Snookered

I am beginning to wonder who it is that is advising the St. Mary's County Public Schools regarding its decision-making to close the schools due to predicted weather.  Today is a perfect example of a poor decision to close the schools.

 

Meteorology 101:  Snow occurs when warm, moist air aloft flows over a sufficiently deep layer of 34 deg. F or colder air at the surface.

 

Yesterday, the National Weather Service, the Weather Channel and the news media were all warning of heavy snow today, including St. Mary's County.  Our local amateur weather-guesser Floyd Abell was predicting 5 inches of snow.  However, it simply did not make any sense.  Yesterday's high temperature was 36 deg. F aboard the naval station and closer to 40 deg. F inland, as evidenced by all of the previous snowfall that melted.  A pre-existing surface-based layer of sufficiently cold air was not present.  Therefore, a source of cold air advection into the local area would be required for a heavy snowfall to occur.  For cold air advection to occur there must be a strong high pressure center located between the Great Lakes and Maine with cold, north to northeast surface winds extending into the local area.  Notably, the requisite high pressure center to the north was not present on yesterday's surface analysis charts or the prognostic charts.  How could something so fundamental be overlooked?

 

 

At midnight last night the 7:00 PM (00Z) radiosonde sounding (atmospheric profile) from Wallops Island was available.

 

 

In comparison to the 7:00 AM (12Z) sounding, it showed that the air mass had significantly warmed.  An analysis of specific forecasting indices showed a definite change from snow to a mixture of rain, snow and sleet.

So, as early as midnight last night there was very clear, conclusive  evidence available that the forecast for a heavy snowfall today was extremely questionable.  So, why did they close the schools?