Breaking down New England's thunderstorm chances Tuesday & Wednesday

This week will be unsettled at times for New England, with thunderstorms and showers possible somewhere in the region pretty much everyday for the rest of the week. For this afternoon, enough energy from the departing trough will be present to spark scattered thunderstorms across northern New England. Southern New England will see much more isolated activity today. The greatest chance for storms will be 1pm-8pm.

GFS showing potential weather around mid to late afternoon today:

Photo byGFS/Tropical Tidbits

The highest storm chances for northern New England will be anywhere away from the coast line. The coastal plain of northern New England will be in the same boat as southern New England with only spot/isolated chances. The biggest question with storm coverage will be how much instability can develop after this morning's rain and clouds as well as how much sun can break through the clouds to energize the atmosphere this afternoon.

There will be a chance for some storms to become strong to severe, but widespread severe weather is not expected. This threat looks more isolated with more storms staying below the threshold for severe. For storms that do go severe, damaging winds, hail and torrential rain will be the greatest threats. After the overnight flooding rains in portions of Vermont, where downpours set up today will need to be watched closely.

Photo byNew England Storm Center

As far as today's ingredients for severe thunderstorms, moisture and lift will be sufficient to get storms going and shear looks sufficient to allow storms to sustain themselves to be able to strengthen. As usual, instability is the big question mark. CAPE values will build to the 800-1,400 range for much of northern New England, which doesn't jump off the page for severe weather.

On Wednesday, an area of low pressure will exit the Great Lakes and pass just to the north of New England, dragging its fronts across New England. This will lead to an unsettled day with scattered showers and storms possible for most of the day. Activity will likely peak sometime in the afternoon and it won't be an all day washout for anyone.

Photo byNew England Storm Center

Scattered storms will begin to fire along the system's warm front as it passes through the region. Storms will then continue to fire in the system's warm sector until the cold front clears the area Wednesday night.

The severe threat is low for Wednesday on account of meager instability with cloud cover likely dominating much of the day. Shear and instability also look rather weak. If clouds break quickly for the afternoon, however, enough instability could build for isolated strong to severe storms, but, again, this threat remains very low at this point.

HRRR showing scattered showers and storms all around Wednesday afternoon:

Photo byHRRR/Tropical Tidbits

The greatest threat with Wednesday's storms will be the potential for localized flash flooding. Storms will be able to produce torrential downpours at times. This threat initially wasn't looking like a big issue, but after the flooding rains in portions of Vermont and New Hampshire overnight, the ground has become primed for additional flooding issues.

If the areas that have seen several inches of rain over the past 12 hours see multiple storms on Wednesday (which will be possible as storms will be firing and moving through all day), it could spark additional issues. The Weather Prediction Center has upgraded much of Vermont and New Hampshire into the "slight" category (level 2 of 4) for excessive rainfall on Wednesday.

Photo byNew England Storm Center