Messy Morning commute: Ice to Cold Rain.

SO it has been snowing for a while!??? I am getting reports of 2-3″ around our area, and we should get another C-2″ by the end of the night before it starts changing over to sleet/freezing rain and then eventually all rain.

We can see the warm front lifting into the area, see the contrast of temps running through S LI into Jersey and Mid Atlantic. This will continue to lift and as it lifts N the snow will change over to sleet/rain/ice then all rain as temps continue to rise throughout the night.

hrrr_t2m_neng_1

Now here is the thing to watch…Yes we will become plain rain by late tonight…BUT, the key to our troubles is the fact that ground temps (sfc temps) take MUCH longer to react to warming/cooling than the air temperature. SO, while tomorrow morning we will be close to or at/above 40°, the surface temps will look like this:

hrrr_tmpsfc_nyc_15

So, see that, for our area temps around freezing to just above and even more so getting further N into the valleys. Along with a fresh coating of 1-3″ of snow/slop/freezing rain (which will wash away eventually) my concern is that rain will be freezing on contact with the surface in spots. This can be very dangerous for travel. This threat should end midday the latest as we transition to rain, heavy at times as a strong LLJ of 50-75kts and high 700mb Vertical Vorticity along with heavy rain brings the dynamics deeper down the column w/ steep lapse rates.

nam_2016021518_021_41.03--73.86

I would NOT be overly surprised if some see Thunderstorms w/ these good dynamics.

Forecaster: Remy M. 

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