NWS survey crews determine storm damage in Central Virginia


National Weather Service crews were dispatched to several locations around the region Monday morning to survey the damage done by yesterday's severe weather.

The NWS has the final say on whether or not the damage was tornadic in nature or was done by straight-line winds. If they determine the damage was done by a tornado, they will also determine the estimated wind speed and EF rating of the tornado.  

What the survey teams are looking for to make their determination as far as what created the damage is what direction the damage occurred in the path of the storm.  If all of the damage seems to be unidirectional, all blown down in the same direction, they are likely to determine it was created by straight-line winds.  However, if the damage on either side of the damage path is blown down in one direction on the left side and the opposite direction on the other side of the path, it's likely it was a tornado that caused the damage. There were several reports by emergency personnel along the way reporting they spotted a tornado so the NWS is fairly confident that that is what they will find through their surveying today.  

The way that they determine the strength of the tornado is with the Enhanced Fujita scale. Different wind speeds have a tendency to produce varying amounts of damage to distinct structures. Weaker tornadoes like EF0 or EF1 tend to do light to moderate damage like peeling up roofs, broken branches, overturning mobile homes, and windows and glass broken. An EF2 tornado would do considerable damage like roofs turn off well-constructed homes, mobile homes completely destroyed, large trees snapped or uprooted and cars lifted off the ground. An EF3 or EF4 tornado would do severe to devastating damage like entire stories of well-constructed houses destroyed, trees debarked, heavy cars lifted off the ground and thrown, whole well-constructed houses and whole frame houses completely destroyed and leveled. EF5 tornadoes are absolutely catastrophic to anything in their path. 

So survey crews will look at the path and scale of the damage to make a determination and will present their findings later in the day.  I spoke to them earlier today and they said due to the large scale of the damage and path of the storms it may take them until late in the day to have a full report. Chief meteorologist John Carroll will have updates for you as the information becomes available. 

Meteorologist Jason Caterina

Mobile County

Baldwin County

Northwest Florida