FXUS64 KOUN 210404 AFDOUN Area Forecast Discussion National Weather Service Norman OK 1104 PM CDT Sat Jun 20 2026 ...New AVIATION... .KEY MESSAGES... Updated at 1032 PM CDT Sat Jun 20 2026 - A Heat Advisory is in effect on Sunday for portions of the area, with heat index values up to 108 deg possible - An unsettled pattern with multiple rounds of rain/storms are expected over the next seven days; severe storms and heavy rainfall are possible on Sunday and Monday nights - Below average temperatures are forecast this upcoming work week && .NEAR TERM... (Rest of today and tonight) Issued at 203 PM CDT Sat Jun 20 2026 A mid-level shortwave trough, currently centered over Idaho, heads eastward throughout the near term period. The preceding height falls will aid in the deepening of the leeside surface low and an increase in SSE winds over northwest Oklahoma by afternoon as a quasi-stationary front over Kansas lifts slightly northward as a warm front. Maximum temperatures are expected to be in the upper-80's to low-90's. There is a low chance (less than 10%) of an isolated shower or thunderstorm over southeastern Oklahoma this afternoon. Storms are expected to develop over eastern Colorado and western Kansas by early evening with the approach of the upper wave. Chances of decaying convection reaching northwest Oklahoma tonight have generally decreased. However, if storms reach this area, large hail and damaging wind gusts are possible. Thompson && .SHORT TERM... (Sunday through Monday night) Issued at 203 PM CDT Sat Jun 20 2026 The aforementioned front begins to sag into northwest Oklahoma as a quasi-stationary cold front by mid-day but is not expected to make much forward progress during the day on Sunday. As a result, hot, muggy, and breezy conditions are expected with heat index values in the triple digits expected for many areas. A Heat Advisory has been issued for north-central to west-central to southwest Oklahoma and western north Texas with heat index values up to 108 deg possible. Our FA is expected to remain dry for most of the day. By late afternoon, strong to severe thunderstorms are expected to develop along the front across northern, and perhaps, western Oklahoma. At this time, the area with highest severe storm probabilities is northern Oklahoma (including Waynoka to Fairview to Enid to Perry), where large hail up to 2 inches diameter, damaging wind gusts of 70+ mph, and a very low risk of tornadoes, are possible. Locally heavy rainfall could also lead to flash flooding into Monday morning as the front moves very slowly southward into central Oklahoma. Rain/storm chances continue during the day on Monday and high temperatures will be below-average for much of the forecast area. Another round of rain and storms (along with heavy rainfall potential) are expected on Monday night into Tuesday morning. Thompson && .LONG TERM... (Tuesday through Friday) Issued at 230 AM CDT Sat Jun 20 2026 Northwest to west-northwest flow aloft will continue to be the synoptic-scale pattern across the Southern Plains as a mid-level ridge remains centered across the southwest U.S. into northern Mexico. With northwest flow aloft, an active weather pattern will continue into next week as embedded shortwaves pass by the Plains. As these waves pass by, there will be ongoing chances for showers and thunderstorms as MCSs and/or effective cold fronts advance southward. The highest chance for showers and thunderstorms will generally be in the overnight/early morning hours. These complexes of thunderstorms and their effective (i.e., convectively-reinforced) cold fronts should result in seasonable to slightly below normal temperatures next week. Mahale && .AVIATION... (06Z TAFS) Issued at 1032 PM CDT Sat Jun 20 2026 A thunderstorm complex coming down the Central High Plains could impact 3 of our terminals in northern Oklahoma through 12Z. As a result terminals KWWR, KPNC, and KSWO could briefly reduce down to an IFR category with a lowered ceiling and reduced visibility in rain although the latter two could stay in an IFR category due to stratus up to 15Z. Another storm system along a cold front passage will increase after 19Z across northern Oklahoma reaching the I-40 corridor by 01Z as 30% probabilities are in place at terminals KCSM and the Oklahoma City Metro (KOKC & KOUN). Surface winds currently out of the southeast but expected to veer more southerly by 12Z at 15 kts gusting to 20 kts. By 16Z south- southwest winds increasing 15-20 kts will gusting up to 30 kts as we start mixing higher into a low-level jet. At current time the low-level jet is strengthening out of the south increasing to 35 kts flow which could produce low-level wind shear across our terminals. A cold front will start pushing into northern Oklahoma between 00-03Z shifting surface winds out of the northeast behind it. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 73 95 73 86 / 0 0 70 40 Hobart OK 72 100 72 90 / 0 0 40 30 Wichita Falls TX 72 97 75 95 / 0 0 20 30 Gage OK 72 101 67 86 / 10 0 30 30 Ponca City OK 73 97 68 81 / 10 30 80 30 Durant OK 75 91 78 92 / 0 0 50 50 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...Heat Advisory from 1 PM to 8 PM CDT Sunday for OKZ005>008- 011>013-015>027-033>039-044-045. TX...Heat Advisory from 1 PM to 8 PM CDT Sunday for TXZ083>090. && $$ NEAR TERM...01 SHORT TERM...01 LONG TERM....10 AVIATION...68