What Blew Through?June 26th, 2012 at 9:54 am by Jeremy Wheeler under Weather
The quick answer to “What blew through?” is simple. It was a potent cold front. So why don’t all cold fronts produce weather like yesterday’s storms? That’s a lot more complicated to answer. Before the storms arrived we had plenty of heating and humidity. Highs were in the 90s and dewpoints (moisture) were in the 70s. This makes the atmosphere very unstable. Kind of like when you have a room full of cats, and a huge fluffy mouse walks into the room. There is a high potential for the cats to get up and chase the mouse. In yesterday’s case, there was a high potential for air to rise and create storms. However, yesterday we also had some strong upper level winds which were brought down to the surface through mixing. In the end we had about 37 reports of severe weather with many more reports below severe criteria:
A severe wind gust is one with speeds of 58mph or greater. Severe hail used to be 3/4″. Now it is 1″. that is a recent change by the National Weather Service over the last couple of years. The strongest wind gust that I saw was 67 mph 2 miles SSE of Sandbridge, VA. Langley had a gust to 54mph, but that was just below severe limits. There was a gusts to 56mph in Poquoson, and a gust to 47mph in Elizabeth City. There were large trees knocked down in York county around Heritage Hamlet. There were also trees down in Currituck, NC. A large tree fell on a house at Loxley Place in Portsmouth. I didn’t have a photo of that tree, but here are some others. Loren Scott in Hampton had a neighbor’s tree fall on her porch. Luckily there was no damage to the porch:
Here is another photo of a broken tree from Alexis Arrington. She didn’t give a location:
Here is one more from Portsmouth. It was sent in by Christy Wynne:
We also had several reports of hail. There was 3/4″ hail near Whaleyville. There was nickel sized hail in Sunbury and Elizabeth City with numerous reports of small hail around the region. Doris (my Eastern Shore weather watcher) said that there was quarter-sized hail in Birds Nest, VA. Don in Toano also had quarter-sized hail. Overall the area picked up a half up to an inch of rain.
Most of that rain fell within a half an hour to an hour, but some locations had rain a little longer. Today, a large area of high pressure will build in and provide us with sunshine. We will have some breezy north winds which will keep us cool and dry. Today highs will be in the upper 70s with dewpoints down in the low 50s. Winds will gust up to 25mph. We’ll stay dry tomorrow, but we’ll warm up a bit to the mid 80s. The strong heat will really build back by Friday. Highs will be in the mid-upper 90s going into the weekend. there may even be a couple of 100s inland. We may not get much of a cool down early next week. Some of that though depends on Debby.
Tropical Storm Debby is still in the Gulf of Mexico. It has been producing very heavy rain across most of Florida and southern Georgia. It was moving slowly east at 3mph with maximum sustained winds of 45mph. It’s interesting that the cold front that moved through our region quickly pushed south, and was actually located a couple hundred miles north of Debby. Some of the dry air in the upper levels pushed farther south though. So I think some of that is wrapping into the storm. Of course there was already some dry air there to begin with.
Also, since it has sat over the same area for a while; Debby is upwelling some cooler water underneath it. Debby is on a eastward track now which will run it into Florida in the next day or two. This should all work to weaken the storm considerably. It is forecast to be a depression as it moves over land. However, the official forecast is for the system to depart the eastern shore of Florida and head back over water. If it does this, then it can re-intensify over the Gulf Stream. The official track also bends Debby north a little bit towards the end of the track. The GFS and European models, however, keep it farther south.
There is still disagreement in the models as Debby is still under a weak steering current. But a big trough in the upper levels is pushing south along with the cold front. This should help to shove Debby eastward and at a quicker pace. Here are some of the models, regardless:
For now my money is to the east, but I do think it’s possible that Debby could get eaten up. There are a lot of things working against it. One other thing that I didn’t mention is wind shear. It has been working on the storm for a couple of days. So we’ll have to see if Debby can even survive in the next 24 hours. Till then enjoy the nice weather today.
Meteorologist: Jeremy Wheeler