Welcome in to our discussion about the severe weather potential heading into our last weekend of July. We’re going to break it down to the locations that are at greatest risk of severe weather, the greatest weather risks within, and the timing of all of these. Let’s begin:
We show this map quite often here at WeatherNation. It’s the Storm Prediction Center’s severe weather outlook. The categories are broken down from General Thunderstorms which is shown in light green, to High which is shown in pink. In the picture above, the darker green means marginal risk and yellow means slight risk. In short, these colors mean that isolated (a few to several) severe thunderstorms are possible with hail up to 2 inches in diameter, a tornado or two will be possible, and wind gusts of 60 miles per hour or stronger will be possible. Once we get into the orange and red colors, that means tornadoes or damaging winds are much more likely and/or hail up to a few inches or larger will be possible. Fortunately it doesn’t appear that will be the case through the weekend.
The eastern United States is going to be the focus for most of the severe weather the next couple of days. A strong low pressure system will evolve out of the Great Lakes and Mid-Atlantic Friday into Saturday, spreading heavy showers and thunderstorms from Pennsylvania and New Jersey, southward to the Carolinas and parts of the Gulf Coast states.
Flash flooding will be the biggest threat moving forward, possible from Kentucky to West Virginia and further east to the Chesapeake Bay area. There, up to several inches of rain may fall Friday through Saturday. The timing will be from mid-morning Friday through mid-morning Saturday, roughly a 24-hour period. Areas that you see in orange and red, in the image above, will stand to get the most rainfall according to our forecast.
The severe weather threat lingers for the first part of the weekend across the Southeast. A weak cold front will be draped across this area, helping to bubble up showers and thunderstorms. Some may become severe with hail, damaging wind, an isolated tornado, and flash flooding being the biggest threats. These storms will be most likely between 1 p.m. and 10 p.m. Saturday.
The western United States will not see as much severe weather, however monsoon-related thunderstorms will be likely across the Four Corners. From Arizona to California, New Mexico to Utah, and Colorado to Wyoming the thunderstorms could pack some heavy rainfall. Flash flooding will be the biggest threat across the Southwest due to the slow movement of storms and higher moisture this time of the year.
Highest amounts of rain Friday and Saturday will be likely in New Mexico and Colorado in particular. Hike early in the day to avoid thunderstorms in the afternoon. Adhere to weather warnings that may be issued for your area.
For WeatherNation, Meteorologist Steve Glazier