textproduct: Norman

KEY MESSAGES

Updated at 538 PM CDT Sun Jun 21 2026

- An unsettled pattern with multiple rounds of rain/storms are expected over the next several days; severe storms and heavy rainfall are possible on tonight and Monday nights. - Below normal temperatures are forecast this week and heat up next weekend.

NEAR TERM

(Rest of today and tonight) Issued at 204 PM CDT Sun Jun 21 2026

Hot and humid conditions continue this afternoon with breezy SSE winds. Latest surface observations show a surface low centered over the Oklahoma panhandle and the remnant outflow boundary from this morning's storm complex has largely mixed out and has shifted across northern Oklahoma as indicated by the return to SSE winds and rebounding dewpoint temperatures. The synoptic stationary front remains in Kansas and is rather diffuse, and may not push into Oklahoma until late tonight or early Monday morning with the momentum of the high plains convection. Until then, low-level frontogenesis ongoing over portions of northwest and northern Oklahoma appear to be the focal zone for initially discrete supercell thunderstorm development later this afternoon and into this evening as dynamic ascent increases ahead of a subtle mid-level shortwave.

A highly unstable airmass near the boundary (3500-4500 J/kg of MUCAPE), mid-level lapse rates increasing to near 8C/km, and decreasing CIN, along with high DCAPE will lead to large to very large hail potential initially with the discrete storms that develop over NW/N Oklahoma as early as late afternoon (up to the size of tennis balls). Evolution of storms tonight is somewhat uncertain given the variance among model outputs. However, storms are expected to form a complex by late evening and overnight with damaging wind gusts probable with these storms with isolated gusts of 75+mph possible. There is also a very low risk of tornadoes, primarily over north-central Oklahoma late afternoon and evening in proximity to the boundary. However, we cannot rule out a tornado overnight as the complex drops southward. The complex of storms is anticipated to move through central Oklahoma sometime between the pre-dawn hours and rush hour on Monday (though timing is also uncertain).

In addition to the severe hazards, flash flooding could be an issue as well with rainfall rates of 1 to 3 inches per hour possible.

Thompson

SHORT TERM

(Monday through Tuesday night) Issued at 204 PM CDT Sun Jun 21 2026

As mentioned above, the risk of severe thunderstorms (all hazards possible) continues on Sunday night into Monday morning and storm redevelopment late Monday will depend on how tonight's event unfolds. Given the anticipated potency of tonight's storms, we suspect severe risk will be low on Monday afternoon for much of the area, with the exception of southwest Oklahoma into western north Texas. Instability increases across the area on Monday night and another round of thunderstorms with heavy rainfall is expected on Monday night into Tuesday morning. Storm chances continue, to a lesser extent, during the day on Tuesday. High temperatures will range from the low-80's (northern OK) to 90's (southern OK and north TX) on Monday and Tuesday.

Thompson

LONG TERM

(Wednesday through Saturday) Issued at 240 AM CDT Sun Jun 21 2026

Northwest to west-northwest flow will continue to persist across the Southern Plains through at least Friday with a mid-level ridge remaining quasi-stationary across the southwest U.S into northern Mexico.

With northwest flow aloft, an active weather pattern will continue as embedded shortwaves within the flow move across 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. With respect to location, the highest chances will be across northern Oklahoma with decreasing chances with southward extent. These complexes of thunderstorms and their effective, convectively-reinforced cold fronts should result in seasonable to slightly below normal temperatures.

By the late into the upcoming weekend into next week, deterministic and ensemble data indicate a mid-level ridge may strengthen to our east. This would result in hotter and drier weather across the Southern Plains.

Mahale

AVIATION

(00Z TAFS) Issued at 538 PM CDT Sun Jun 21 2026

Two rounds of storms may impact our terminals through the forecast period degrading our terminals for periods to an MVFR to IFR category with lowering CB ceilings and reduced visibilities in heavy rain at times. The first round of strong to severe convection will be along a cold front & mid-level shortwave coming down the Central Plains expected to start pushing into northern Oklahoma around 03Z and reaching terminals near the I-40 corridor around 07Z and eventually crossing the Red River into terminal KSPS by 09Z. A second round of storms will be in association with a second mid-level shortwave coming off the Southern High Plains which may impact our terminals again from 12-18Z. Due to some uncertainties with timing did extend lower probabilities of 30% for storms beyond 18Z. Surface winds will shift northeast behind the cold front but in actuality expecting surface winds to be gusty and variable in direction due to the convection and outflow from the storm activity.

PRELIMINARY POINT TEMPS/POPS

Oklahoma City OK 72 85 68 86 / 70 60 70 50 Hobart OK 72 90 68 92 / 40 40 70 10 Wichita Falls TX 76 95 72 95 / 20 30 60 10 Gage OK 67 84 64 89 / 60 40 40 20 Ponca City OK 68 81 65 83 / 70 20 50 30 Durant OK 78 92 75 91 / 50 50 60 40

OUN WATCHES/WARNINGS/ADVISORIES

OK...Heat Advisory until 8 PM CDT this evening for OKZ005>008-011>013- 015>027-033>039-044-045.

TX...Heat Advisory until 8 PM CDT this evening for TXZ083>090.