The three H’s enter the picture plus a look back at June 13th storms
For the first part of this summer of 2013 clouds and above average rainfall have been the main weather story for Fredericksburg and most of Virginia. Now it’s time for the three H’s (heat, haze, and humidity) to dominate weather news, with the NWS Sterling morning forecast discussion tossing out phrases like today being “the beginning of the warmest week of year so far” and terms like “sultry” to describe how the nights this week will feel. In other words it’s time for more typical July weather to assert itself over the ‘Burg. More on that in tomorrow’s post.
Meanwhile the NWS Sterling office completed its storm survey of the events of June 13 and has concluded that tornadoes indeed occurred that afternoon. There were several reports of funnels around the Fredericksburg area that day as well. Here is the survey map the Sterling office posted:
As you can see there was an EF-0 tornado recorded near Thornburg that had maximum winds estimated at 80 mph that damaged several buildings and trees and a couple of billboards on I-95 before overturning two recreational vehicles at a dealership east of the interstate. Another EF-0 tornado then occurred in southern King George county with maximum estimated winds of 70 mph which created another swath of tree damage, and a third EF-0 tornado dropped over southern Maryland with maximum winds estimated at 75 mph.
The time frames and damage paths shown on the map are characteristic of a single cyclic supercell thunderstorm that created all three tornadoes as it traveled across the region. Such a storm goes through several cycles of intensifying and weakening, with the potential for creating multiple tornadoes along its path during the multiple intensification stages. As I recall that day the shear conditions (change of wind speed and direction with height) were much better over eastern Virginia closer to the Bay and the Atlantic. What likely happened was that this storm formed southwest of the area before entering the higher shear zone and ramping up to become a supercell. The entire writeup can be found on the NWS Sterling website.
No such storms are expected over the next few days…just the three H’s!