warm front. Additionally, a strengthening low level jet during the afternoon may further enhance the potential.

During the afternoon over New Jersey and Southeast New York, mid level height rises may actually act to inhibit thunderstorm development. With a prefrontal trough back to the west over Pennsylvania, additional activity is eventually expected to develop and move eastward toward the area near or after sunset. The strength and organization of this activity is a large uncertainty at this time, and will depend greatly on the timing of the system as well as warm sector development.

If this activity can become more organized, it likely will track into our area between 8-10 pm, with another enhance threat for strong and severe thunderstorms –mainly with the potential for wind damage and an isolated tornado. But more sporadic activity to our west during the afternoon would likely considerably weaken by the time it gets here. This, again, will have to be monitored very closely during the day.

To summarize, the threat for strong and severe thunderstorms on Tuesday is certainly higher than normal. However, it remains highly conditional and greatly dependent on several near-term/mesoscale factors which won’t be ironed out until the morning hours on Tuesday. The greatest potential for severe storms currently appears to exist along the warm front as mentioned above, from Northeast NJ/NYC/Long Island during the morning and then into New England during the afternoon.

Stay tuned for further updates including video discussions and a live blog which is currently scheduled to go live at 12:00am Tuesday morning.