Category Archives: Winter Weather

Winter Weather

NO SNOW, LIGHT FREEZING RAIN AND SLEET

The latest NAM data is becoming available.  Precipitation, very light, expected to begin about 7 am Wednesday.  As I’ve been saying since last night, temperatures in the upper atmosphere will be too warm to support snow in Philadelphia and the immediate adjacent PA counties and south Jersey.

In the lower levels of the atmosphere and at the surface,  temperatures remain below freezing until 9-10am in and around PHL,  so precipitation will fall as a brief period of light sleet and then light freezing rain, changing to all rain by late morning.

The issue for tomorrow morning will be icy conditions on untreated surfaces, not accumulations.  Even a thin coating can be slippery.

One more thing…QPF values are very low in the morning, less than 0.09 inches water.  The heavy rain will be during the afternoon.

 

Winter Weather

Tuesday Wet Snow Forecast

Still away on vacation 🌴, but I thought I’d chime in on the weather for Tuesday.

An upper air disturbance will move across the area on Tuesday.  The latest NAM model has moved up the QPF to about 0.20 inches water. Upper air temperature profiles marginally support the precipitation falling as snow, BUT near surface air temperatures will likely be above freezing for much of the time.  Additionally, ground temperatures have been above freezing for awhile.

As a result, a very wet snow is expected with very little accumulation — likely just a coating, more on grassy surfaces.