5/29/06: FCST: NY / NJ / MA / CT

[HAltschule]

The latest models continue their trend of a Southeastward moving MCS diving from Ontario into Eastern NY and NJ Monday morning into the evening. These events can lead to sever storms and isolated tornadoes in the Hudson Valley if all of the parameters line up. For Eastern NY (Albany south), the time of day is not perfect, but nevertheless their is plenty of instability and dynamics. 18z-21z soundings off the NAM suggest 1100-1500 J/KG of CAPE, LI's -3 to -5, no cap at all, high TT's and KI's and helicity values of 120-180. This all leads me to favor a good potential for strong to scattered severe thunderstorms around here tomorrow. I would expect that this kind of setup would warrant a slight risk since there are so many favorable parameters at this time. We'll see.

Disclaimer: These MCS's are difficult to predict here in the Northeast especially with the terrain and possible low level inversion issues. But it appears that the models are unanimous in developing scattered storms. So, we may be in for scattered supercells or broken lines of SVR storms with embedded supercells from about 11am in Eastern NY through evening (in NJ and NYC). The one negative to all this is that 0-6km wind shear is only 20-30kts...meager at best. Stay tuned.

 

[HAltschule]

The latest models continue their trend of a Southeastward moving MCS diving from Ontario into Eastern NY and NJ Monday morning into the evening. These events can lead to sever storms and isolated tornadoes in the Hudson Valley if all of the parameters line up. For Eastern NY (Albany south), the time of day is not perfect, but nevertheless their is plenty of instability and dynamics. 18z-21z soundings off the NAM suggest 1100-1500 J/KG of CAPE, LI's -3 to -5, no cap at all, high TT's and KI's and helicity values of 120-180. This all leads me to favor a good potential for strong to scattered severe thunderstorms around here tomorrow. I would expect that this kind of setup would warrant a slight risk since there are so many favorable parameters at this time. We'll see.

Disclaimer: These MCS's are difficult to predict here in the Northeast especially with the terrain and possible low level inversion issues. But it appears that the models are unanimous in developing scattered storms. So, we may be in for scattered supercells or broken lines of SVR storms with embedded supercells from about 11am in Eastern NY through evening (in NJ and NYC). The one negative to all this is that 0-6km wind shear is only 20-30kts...meager at best. Stay tuned.
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EDIT: 9:00 PM
Becoming more concerned that instability and dynamics will not be sufficient enough to get many big storms going. Weak convective MCS in the form of light to moderate showers is all that's forming right now upstream. Thus, I would not be surprised if this TRW potential busts and remains more showers/isolated non-severe thunderstorms instead. But I will keep my hopes up. :unsure:

 

[Saul Trabal]

A special weather statement has been issued at Weather Underground for the possibility of isolated severe thunderstorms this afternoon. Areas affected include the lower Hudson Valley and South Central New York State.