8:45 PM CDT | May 19, 2019
Yesterday, there were over 300 severe weather reports across the United States. The majority of these were in the South Central United States. Texas saw a total of 11 tornado reports with numerous reports of large hail and damaging winds. We saw a break today, BUT our next big weather-maker is on its way. The core of this system is currently in California, but it will make its way into New Mexico before sunset tomorrow. Ahead of the main system, a lead impulse will eject into the Texas and Oklahoma Panhandles late tonight/early Monday morning. This is where I will start...
As you can see above, there is a slight risk of severe weather tonight for the Texas Panhandle and parts of West Texas. The primary risk will be large hail followed by damaging winds late in the period.
A Severe Weather Outbreak is likely on Monday. There is a moderate risk of severe weather across the eastern Texas Panhandle and parts of Northwest Texas. An enhanced risk surrounds it and includes parts of the central Texas Panhandle, West Texas, and western North Texas. A slight risk surrounds that and so on... The activity late tonight will likely have merged into a larger cluster by daybreak. This activity will push east and northeast through the rest of the panhandle and into Oklahoma. The morning activity will have an impact on the environment and where the surface low/triple point (warm front to the east, cold front to the west, and dryline to the south) sets up as the day progresses. Thus, the area of greatest risk has the potential to shift around as things unfold.
Regardless, additional storms will form with daytime heating near and to the south and east of the triple point. The risk for severe weather will increase noteably for portions of Texas and Oklahoma by the afternoon. All hazards will be possible including the following:
1. Large Hail ranging from the size of quarters to softballs
2. Damaging Winds between 60 and 80 mph
3. Tornadoes - potentially strong
This will be round two. After sunset, this activity will begin to become more linear in nature as it shifts northeast across parts of the Texas Panhandle and Northwest Texas. Additional forcing will arrive from the west by mid-evening, leading to additional development in West Texas. We should see a quick transition to a squall line with an increasing risk for damaging winds. This activity will track east and northeast Monday night. The line is expected to lose some steam toward daybreak as the better forcing lifts northward into the Central Plains. While isolated severe storms will still be possible around I-35 by daybreak, it is also possible that the line "gusts out" as it near DFW early Tuesday morning. This means that rain-cooled air surges ahead of the line, cutting off the inflow of warm, moist air into the storms. The risk for strong winds would continue, but the storm intensity would drop off. Given the recent flooding in the Dallas-Fort Worth metro, this would be a good thing. Regardless, re-intensification of the line is likely in Northeast Texas later Tuesday. For this discussion, I want to focus solely on the period from tonight into Tuesday morning. Below, I have posted a loop from one of this afternoon's weather models. It shows the simulated radar from 7:00 AM Monday to 7:00 AM Tuesday. Please keep in mind that the radar will not look "exactly" as shown. The purpose of sharing this is to give you an idea of the general scenario. This particular model thinks that the squall line will weaken and "gust out" early Tuesday morning. Only time will tell...
One last thing I would like to note this evening concerns North Texans on Monday, particularly those north of I-20. The model guidance suggests that the cap will be weak over North Texas, including Dallas and Fort Worth. Ample instability and favorable shear will be in place by Monday afternoon. This would spell trouble, but most of the guidance shows the majority of North Texans storm-free Monday afternoon and early evening. Without a surface boundary to focus development, storm development would be associated with the low-level jet and a non-existent cap. If the cap is breached, then a few severe storms could develop with all hazards possible. BUT, if the cap remains at least somewhat intact (which is what the majority of the weather models suggest), then only some streamer showers would be expected. The evening weather models are just now arriving. If there is anything worth noting with the new data, I will share it on Facebook tonight.
Keep an eye on your forecast as adjustments can be expected. Not everyone at risk for severe weather will see severe weather. It does mean that the potential exists, especially across the moderate and enhanced risk areas. If you do not see any storms or severe weather, consider yourself very fortunate tomorrow. Remember, a watch means that conditions are favorable for the development of severe weather. A warning means that severe weather is imminent or is already occurring and to seek shelter immediately. More flooding can be expected, especially across the northwestern portion of the state. For the latest local weather information for your area, please visit the National Weather Service website. You can also find Texas Storm Watch on Facebook. To help make sure you do not miss any updates, LIKE the Facebook page and join the Facebook group. I will be posting periodic updates there as all of this unfolds.