textproduct: Norman

KEY MESSAGES

Updated at 1218 PM CDT Thu May 21 2026

- Showers and thunderstorms and cool temperatures are expected today; locally heavy rainfall is possible.

- Strong to severe thunderstorms are possible on Friday afternoon and Friday night across western Oklahoma and adjacent north Texas.

- Rainy pattern continues through middle of next week.

NEAR TERM

(Rest of today and tonight) Issued at 1218 PM CDT Thu May 21 2026

Episodes of rain and thunderstorms will continue for the rest of the day today and into this evening. The primary drivers of convective activity will be two features that can be seen on regional radar/satellite:

1) A subtle MCV lifting northward near or just west of I-35 from Texas through Oklahoma

2) The broader trough axis within the subtropical jet

The first of these will continue to move northward during the day with localized clearing increasing instability to about 1,000-1,500 J/kg of MLCAPE. The exact triggering mechanism near or behind the MCV is uncertain, and may contribute to a rather scattered "popcorn" nature of storm redevelopment. Because of that, rainfall totals will vary greatly from point to point, with some spots maybe seeing little to no rain (especially west of I-35), and a couple of locations seeing 2-3 more inches. The second area's impact is less certain, as several CAMs suggest an eastward rather than northeastward progression of the storms in west Texas. However, it still appears that showers and thunderstorms will be possible across western north Texas this afternoon as the trough inches north.

Chances for rain will decrease across much of the area tonight as the environment begins to stabilize. The exception will be in northwest Oklahoma, where a complex of thunderstorms is expected to move in between 10 pm and 3 am after developing on the Raton Mesa. While modest instability will continue into our area, the lack of a low-level jet should commence a weakening trend with these storms as they arrive in northwest Oklahoma, and they will decay before long.

Meister

SHORT TERM

(Friday through Saturday night) Issued at 1218 PM CDT Thu May 21 2026

Our CWA will continue to be squeezed between the polar and subtropical jets tomorrow as the northern stream becomes the dominant weather driver. Because of this, and with the 500 mb jet streak in the eastern Dakotas, a cold front will ooze southward into northern/western Oklahoma. Return flow ahead of the front will be fairly nondescript, but sufficient instability and mesoscale forcing should exist for storm development in the central panhandles. The most likely scenario at this point seems to entail a cluster of storms moving in during the late evening into early overnight hours near or just north of the boundary. The severe risk will likely peak rather early in the overnight period with at least some damaging wind/hail potential, but dosn't look overly impressive for significant severe weather. Frontal undercutting will occur later in the night, but it is noteworthy that almost all CAM guidance maintains at least some semblance of an MCS across the entire CWA overnight despite the lack of a LLJ again.

The frontal boundary will continue to leak southward on Saturday. Rain/storm chances will continue during the day but should not lead to any sort of focused severe/flood risk. Meanwhile, temperatures will begin to rebound (even behind the front) to get closer to normal for this time of year. Most spots will hit about 80 during both days in the short term with at least some breaks in the cloud cover.

Meister

LONG TERM

(Sunday through Wednesday) Issued at 247 AM CDT Thu May 21 2026

A weak closed upper low is forecast to develop over north Texas and bring continued shower and thunderstorm chances Sunday through possibly Wednesday. While temperatures could rise to near seasonable, it appears it will be relatively cool as we go into middle of next week with highs in the low 80's.

Thompson

AVIATION

(12Z TAFS) Issued at 630 AM CDT Thu May 21 2026

IFR to LIFR flight conditions are ongoing this morning and will likely persist at most terminals through the TAF period with low ceilings. KSPS and KWWR are the most likely terminals to briefly see MVFR flight conditions before conditions deteriorate again tonight.

Rain with some embedded thunderstorms will continue to move to the northeast through the day with chances gradually ending from west to east. Drizzle and mist is still possible even when the rain exists.

Mahale

PRELIMINARY POINT TEMPS/POPS

Oklahoma City OK 58 78 60 78 / 40 10 70 50 Hobart OK 57 81 58 80 / 20 10 70 50 Wichita Falls TX 59 83 60 82 / 30 10 70 40 Gage OK 54 77 52 76 / 30 40 70 60 Ponca City OK 58 78 58 78 / 50 20 50 40 Durant OK 63 82 64 82 / 80 20 50 60

OUN WATCHES/WARNINGS/ADVISORIES

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