Good Morning,

Another day, another chase. Hard to believe this is October. Anyway, Today should be the final day of chasing before everything shifts off to the east, so lets make the most out of it!

9:40 AM Visible Sat

Morning visible satalitte shows the warm sector mostly clear this morning. The band of clouds over the metroplex is mainly from condensated moisture from yesterday’s rain. The area of interest is clear and temperatures are warming nicely.

By 4 PM this afternoon, a 500 MB jet with at least 45 knots of wind will be over the southern and eastern portions of North Texas, eastward into the woodlands known as chaser hell. This is a very favorable setup for severe thunderstorms.

As I stated last night, instability today will be much higher then the previous two days. As of 9 AM, Instability across parts of East Texas was already above 2,000 J/kg. The RUC (Rapid Update Cycle) is showing over 3,000 J/kg by this afternoon and that is a reasonable assumption. Based on current trends, the dryline should be over, or just east of Dallas by this afternoon. Any convection should affect areas east of I-35. With the increased instability and mid-level lapse rates, very large hail will become more common today. By that I mean I’m not going to be surprised to hear several reports of at least baseball sized hail by this afternoon.

Two high resolution models, the RUC and HRRR, are showing convection in nearly the same location by 4 PM this afternoon. While the locations are off I’m sure, the general idea of some sort of convection initiating around the Athens-Tyler idea makes me believe that is the best place to head. My plan is to leave Dallas by noon for an initial target of Athens, Texas. The road network is good so I will be able to adjust from there, if necessary. Today’s storms should be moving in an east, or northeast fashion at about 30-35 MPH. Main threats will be damaging hail, but with a couple boundaries in place, the potential is there for one or two tornadoes. Low level shear is more veered then yesterday, so the tornado threat is lower, but the boundaries could help enhance 1 KM SRH in localized areas. Either way, you’re not going to want to mess with the supercells this afternoon, as they will take advantage of the higher instability and shoot out monstrous hail.

As with the previous two days, the live stream and GPS will be up this afternoon when I hit the road. I appreciate all the feedback we’ve been getting on our facebook and twitter pages. Although I generally am unable to view those until I get back home, it’s nice to see that so many people are following along! I’ll try to provide several updates throughout the day. Thanks for stopping by!

- David

Is this sounding like a broken record yet? I swear I’ve been writing these discussions for days now. We have one more day of severe weather on tap before things finally clear out and calm down, but don’t think the quietest day will be last. Looking at data tonight, it looks like tomorrow will be quite active in the eastern portions of North Texas.

Surface Dewpoints - 7 PM Friday

For Saturday’s severe weather event, a shortwave crossed the area, which helped convection get going. The dryline was not an active player in today’s convection, however, by Sunday it will become one of the primary players. The 0Z NAM tonight has a surface dryline over the Metroplex by 1 PM Sunday Afternoon. By this (Sunday) evening it has it stalled out just east of Dallas. Dewpoints behind the dryline will fall into the 40′s, while remaining in the 60′s ahead of the dryline. Unlike the past two days, sunny skies will prevail over the area, with the exception of morning fog. This will allow surface temperatures to warm into the upper 70′s to lower 80′s.

Surface Based Instability - 4 PM Sunday

Thanks to the increased heating, Instability will be much higher Sunday then it has previous days. On Saturday, SBCAPE values were just above 1,000 J/Kg. On Sunday, these values will likely be at or just above 3,000 J/Kg. This will allow for more of the ‘spring’ time supercells to develop. In addition, mid-level lapse rates will be steeper. This will promote very large hail, in some chases, over baseball size. That will be the main and most common threat tomorrow. In addition, the cap will be a little stronger on Sunday, thus allowing for a little more heating before convection initiates.

500 MB Winds - 7 PM

Upper level winds will continue to support severe thunderstorms on Sunday. The highest area of 500 MB winds will be south and east of Dallas by the afternoon hours, and that is where the focus will be on the potential for severe weather. With the dryline pushing east to the metroplex by late morning, areas along and west of Fort Worth should have a sunny, dry, and very warm day.

The low level jet will be slightly weaker on Sunday. That combined with the veered flow out of the southwest would tend to limit the tornado potential, however, today’s convection threw a little kink in that. Thanks to today’s convection, several outflow boundaries are located across North Texas. The models are unable to pick up on these, and in localized areas, the flow could back to the southeast. This would tend to elongate the local hodographs and help increase the tornado potential. The primary severe weather hazard will be hail, but in localized areas, conditions will be favorable for Isolated Tornadoes once again. Due to the higher instability, Sunday’s supercells could be more potent in terms of the hail threat, but the veered low level flow will help keep the tornado potential in check. Saying that, there will be a tornado potential, but not a widespread one. Thunderstorms should begin to fire in the early afternoon along the dryline, or around I-35. These storms will move eastward and will likely be severe, possibly supercellular in nature.  Definitely stay tuned, as any changes in the low level flow could greatly alter the setup on Sunday.

- David

At this point, I could write a forecast discussion and get all technical about tomorrow, but I’m tired and it’s going to be a long day. So lets make this nice and short so I can get some rest for tomorrow’s chase.

Saturday will have a greater potential for severe weather then Friday did across North Texas. Unlike Friday, a source of thunderstorm ignition will be present, and conditions will actually be more favorable for severe weather, with 55+ knots at 500 MB and a 35 knot Low Level Jet, both clusters of severe thunderstorms, and supercells will be possible. The main threats will be damaging wind (60+ MPH) and severe hail (1.00+ Inches). If we get a few discrete storms during the afternoon then an isolated tornado or two will be possible. All of North Texas is in the severe weather risk, along with parts of Oklahoma and Kansas. My plan is to once again chase in North Texas again Saturday.

Stay tuned to the social media feeds for the latest, just like Friday!

- David