FXUS64 KOUN 212301 AFDOUN Area Forecast Discussion National Weather Service Norman OK 601 PM CDT Wed May 21 2025 ...New AVIATION... .KEY MESSAGES... Updated at 557 PM CDT Wed May 21 2025 - Shower and thunderstorm chances return on Thursday; strong to severe thunderstorms are possible. - Strong to severe thunderstorms remain possible Friday through Sunday. && .NEAR TERM... (Rest of today and tonight) Issued at 149 PM CDT Wed May 21 2025 Surface low pressure over far northwestern Oklahoma is expected to weaken and perhaps develop farther west this evening. The low and associated surface boundary is expected to drift southward tonight, as an upper air disturbance moves east across the central Plains. Meanwhile, a very moist airmass across the Gulf and Texas coast will begin to advect northward, especially this evening and overnight. Modest mid-level warm advection will likely result in increased cloud cover overnight, with an outside chance of elevated storms over central Oklahoma before 6-7 am Thursday. && .SHORT TERM... (Thursday through Friday night) Issued at 149 PM CDT Wed May 21 2025 CAM guidance is similar in developing elevated showers and storms mainly after 7 am. Parcels lifted from around 700 mb, yield about 750 J/kg per NAM soundings. Therefore, some of the stronger storms may produce some hail and maybe gusty winds. The mid-level flow is expected to be west to northwest, so storms will generally move to the east and southeast around 25-30 mph. Some models indicate convection may become more robust through the mid to late morning, as low level moisture continues to increase. If this occurs, the chance of severe storms will increase, mainly south of I-40 and east of I-35. By early to mid afternoon, a surface low is expected to be located across southwest Oklahoma and western north Texas with an associated front extending eastward across southern Oklahoma/ far northern Texas. Moisture pooling near the frontal boundary and strong heating, may result in rather high instability by late afternoon near the Red River Valley. Surface and low level winds are expected to be fairly weak, but the mid-level flow will be sufficiently strong and veered for at least isolated severe storms. Storms that form will move southeast, which should help with storm relative inflow. Large hail and damaging winds will be possible with the strongest convection. By mid evening, most of the convection is expected to be south of our western north Texas counties. A much stronger low level jet is expected to develop Thursday night with better mid-level warm advection across northern Oklahoma and western Kansas. This may be the more favored location for elevated showers and storms late Thursday evening/overnight. On Friday, surface winds will transition back to a southerly flow with a diffuse warm front lifting into central and northern Oklahoma during the afternoon and evening. A few dryline storms may develop by in the central/eastern Texas Panhandle late Friday afternoon. If storms form, a few may drift into far western Oklahoma and western north Texas during the evening. Friday evening into the overnight hours, scattered thunderstorms may form north of a surface warm front in Kansas and northeast Oklahoma. Some of this activity may move southeast into north central Oklahoma, but better chances appear north and east of our area. This activity will be elevated with the potential for large hail and maybe strong winds. && .LONG TERM... (Saturday through Tuesday) Issued at 235 AM CDT Wed May 21 2025 Concern for additional showers and thunderstorms will remain the main message as we head into Memorial Day Weekend. While the upper regime will trend towards an amplified upper ridge overhead, signal remains for embedded/low-amplitude systems to round the periphery of the ridge, perhaps close enough to support thunderstorm development. For now, greatest chances (30-50%) reside on Saturday evening and Sunday, mainly along and east of the US-81 corridor. While details on focused areas/threats of severe weather remain uncertain at this update, given the progged return of seasonable moisture, steep lapse rates and marginally sufficient deep-layer wind fields, this threat cannot be discounted and further refinement/focus will arrive over coming updates. Those with outdoor plans over the weekend should make sure to stay up to date with the forecast. Saturday looks particularly hot across the region, with a few locales across western-north Texas perhaps reaching 100-degrees during the late afternoon. A surface front will offer cooling conditions into Sunday (80s) before a potentially multi-day period in the 70s arrives by Monday. Ungar && .AVIATION... (00Z TAFS) Issued at 557 PM CDT Wed May 21 2025 Mostly VFR conditions will prevail through the period, outside of thunderstorm-induced MVFR ceilings. Thunderstorms are possible tomorrow morning across central and southern Oklahoma. Additional thunderstorms are possible tomorrow, but may stay south of the Red River. Will need to monitor trends in impacting TAF sites near and south of the Red River. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 59 78 57 80 / 10 30 30 40 Hobart OK 58 83 59 84 / 10 10 20 20 Wichita Falls TX 65 92 61 86 / 10 30 30 20 Gage OK 54 80 54 81 / 0 0 10 20 Ponca City OK 58 78 52 75 / 10 10 20 50 Durant OK 61 83 62 83 / 0 40 30 10 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$ NEAR TERM...06 SHORT TERM...06 LONG TERM....09 AVIATION...13