textproduct: Tulsa

KEY MESSAGES

Updated at 1049 PM CDT Wed May 20 2026

- Rain and thunder chances increase Thursday into Friday, and remain 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.

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

(06Z TAFS) Issued at 1210 AM CDT Thu May 21 2026

Poor aviating conditions will continue through much of the period at all sites except for perhaps FSM. Widespread IFR/MVFR ceilings continue this morning, with FSM and BVO currently being the outliers with unrestricted ceilings. Conditions will deteriorate further after sunrise for the NE OK sites and afternoon for MLC and the far NW AR sites with expected development of widespread rain with embedded thunderstorms. This will approach FSM late afternoon and early evening with long duration impacts there less certain. The main adjustments from the previous set of TAFs have been to speed up the arrival of this activity at each site and also to include a mention of thunder at MLC/FSM. A similar explicit mention may need to be included in either amendments or the 12Z set of TAFs at the NE OK and far NW AR terminals, depending on observational and model trends. Winds will be light through the period and mainly from the east to northeast.

PRELIMINARY POINT TEMPS/POPS

TUL 62 78 62 80 / 90 50 50 30 FSM 65 80 63 84 / 70 70 30 40 MLC 63 81 63 81 / 80 20 50 60 BVO 58 78 57 79 / 80 50 50 40 FYV 62 75 60 82 / 80 70 30 50 BYV 61 73 59 81 / 60 80 20 40 MKO 62 78 61 80 / 90 50 40 50 MIO 61 75 59 79 / 90 70 30 30 F10 61 79 61 80 / 90 20 50 40 HHW 63 81 64 81 / 80 20 50 60

TSA WATCHES/WARNINGS/ADVISORIES

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