textproduct: Norman

KEY MESSAGES

Updated at 540 AM CDT Sat Jun 20 2026

- Strong to severe storms possible this evening into tonight across northern Oklahoma.

- Hot temperatures return Sunday afternoon with widespread triple digit heat indices.

- Strong to severe storms are possible along a cold front late Sunday afternoon and evening.

NEAR TERM

(Saturday through Saturday night) Issued at 230 AM CDT Sat Jun 20 2026

Patchy fog is possible this morning with light east-southeast winds, high relative humidity, and clear to mostly clear skies for most locations.

An MCV (mesoscale convective vortex) across northeast Texas will result in a low chance of showers/storms across southeast Oklahoma today on its northwest periphery. Otherwise, most locations will remain dry during the daytime. Warmer weather is forecast with more sunshine and a return to southerly winds with highs ranging from the mid 80s to mid 90s deg F (seasonable for mid-June).

An MCS (mesoscale convective system) will develop east of the Rockies across the Central Plains this afternoon into this evening. The MCS is expected to move generally to the east with the most intense part moving across Colorado, Nebraska, and Kansas. However, the MCS will likely build as far south as the Oklahoma and Texas panhandles. As a result, the remnants of this complex may impact northern Oklahoma tonight as it weakens. The primary hazard will be damaging wind gusts.

Mahale

SHORT TERM

(Sunday through Monday night) Issued at 230 AM CDT Sat Jun 20 2026

Hot weather returns Sunday afternoon as the low-level thermal ridge expands eastward and strengthens ahead of an approaching cold front with veered low-level flow. High temperatures are forecast to be in the mid 90s to low 100s deg F with heat index values above 105 deg F for most locations. A Heat Advisory will likely be needed for much the area. A tightening surface pressure gradient will result in breezy southerly winds ahead of the cold front, which should at least temper the wet-bulb globe temperatures (WBGT).

By late afternoon into the evening, the cold front is forecast to advance into northern Oklahoma. A highly unstable air mass is forecast to develop ahead of the cold front with ~3000 to 4000+ J/kg of MLCAPE. Combined with ~35 to 40 knots of effective bulk shear, the environment is sufficient for strong to severe thunderstorms. Timing for convection initiation remains a bit uncertain with the strongest synopic-scale forcing not approaching from the west until the evening hours. However, given the magnitude of instability, low-level convergence along the cold front might be sufficient for at least some thunderstorm development before the more appreciable ascent approaches.

Showers and thunderstorms are expected to continue and become more widespread Sunday night (even north of the cold front) with a strengthening low-level jet resulting in continued isentropic ascent/warm air advection.

Monday's weather will be highly dependent on how far south the effective, convectively-reinforced cold front advances Sunday night. Showers and thunderstorms will likely develop in close proximity to the cold front during the day Monday. Increasing isentropic ascent/warm air advection Monday night will likely further increase shower/thunderstorm coverage near and even north of the boundary.

Mahale

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

(12Z TAFS) Issued at 540 AM CDT Sat Jun 20 2026

Satellite and surface observations show the onset of a stratus deck is ongoing across much of the area. Durant is currently a bit of an outlier with visibility near 1 mile, but Enid and Ardmore are also showing a fog signal. Fog this morning will be extremely localized but could also be quite dense in scattered localities. Based on latest observations and model trends, expect the stratus to last at least through noon in spots before ceilings begin to raise.

Meister

PRELIMINARY POINT TEMPS/POPS

Oklahoma City OK 88 73 96 71 / 0 0 0 70 Hobart OK 91 73 101 72 / 0 0 0 40 Wichita Falls TX 90 73 98 76 / 10 0 0 20 Gage OK 92 73 102 66 / 0 30 10 20 Ponca City OK 87 74 97 67 / 0 20 40 60 Durant OK 88 75 93 78 / 10 10 0 50

OUN WATCHES/WARNINGS/ADVISORIES

OK...None. TX...None.