Tuesday, January 13, 2009

Initial Arctic Front Arrives Wednesday Morning

The first of several waves of arctic air will move through central Virginia during the pre-dawn hours Wednesday. Dew point temperatures (a measure of moisture in the air) will drop from the upper 20s to the single digits as the extremely dry air mass settles into the state. Despite seeing some sunshine Wednesday, high temperatures in central Virginia will only reach the upper 30s. A stronger surge of arctic air is still expected to arrive Thursday with brisk northerly winds expected in the area. I am still expecting a period of nearly two full days in which the temperature never reaches the freezing point (melting point). The latest data continues to show a very dry air mass with a lack of focus for snow over the next 7 days. Our best chance is a slight one on Sunday. Have a great Wednesday!

Zach

Update on Two Tuesday Lows

Two low pressure systems are moving through the East Tuesday. The northern low is tracking through the Midwest into the Northeast, bringing strong winds and blowing snow to that region. The cold front associated with this storm will pass through Virginia Tuesday evening, bringing the first shot of colder air this week.

The southern low is moving through the coastal regions of the Deep South Tuesday morning, and will track northeast into the Atlantic Tuesday afternoon. Southeast Virginia will have a chance for rain from this coastal storm, which may mix with a few snowflakes this afternoon in Central Virginia. Precipitation chances, though, are very low the farther northwest you move away from the coast.

As Zach mentioned in his blog update Monday evening, there will be another shot of colder, Arctic air plunging into the region later this week. Another fast-moving low pressure system will usher in a second hit of that cold air to the Midwest Wednesday, reaching Central Virginia Thursday. This will likely be a dry system in Central Virginia, with only a slight chance for a few snowflakes. What we do expect, though, is much colder air. Lows will fall into the teens Friday and Saturday mornings.

--Carrie