Model guidance continues to support low pressure entering the Ohio Valley, with secondary low pressure developing south of Long Island and passing over SE MA while deepening. Precipitation should begin to fall in Keene by midnight Wednesday. The NAM is considerably slower than the rest of the guidence and will be discounted for now. With the elevated warm layer maximum below freezing still 12z Wednesday, should see only snow through at least 7am. Beyond that point, temperatures rise above freezing between 800 and 700mb, with 850-700mb thicknesses around 1560m. Boundary layer temperatures will still be well below freezing, with 1000-850mb thicknesses around 1285m. So we will see a period of snow mixing with and changing to sleet through noon, with freezing rain entering the mix after 10am. Freezing rain, mixing with sleet, will fall through Wednesday afternoon, before changing back to snow by 7pm as heights crash behind the storm. The GFS has kept light precipitation going through Thursday morning, and the ECMWF keeps the column fairly moist, so snow showers may continue past midnight Thursday through the morning commute.
General consensus is for a widespread .6" to 1.5" of water equivalent in SNE, with highest amounts along the south coast, and between .6" and .9" in Keene. Model QPF consensus is for .2" to .3" to fall by 12z Wednesday, with precipitation becoming heavy after 6am. Total snow accumulations of 3 to 5 inches can be expected before the changeover. During the greatest precipitation rates, ptype will be sleet, maybe some freezing rain. Another quarter inch of sleet will likely be mixed into the top layer of snow. Freezing rain will fall through Wedensday afternoon, with at least a quarter inch of ice accretion expected at this time. Light to moderate snow on the backside of the storm may accumulate another 1 to 2 inches through Thursday morning.
Current Forecast:
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