Category Archives: Weather Updates

Update

Latest NAM model data just became available.  (Available an hour later due to daylight savings time. )

Thermal profile for PHL still supporting snow, but marginally.  Latest QPF has increased to 0.75 inches water equivalent.  Starts about 8am,  ends about 6 pm

Winter Weather Update

Both the NAM and GFS have low pressure moving along a frontal boundary to our south and intensifying somewhat as it moves over the coast Friday.

Thermal profiles in both models support snow, however temperatures at the surface will be close to 32.  With QPF values of about 0.45 inches water, this would be a significant storm IF it were winter.

However, it’s March, the sun angle is high and insolation through the clouds challenges accumulation on roadways.  The snow will be occuring,  not a night, but during the morning and afternoon.   So  accumulation on grassy surfaces and sidewalks is possible,  but accumulations on roadways will be limited and short-lived.

Too many factors to really be able to predict accumulations accurately.  Best guess is an inch or two on grassy surfaces,  and a slushy coating on roadways.   The precipitation may be heavy during the afternoon, so visibilities while driving may be poor.

This time of the year, weather forecasting has its lowest accuracy, so changes are likely.