Good morning, folks! No major changes are expected for the forecast this week, as we’re now in a more recognizable muggy-with-afternoon-thunderstorms setup – compared to the well-above average temperatures from last week.
First, let’s take a look at the synoptic picture to see what we’re working with, than we’ll dive into model data to see what the future holds…
Synoptic Picture
Overall, a fairly common 500mb map for this time of the year, with relatively uniform heights across the southern half of the country. Following the wind barbs, some moist air is continuing to be fed into the region due to a southerly flow off the Gulf of Mexico – once again, a fairly common for this time of year.
If we take a look at the precipitable water values across the region, we can really see just how moist the air is, with precipitable water values greater than 2″ for most of the area. As a result, just about any vertical motion in the atmosphere is enough to develop a thunderstorm with heavy downpours, as we’ve been seeing for the past few days.
It is interesting to note, however, the sharp moisture gradient present in the map above, with precipitable water values in the southeastern part of Arkansas as high as 1.7″, but in north-central Arkansas they’re as low as 0.6″! This is all thanks to an old boundary between a relatively drier airmass to the north and a moist tropical airmass to the south that inched southward earlier this week. Finally, though, the synoptic-scale southerly flow is helping to push some of the more moist air northward.
It was along this stalled-out boundary that enough vertical lift supported the development of a weak tropical disturbance in the northern Gulf of Mexico, which is partly responsible for relatively high precipitable water values across the region. This disturbance, which the National Hurricane Center designated as invest 95L, is being watched closely for the potential to develop into a tropical depression or a weak tropical storm before the center moves onshore in Eastern Texas – but at this time any further development looks unlikely, and it will only continue to be responsible for some showers or thunderstorms throughout the week.
What the Future Holds
As I’ve already alluded to, there isn’t expected to be much of a pattern change this week, with about average temperatures and an increased chance for showers and thunderstorms pretty much being the story for the next week.
Model guidance is in good agreement that that tropical disturbance off the Gulf Coast will continue to yield the threat for some some showers and thunderstorms as its disorganized center moves onshore Friday morning.
The one place where the 00z runs of the American and the European weather models disagree though, is where the remnants of this system end up by the weekend
We’ll start with the European model, which has the system coming ashore Friday in eastern Texas, and the upper-level circulation still sticking around by Saturday morning after having drifted eastward into Louisiana. As the image shows, it’s pretty disorganized, but nonetheless will still be responsible for enhancing our chances for rain.
What’s was left of the upper-level signature by Saturday morning has all but disappeared by early Monday, with only a strand of enhanced vorticity visible on the 500mb map. Once again though, the energy associated with this system will still help to increase our chances for rain throughout next week.
If we look at the GFS model though…
It still has a some-what defined circulation apparent on the 500mb vorticity map all the way through early Monday morning. But really, the most important thing to note is that this circulation is much farther westward than the ECMWF solution, which means it would bring more rain to southern Arkansas and eastern Texas. Regardless of the final resting place of this weak tropical system, the energy from this disturbance will continue to be responsible for rain throughout the beginning of next week.
Let’s not forget about our precipitable water values, though.
Throughout the entire week, neither model refuses to let the Deep South escape precipitable water values of less than 1.5″, with the values staying over 2″ most of the time. The images above are the American and European model outputs about a week from now, with the only differences being a slightly drier GFS, particularly across Central Florida.
To conclude, there really aren’t many dramatic changes with the weather this week. The remnants of the tropical disturbance drifting over the area and the abundance of moisture in the region will help to keep the chances for showers and thunderstorms relatively high throughout the next week, with temperatures expected to be about average as well.
Day-to-day Forecast
Thursday
A 95-percent chance of thunderstorms with peeks of sunshine possible at times. Expect high temperatures in the mid-80s.
Friday
Cloudy to mostly cloudy skies with an 80-percent chance of thunderstorms. Expect high temperatures in the mid-80s.
Saturday
Mostly Cloudy with a 70-percent chance of thunderstorms. Expect high temperatures in the mid-80s.
Sunday
Partly to mostly cloudy skies with a 70-percent chance of thunderstorms. Expect high temperatures in the mid-to-upper 80s.
Monday
Partly to mostly cloudy skies with a 70-percent chance of a showers or thunderstorms. Expect high temperatures in the mid-to-upper 80s.
Tuesday
Partly to mostly cloudy skies with a 70-percent chance of a showers or thunderstorms. Expect high temperatures in the mid-to-upper 80s.
Wednesday
Partly to mostly cloudy skies with a 70-percent chance of a showers or thunderstorms. Expect high temperatures in the mid-to-upper 80s.
