textproduct: Norman

KEY MESSAGES

Updated at 540 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

(00Z TAFS) Issued at 540 PM CDT Sat Jun 20 2026

Expecting all but 4 of our terminals to remain in a VFR category throughout the entire forecast period. We may see some broken stratus increase across southeast Oklahoma toward mid-morning impacting only terminal KDUA between 11Z-16Z degrading that terminal to an IFR category due to a low ceiling. There is a 30% probability of storm activity coming down off the Central High Plains which could move into northern Oklahoma impact terminal KWWR between 02Z-06Z then eventually terminals KPNC & KSWO between 08-12Z. All 3 terminals could see brief periods of IFR conditions due to low ceilings although they may linger a bit longer to a near LIFR category through 15Z at terminals KPNC & KSWO.

Surface winds will back southeast this evening but start veering more southerly by 06Z as a low-level jet starts strengthening out of the south. Did add potential for low-level wind shear conditions with this moderate jet flow between 30-35 kts. Surface winds will continue to veer south-southwest at 15-20 kts gusting 20-30 kts by 15-16Z as we start late morning vertical mixing into the low-level jet. By 21Z surface winds at terminal KWWR should veer more westerly and lighten up just ahead of an approaching cold front.

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.