Thunderstorm threat Tuesday

A cold front will approach the region tomorrow with overspreading clouds and a chance of showers. Colder air aloft coming in behind Hanna will allow some conditional instability to develop (around 500 to 800 J/kg) despite a lack of solar heating. In addition, a mid level jet of 40 to 60kts will create a significant threat for damaging winds. The possibility exists for a squall line formation to sweep through tomorrow afternoon around 3 in Keene, reaching eastern New England by 6. PWATs around 1.5" will allow some heavy downpours to occur, and any areas that received flooding from Hanna may have to deal with some renewed problems. SPC day 2 outlooks puts the region in a 30% risk for severe weather which supports my confidence in an active weather day tomorrow.