The Day 4 area shows where storms could be on Sunday and Sunday night while the Day 5 area depicts where storms could be Monday and Monday night. There could be a threat beyond this Day 5 area further to the east but at this time there are too many uncertainties about the track of the system to really be able to pinpoint an area at risk for severe storms.
Above is where the storm system is expected to be on Monday morning. Most of the current model runs are showing that the main risk for severe storms would not start until Sunday late afternoon into the evening. That being said, areas just to the east of the dry line would be at the greatest risk for these storms. The cold front should take over the dry line by Tuesday morning and continue to push very slowly to the east, potentially only reaching central Texas by Wednesday morning. So what will be aiding these storms?
Taking a look at the GFS model run depicting what could be happening around midday on Monday, the first thing to consider is a very large trough which will be centered just to the west of the severe storms areas. This trough will help aid in some very strong winds aloft with a very large jet streak occurring over the surface cold front and dry line helping to enhance shear.
Additionally, 850 mb winds out of the south will help aid in bringing warm and moist air into the area. Although the warm air advection does not look that good for all areas, most of these areas will also benefit from the warm air that was already in place thanks to this week’s above normal temperatures. An 850 mb low level jet should also aid the storms, especially north of Texas.
The warm and moist air will be evident along with south to southeast surface winds which will be stronger near the front. Dew points greater than 60 will be widespread in front of the frontal system with dew points greater than 65 across most of eastern Texas. This should provide for a conducive environment for severe storms.
Additionally, CAPE values should be quite high with the GFS model forecasting 1000 plus CAPE values over much of eastern Texas and some parts of eastern Oklahoma. This should be some of the best CAPE we have seen so far this severe weather season.
This is surely an event to keep an eye on as it gets closer. People who live in the Plains from Texas into Nebraska should be alert for future forecasts about this event as well as people who live downstream into the Midwest and southeast as this event could eventually make its way into these areas later on in the week.