Good morning, all! In my previous post for SW Mississippi’s forecast this morning, I laid out a lot of the big picture details for the Southeastern US, but we’ll be going over the same things here.
I’ll re-use a few graphics for simplicity sake, as we discuss the overall pattern that’s going to evolve over the next couple of days.
The main story is the intense heat! Excessive Heat Warnings are in effect for a good portion of the Southeast, including areas like Dallas-Fort Worth, Waco, Texarkana, Shreveport, Jackson, and Memphis. Lots of intense heat is going to be focused on the South for the next few days.
The actual Excessive Heat Warning is in effect through this evening, but dangerous heat will continue across portions of the country through the next few days, especially in Texas/Oklahoma.
The reason behind this is a major upper level ridge set up across the forecast area.
Looking at the 500 mb analysis for today, we see the main feature for us is the high pressure. The blue line indicates an extension of the ridge, and areas with high negative vorticity, and sinking air. This gives us an idea of where the highest heat may be found on any given day.
Today, since the extension of the ridge is centered over East TX and LA, that is where the worst of the heat is going to be confined at. NWS forecasts show high temperatures between 100-107F for much of East Texas and Northwest Louisiana, and 90s for the rest of the Southeast. That being said, the humidity will be much worse across the “Dixie” region, so the heat indices are set to be much higher across portions of the Deep South.
This afternoon, some places may hit 115F on the heat index readings, especially areas in North Mississippi or Eastern Arkansas. The areas under an Excessive Heat Warning are most likely to get to the 110F-115F mark.
Areas directly under the ridge are more likely to stay dry, while other areas will likely see frequent afternoon storms, especially across a frontal boundary draped across the South.
This front is going to spark thunderstorms across most of the Southeast. This map shows thunderstorms over Eastern TX, but they will be few and far between.
Heavier rain is likely over the Carolinas and the East Coast, thankfully not due to anything tropical-related.
Tomorrow
High pressure systems rotate clockwise, and that extension of the ridge is going to rotate along with the prevailing pattern, like a clock.
As you can see in tomorrows upper level map, the high pressure ridge will rotate further South, and stall over the Gulf Coast. This is going to allow Northerly winds to prevail across the Southeast, though there isn’t much dry air that would make us feel much better.
The main ridge also slides West, meaning that the extreme heat will also move a little further West. North Louisiana will see some cooler temps, as Shreveport drops from 103 today to 98 tomorrow.
The Carolinas and Georgia will continue to see more widespread rain and storms, keeping temperatures down from the rest of the South. At 83F, Columbia, SC is set to be one of the coolest places in the whole Southern US tomorrow.
With that, comes a risk of flooding. The WPC has this area under a marginal or slight risk of flash flooding today and tomorrow, as heavy rains continue throughout the next few days.
On the other end of the spectrum, Texas will remain dry as the ridge doesn’t let any storms form, and unfortunately, drought is going to continue and worsen for a lot of people out in Texas.
Monday
The upper level map looks a little different for Monday- there are two distinct high pressure centers with a ridge extending off into the Ohio River Valley.
Underneath the upper level ridge, a stalled out cold front will stay in place over the Gulf Coast, bringing lots of showers and thunderstorms across most of the Northern and Eastern Gulf. Texas will still be under the influence of the ridge, with negative vorticity and sinking air dominating the weather.
A small trough out in the Gulf of Mexico will cause more frequent thunderstorm activity in Florida, another area set to receive a lot of rain.
In fact, looking at the overall American Ensembles, we can see that above average precipitation is going to be a major factor for a lot of this upcoming week.
The hotspot along the Louisiana Coast is a feature that Jake mentioned yesterday, as potential flooding concerns look to increase for Coastal LA and MS. We do have more specific forecasts for that area, or you can consult your local NWS in Mobile or New Orleans.
The flood threat looks to increase for a lot of the Central Gulf Coast, so please do stay informed. Even thought his activity isn’t a tropical system, it can have big impacts. I should take this time to mention that we don’t have any tropical threats at this time, the NHC is not monitoring anything in the Atlantic at this time. That’s some really good news.
And, of course, the other major thing we’ve been talking about is more dry weather for TX/OK. More heat and dry weather is just set to keep going, and we probably won’t see many changes to that.
If you follow my Twitter, you may have seen this, but I wanted to draw attention to a post by Noah Bergren, a meteorologist in Paducah, KY.
He has been keeping tabs on this, and the GFS has been showing, for a couple runs in a row now, a monster ridge over a lot of the Central US. Since hot air expands, when there is a lot of hot air, that means that the height it takes to reach a certain point in the atmosphere is taller. This ridge currently being depicted is a lot stronger, and would indicate a lot hotter air is still to come later on in July.
Don’t worry about specifics, and we will certainly keep you updated, but signals are pointing to mid July being a scorcher.
3-Day Southeast City Forecast
| Dallas, TX | ||
| Saturday | Sunday | Monday |
| High: 106F | High: 102F | High: 104F |
| Low: 82 | Low: 82 | Low: 80 |
| Precip: 20% | Precip: None | Precip: None |
| Houston, TX | ||
| Saturday | Sunday | Monday |
| High: 99F | High: 100F | High: 99F |
| Low: 81F | Low: 82F | Low: 81F |
| Precip: None | Precip: 20% | Precip: 20% |
| New Orleans, LA | ||
| Saturday | Sunday | Monday |
| High: 91F | High: 90F | High: 87F |
| Low: 80F | Low: 78F | Low: 76F |
| Precip: 70% | Precip: 90% | Precip: 80% |
| Little Rock, AR | ||
| Saturday | Sunday | Monday |
| High: 99F | High: 92F | High: 95F |
| Low: 76F | Low: 73F | Low: 74F |
| Precip: 30% | Precip: None | Precip: None |
| Memphis, TN | ||
| Saturday | Sunday | Monday |
| High: 96F | High: 93F | High: 97F |
| Low: 74F | Low: 71F | Low: 76F |
| Precip: 30% | Precip: None | Precip: None |
| Birmingham, AL | ||
| Saturday | Sunday | Monday |
| High: 94F | High: 90F | High: 90F |
| Low: 74F | Low: 72F | Low: 74F |
| Precip: 90% | Precip: 40% | Precip: 30% |
| Atlanta, GA | ||
| Saturday | Sunday | Monday |
| High: 91F | High: 86F | High: 84F |
| Low: 73F | Low: 73F | Low: 71F |
| Precip: 80% | Precip: 70% | Precip: 70% |
