Archive for July 3, 2011

AFTERNOON UPDATE…

I just wanted to post an update this afternoon as temperatures have risen into the mid-nineties across Hampton Roads. Abundant sunshine combined with a westerly wind have caused the heat to really crank this afternoon. So far, convection has been absent for the most part. Forecasters are still saying that will change as we head into the late afternoon hours due to a thermal trough moving through later on from central VA. To make thunderstorms develop, you need the upper atmosphere to cool down which creates instability. (Warm air is lighter than cold air so the warm air near the surface rises more rapidly when the air aloft cools). Other ingredients are necessary to create thunderstorms, but today, we’re lacking the cooler air aloft. There’s plenty of humidity available for thunderstorm development. We’ll see if that changes as we head through the evening. Tomorrow, forecasters are saying that we could see more thunderstorm development as the front will be closer to the region. However, as noted in the NWS update this afternoon, the next few days will be a real forecast challenge when it comes to the timing of the expected thunderstorms. Hey, that’s typical of summer in Hampton Roads.┬áTake care and stay cool!

Leave a Comment

A WEAK FRONTAL BOUNDARY WILL BE A CHALLENGE FOR FORECASTERS SUNDAY THRUOUGH TUESDAY… SHOWERS AND THUNDERSTORMS ARE POSSIBLE EACH DAY, BUT THE TIMING AND COVERAGE WILL BE THE ISSUE THIS HOLIDAY WEEKEND

A slow moving weak cold front will create a real forecast challenge for meteorologists in the Mid-Atlantic States through Tuesday. Showers and storms are expected to pop up mostly during the afternoon and evening hours. The coverage, timing, intensity and placement of these storms are impossible to nail down so if you are going to be outdoors, just be prepared for thunderstorms that could produce heavy rain and frequent lightning. Severe weather, although possible, isn’t likely. The front should wash out by Wednesday but another front may move into the region later in the week. We’re at the time of year when cold fronts have difficulty moving through our region. They frequently stall in our region and slowly wash out. However, with heat and humidity levels on the high side, it doesn’t take much of a trigger to set off thunderstorms. One issue will be whether the storms fire up when firework displays are taking place. At this time, the National Weather Service indicates that there is a 30 to 40% chance of storms over the next few days. I’ll have an update on Monday morning. Thanks for reading and have a great day.

Leave a Comment