Winter Storm Warnings remain in effect for the entire region
•A look at the morning data shows the precipitation has begun to push into the lower Hudson Valley with rain being reported at White Plains.
•Precipitation will continue to spread from south to north between 5AM-9AM
•The track of the storm is a touch further west and both surface temps and upper air temps are also a touch warmer
•Warmer temps will cause most areas with the exception of the higher elevations to start out as a period of light rain
•Short range models show rain changing over to snow between 8am-10am with the valley locations taking the longest to switch over
•Snow begins to fall heavily almost immediately after going from the transition of rain to snow
•Roads will initially remain wet due to warm surface temps, but heavy snowfall rates will overcome the surface temps leading to deteriorating road conditions first on less traveled roads then to major highways
•Snowfall rates will approach 1-3 inches per hour by afternoon into the early evening hours, this combined with increasing winds will lead to times of low visibility by this afternoon
• Snow tapers off from west to east between 9PM and 1AM
•Heavy wet snow combined with gusty winds and partially leafed trees may cause isolated power outages
Latest Snowfall Guidance from high resolution short range models:
Morning models have picked up on the warmer temps and the slight western jog in the storm track which may cut back on some early accumulations across our southern most zones and parts of the mid and lower Hudson Valley. We are going to slightly adjust accumulations in some of these zones. Early season storms with very little available cold air can tend large variables in accumulations across small areas.
Our region is rich with microclimates which was the inspiration behind making this zone map. We are trying to factor a few things this morning, initial snow accumulations wasted to a brief period of rain, warm surface temps, and snow ratios starting out lower than 10-1. Basically all forecast models show snowfall accumulations based on a 10-1 ratio, meaning every inch of liquid precipitation is equivalent to 10 inches of snow, that ratio depends on air temps, and with some areas starting out above freezing we may see ratio’s start at 8-1 (heavy wet).
Updated Snowfall Forecast:
Zone 1: 4″-8″ ( Less NW & More SE)
Zone 2: 8″-14″ (Most in higher elevations)
Zone 3: 6″-12″ (Isolated pockets of higher amounts possible)
Zone 4: 8″-14″ (Most across the highest terrain)
Zone 5: 8″-12″ (Pockets of over a foot possible)
Zone 6: 8″-12″ (Most across higher terrain)
Zone 7: 6″-12″ (Most across hill towns)
Zone 8- 5″-10″ (Less south and lowest elevations)
Zone 9- 3″-8″ (Battle zone,More North, Less South
Below is the HRRR short range model showing the change over from rain to snow between 8-10AM across most of the region:
You can see how quickly rains turns into a heavy snow this morning with the simulated radar image from the HRRR model, so don’t be fooled by the onset of rain, things will go downhill quickly.