I probably should have done this earlier but I just got around to taking a look at the 18Z model data. — I’ve been so busy and so tired I did not get a chance to look at it earlier. There is no doubt that the 18Z short-range models such as the 3km NAM/Rgem /HRRR and they are all wetter than they were at 12z and at 6z.
Not only are they wetter but the precipitation pushes deeper into Virginia now reaching up to Washington DC and past Charlottesville and into Roanoke in Southwest Virginia.
18Z nam
This clearly does increase the threat of ice storm conditions being met in Southwestern and Central Virginia.
In addition in many areas which have snow on the ground which is currently covered with sleet and freezing rain glaze because of today’s occasional sleet and drizzle…. the freezing rain and sleet which develops on Saturday will crystallized more rapidly than it might normally with temperatures around 30 or 32 degrees.
Clearly with this short-range trend increase in the amount of moisture and pushing the deeper into interior Virginia and up into Northern Virginia the ice storm threat for Central and Northeast Virginia as well as the Southern Virginia Piedmont and the southern portions of the Shenandoah Valley appears to be increasing.
18z HRRR model valid 8AM FEB 13
18z HRRR model valid 11AM FEB 13
18z HRRR model valid 1PM FEB 13
The relative good news is that both the 18Z HRR and 3km NAM models do show temperatures going above 32 degrees in much of the Central and Southern Virginia Piedmont — Lynchburg Richmond Roanoke Charlottesville by 1–3pm in the afternoon. So if the precipitation is delayed at all that may reduce the icing to some degree
