It is looking possible that I’ll be chasing in Arkansas on Sunday. If you’re not a weather-weenie then I would go ahead and skip the rest of this post. It will contain some weather jargon that would bore most of our audience. A compact and fast-moving upper level disturbance will move into Arkansas during the afternoon hours. Southeasterly surface winds during the day will help increase surface dewpoints into the lower 60s. Surface temperatures look to warm into the lower to middle 70s by peak-heating. The atmosphere will become moderately unstable with most unstable CAPE values approaching 1500 to 2000. CAPE stands for Convective Available Potential Energy which is a long way of saying the amount of instablity available to a thunderstorm. CAPE Values over 1000 are usually favorable for organized thunderstorms if other ingredients are in place. Wind shear values will be favorable for organized convection. Winds at 500 millibars (~18000 feet ASL) will be out of the west/southwest at over 75 MPH. Winds at 850 millibars (~5000 feet ASL) are forecast to be out of the southwest at 35 to 50 MPH. Surface winds are expected to be out of the southeast at 15 to 20 MPH. The amount of low-level wind shear will be on the marginal size for sustained tornadic activity. However there are mesoscale factors such as any boundaries or topographical features that may locally enhance low level wind shear. Those factors, should they materialize, won’t be clear until storms are underway. Large hail certainly is the most likely hazard from the strongest storms tomorrow. The unstable airmass along with cold temperatures aloft will promote some hailstones over the size of golfballs. Localized damaging wind gusts will also be a possibility. Our friends at the National Weather Service in Little Rock have put out a graphicast showing the risks for Sunday. Fortunately for Texas a majority of the thunderstorm activity should be east/northeast of Texas. We’ll have to watch for thunderstorm development in extreme Northeast Texas tomorrow afternoon. One or two storms may become strong around Texarkana before moving into Arkansas. My chase target would be around Little Rock and points east simply due to more favorable terrain. Western Arkansas is extremely hilly and contains tall trees. Those trees make chasing very difficult and more dangerous. If the storm system slows down then storms may end up being in western Arkansas. I would likely cancel the chase since I dread chasing in that part of Arkansas. We’ll have to wait and see what happens tonight. As of this afternoon I’m 75% sure I’ll be chasing on Sunday. Should things go well I will have a live stream up on YouTube once we’re on a storm.