Another Chance For Elevated Convection For Monday. Also, Snow...

As yet another low pressure system pushes into the Northeast, NY is faced with the possibility of thunderstorms associated with elevated convection. The thunderstorms are expected to pop up along an occluded front Monday morning, and push northeast from western NY to eastern NY throughout the mid-morning and afternoon hours.

The GFS is being a lot more generous than the NAM with elevated CAPE in NY, with values of over 800 J/kg over Albany at around 2pm EDT. NAM is suggesting more moist mid- and upper-levels, with elevated CAPE values of less than 100 J/kg. P-Wat values of about one inch will help fuel the storms as they push through NY.

The main discrepancy between the models is the overall strength of the mid- and upper-level jets over NY. The GFS is forecasting stronger mid- and upper-level winds, which would advect steeper lapse rates into these levels and provide the larger elevated CAPE values. I tend to go with a mean value over Albany, since the GFS tends to overestimate CAPE values, and the NAM slightly underestimates it. Realistically, I would expect Albany to hit elevated CAPE values of 200-300 J/kg...enough to trigger some boomers!

This line of possible thunderstorms will also bring heavy rain, with a large portion of NY progged to receive over half an inch of precipitation. Lesser values are forecasted for areas not fully affected by this line of storms.

Following the passage of the occluded front, snow is expected throughout most of NY. Temps will reach below freezing at times in much of the western half of NY, which could see some snow accumulations. Areas affected by lake effect could see very generous snowfall totals for this time of the year, with 3-6"+ expected in the stronger lake-effect bands. In the eastern half of NY, temps will be a bit warmer, so valley areas could see some snow showers mixed with rain, but little to no accumulation. Elevations above 1200' in eastern NY can expect to see some snow accumulation from the trailing end of this storm.