ZCZC SPCSWOMCD ALL ACUS11 KWNS 300210 SPC MCD 300210 MEZ000-MAZ000-NHZ000-RIZ000-CTZ000-300815- Mesoscale Discussion 1917 NWS Storm Prediction Center Norman OK 0810 PM CST Thu Dec 29 2016 Areas affected...New England Concerning...Heavy snow Valid 300210Z - 300815Z SUMMARY...Heavy snowfall, with rates in excess of 2 inches per hour, will continue across portions of New England throughout the night. Locally higher rates are possible, particularly across southern and central Maine. DISCUSSION...Recent snowfall reports and radar imagery confirm heavy snowfall, with rates in excess of 2 inches per hour (locally higher), is currently ongoing across portions of MA and NH. Recent report from Strafford county NH reported 5.6 inches in 2 hours. Additionally, recent dual-pol data from KBOX shows a signal consistent with ice crystal canting due to a strong electric field, increasing the confidence that isolated thundersnow may occur across portions of eastern MA and southern NH. Heavy snowfall will continue across this region for the next hour or so before shifting northward. Farther north (across southern ME), snowfall rates have gradually increased over the past few hours within an organizing snowband. Recent GYX radar imagery (around 0204Z) now shows a well-developed band of heavy snow from SFM to just south of AUG. Dual-pol data from GYX confirms good ice crystal growth within the dendritic layer and snow aggregation in the lower levels across this region as well. Strong mesoscale forcing for ascent provided by robust warm-air advection is expected to persist throughout the night as the surface low continues to deepen. Additionally, large-scale forcing for ascent will increase as left exit region of a strong upper level jet steak moves over the region. As such, the heavy snowfall is expected to continue overnight, gradually shifting northward/northwestward towards more of central ME. ..Mosier.. 12/30/2016 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CAR...GYX...BOX... LAT...LON 44307166 44987095 45766946 45716824 45226771 44716779 44346870 44086940 43857010 43237050 42747086 42277115 41877161 41917186 42247212 42677229 43267231 43587218 44307166 NNNN