Good morning, I hope everyone is going to have a great Sunday! After a wet past few days, it’ll be nice to see less rain in the forecast. KHBG, the weather station in Hattiesburg, recorded 1.9” of rain over the past few days, with a strong storm yesterday dropping 1.1” in just an hour!
Those intense rainfall rates occur because storms are moving very slow, and because they have a lot of moisture to work with.
Looking at the current PWAT values, we can see that we remain in a very moisture-filled atmosphere, not that you needed me to tell you that.
This part won’t be changing, so if there is a storm overhead, it may drop a lot of rain in a short period of time.
The good news, though, is that though the heavy rain chances are still going to be hanging around, they’ll be lower than the past few days, where we had frequent storms most days.
Today, we have a much lower chance of thunderstorms, as yesterday afternoon’s run of the HRRR model showed.
Generally, modeling is indicating that the best chances of thunderstorms will be right along the Gulf Coast, with another area along and North of I-59. Areas like Waynesboro are more likely to stay dry, but of course, summer thunderstorms are very hard to pin down.
Looking at some upper level charts, we’ll start with a current look at the atmosphere.
This is the 500 mb map for this morning, annotated with High and Low pressure centers, as well as troughs and ridges. Troughs are areas of low pressure, and are marked with a red dashed line. Ridges are areas of high pressure, and are marked with a blue squiggly line. The black arrows show the flow of the wind around the main patterns.
This morning, the main feature across the United States is a large high pressure center centered across the Desert Southwest. There is a ridge extending from the center of the high to around Texarkana, which is continuing hot weather for Texas and Oklahoma, who are looking at a major and rare heatwave. Oklahoma City has a forecast high of 105F today and 108F on Tuesday!
Luckily, with us being on the edge of the ridge, we won’t see heat quite as bad. The Northerly flow over our area will help to moderate temperatures, but it won’t be cool by any means.
Since the ridge is exerting it’s influence over our area, you can see the troughs moving to the North, around us. Troughs are responsible for unsettled weather, and more intense thunderstorms. The higher pressure is preventing the troughs from digging South, so they’ll track over places like Omaha, Saint Louis, and Cincinnati.
This map is the same thing, but for Tuesday morning. The high pressure and ridge is more or less in the same place, and there is a new low pressure centered over Northeastern Alabama.
Usually that would indicate cooler or drier air into this area, but the winds at the surface are still strongly out of the South, pulling air directly from the very hot Gulf of Mexico, so we won’t see a really strong change in our weather.
This next map is the forecast for this upcoming Friday. A major change is coming, and that is for the ridge to basically dominate the entire southern half of the United States. Rather than having extreme heat in Texas or Oklahoma, we’ll probably see high heat everywhere south of Omaha.
As for our region, this is going to reinforce heat and humidity going into the long-range forecast, and this is an indication that we probably won’t be seeing much relief going into the last half of July.
In fact, the CPC’s 8-14 day forecast, which is valid for the last week of July, shows high probabilities of above average temperatures for most of the entire US, including our area. Most of the extreme heat will be further North, where the ridging is strongest, and the high pressures are centered, but we will certainly stay hot here.
The ridging, as I mentioned earlier, will significantly cut down our rain chances going into this week, and the 7-day rainfall forecast is reflective of this.
The folks over at the WPC aren’t seeing much for this area, with barely a few tenths of an inch over the next week. It stinks to see more dry weather coming in this late in the growing season, but hopefully there won’t be too many impacts with this drier and hotter spell. We are currently drought free, and I hope to keep it that way.
Most of the rain is forecast to fall Friday, as another weak frontal disturbance stalls out in the Tennessee Valley.
Day-to-day Forecast
Today
Partly cloudy, with a 30-percent chance of afternoon thunderstorms, with the best chances North of I-59. Highs in the low-90s.
Tomorrow
Partly cloudy, with a 40-percent chance of afternoon thunderstorms, with the best chances North of I-20. Some of the storms may produce strong wind gusts. Highs in the low-90s.
Tuesday
Mostly sunny, with a 30-percent chance of afternoon thunderstorms. Highs in the mid-90s. The heat index may reach 105F.
Wednesday
Partly cloudy, with a 20-percent chance of an isolated afternoon thunderstorm. Highs in the mid-to-upper-90s. The heat index may reach 107F.
Thursday
Partly cloudy, with a 30-percent chance of afternoon thunderstorms. Highs in the mid-to-upper-90s. The heat index may reach 108F.
Friday
Partly cloudy, with a 40-percent chance of afternoon thunderstorms. Highs in the mid-90s. The heat index may reach 108F.
Saturday
Partly cloudy, with a 20-percent chance of afternoon thunderstorms. Highs in the upper-90s. The heat index may reach 110F.
