textproduct: Tulsa

KEY MESSAGES

Updated at 759 AM CDT Thu May 21 2026

- Rain and thunder chances increase today and linger into Friday. There are rain chances forecast daily into the first half of next week with periods of heavy rain.

- Abnormally cool weather is expected Thursday, with a slow warming trend then developing into next week.

UPDATE

Issued at 759 AM CDT Thu May 21 2026

Morning surface analysis and model soundings still indicate some lingering shallow cool air at the surface over the northern and western portions of the forecast area, while some erosion of the shallow cool wedge has occurred over the southern and eastern portions. Looking aloft, SWrly flow prevails aloft, though not super strong (~25kts at 500mb). A feature of interest for the forecast today is located near the Red River in the vicinity of Wichita Falls. An area of low pressure is clearly evident on radar mosaic in this region, and the HRRR lifts this system slowly to the north and northeast today. Expect an increase in showers and thunderstorms especially as we go into the afternoon in advance of this feature across eastern OK and far northwest AR. Cloud cover will limit heating and destabilization over the region, and deep layer shear is not particularly strong. These factors suggest that the severe weather risk is fairly limited today. However, pockets of locally heavy rainfall could lead to isolated flash flooding, especially if slow-moving storms can train over the same areas. For the forecast highs today, this forecast will lean heavily toward the cooler side of the guidance envelope (CONSMOS, CONSShort) with the cloud cover and rain, with the model blend (NBM) consistently near the warmest side.

Lacy

SHORT TERM

(Through Thursday) Issued at 1049 PM CDT Wed May 20 2026

An upper level trough will dive into the area today (Thursday). As it does so, a mid level circulation will track west-east across Oklahoma and into Arkansas. Good convergence in the 850-700 hPa layer and modest diffluence aloft will act on a very moist airmass (PWAT ~1.6 inches) and MUCAPE of around 500-1000. This will be sufficient for widespread showers and thunderstorms to develop. Severe weather is not expected, rather, heavy rain is likely the greatest concern. Most areas will see somewhere between 0.5 and 2 inches of rain, though locally higher totals are possible. Localized flash flooding or river flooding may occur depending on the actual rain rates and where they occur. In terms of timing, precipitation will spread into eastern Oklahoma during the late overnight hours, slowly moving east. It should arrive into northwest AR and portions of southeast OK by around noon, spreading into the remainder of the area by the early afternoon. Precipitation will be ongoing into Friday. Highs Thursday will remain well below normal, with mid 60s to mid 70s across the area.

LONG TERM

(Thursday Night through Wednesday) Issued at 1049 PM CDT Wed May 20 2026

Precipitation will gradually wind down by Friday afternoon but any break will be short lived as another shortwave approaches late Friday into Saturday. This is expected to kick off another round of showers and thunderstorms, particularly for eastern Oklahoma. Models disagree on how far east it will move before weakening, as well as coverage and intensity. But at a minimum, at least scattered showers and storms are possible. Temperatures will also begin to warm with highs into the upper 70s to low 80s Friday and Saturday. One final shortwave will impact the area late Saturday or Sunday. Models are again uncertain on the details, but overall the ensemble signal for rain is a bit better than the Saturday morning system. Similar to the previous few systems, severe weather is not expected. After these three rounds of rainfall, river level rises would be expected, so this will be something to monitor.

Early next week, the upper level low will likely settle to the south across Texas. This will keep moist easterly flow wrapping into the area, with at least a daily chance of showers and storms. However, forcing will be less noticeable at the surface, so precipitation may just remain confined to the higher terrain in the southeastern parts of the forecast area. Temperatures will rise to near seasonal norms.

Another upper level low will move into the area from the northwest towards the middle of next week, interacting with the lingering upper level low to the south. Although guidance is all over the place with the details, this pattern looks quite similar to what we will be seeing the next few days. So presumably this would result in additional rounds of showers and thunderstorms and flooding potential, but not necessarily much in the way of severe weather. Details will become more clear as we get into early next week.

AVIATION

(12Z TAFS) Issued at 539 AM CDT Thu May 21 2026

Showers and occasional thunderstorms have developed near I-35 this morning, with their nearest approach to BVO so far. A more consistent area of thunderstorm activity has also developed in western Oklahoma. Further expansion in both areas of showers/storms and eventual eastward movement into eastern Oklahoma remains expected this morning and into western Arkansas this afternoon/early evening. While isolated lightning will remain expected through the morning hours, a better potential for lightning impacts will occur this afternoon and at FSM, this evening. Either PROB30 or TEMPO groups will be included at all sites with this TAF set for the highest confidence window. IFR conditions will continue through the period at the NE OK sites, with MLC seeing only a brief period of improvement to MVFR. The W AR sites should see improvement to VFR this afternoon given both humidity progs and model forecasts before ceilings reduce again during the evening/early Friday morning.

PRELIMINARY POINT TEMPS/POPS

TUL 71 62 78 62 / 100 90 50 50 FSM 79 65 80 63 / 30 70 70 30 MLC 75 63 81 63 / 80 80 20 50 BVO 69 58 78 57 / 90 80 50 50 FYV 75 62 75 60 / 70 80 70 30 BYV 75 61 73 59 / 40 60 80 20 MKO 74 62 78 61 / 90 90 50 40 MIO 72 61 75 59 / 70 90 70 30 F10 71 61 79 61 / 90 90 20 50 HHW 77 63 81 64 / 50 80 20 50

TSA WATCHES/WARNINGS/ADVISORIES

OK...None. AR...None.