Tuesday, January 18, 2011

Will it Snow on Friday? - NO BUT...

It appears that the Global AAM pattern is the key to accepting the forecast solution which takes the low pressure out to sea before any moisture can interact with cold air over Central VA and NC.  Next week I believe we will not be so fortunate as the weather pattern will be very supportive of a mixed precipitation event that could be very serious.

Cold High Pressure is expected to position itself over New England.  Arctic air in this situation builds a wedge east of the Appalachians while moisture from a Low approaching west of those mountains overruns the cold air.  At the surface snow quickly changes to sleet and freezing rain.  A secondary low tends to form near the east coast and take over as a primary storm as it moves northward.

Therefore a scenario that is believable and common in NC and VA classic ice storms appears to be very likely between the 26-28th.

Miller-B storm approaches west of the Appalachians setting off a classic Cold Air Damming
Scenario.  Diagram by Dean Grubbs.

1 comment:

  1. The New England high will be in retreat mode. This rarely leads to anything significant in Raleigh and Richmond. We see some snow or sleet and helplessly watch as it changes to a 33-34 degree RAIN.