textproduct: Norman

KEY MESSAGES

Updated at 626 PM CDT Sun Apr 12 2026

- This week will continue to feature an active pattern with chances for showers and storms most days, some strong to severe.

- Elevated to near critical fire weather conditions will return early this week, especially across portions of northwestern Oklahoma.

NEAR TERM

(Rest of today and tonight) Issued at 232 PM CDT Sun Apr 12 2026

Attention will be turning in the near-term from this morning's round of showers to the conditional risk of thunderstorm development in the afternoon.

The MCV-aided wave's departure has veered out the surface winds across much of our area, which is usually coincident with subsidence. However, traditional early wave passages are also accompanied by more widespread cirrus than this one was, which will allow the dryline to heat up toward convective temperatures this afternoon. Thanks to those veered winds, confidence is high that the dryline will reside from near Knox City north-northeastward toward Medford by late afternoon. Morning model guidance depicts a very weak impulse reaching northwest Oklahoma by this point, which has the potential to counteract the subsiding effect of the early morning impulse's departure. Still, any updrafts that attempt to form will be fighting against unfavorable synoptics and an unfavorable orientation for the dryline circulation with minimal surface convergence.

For those reasons, storm chances this afternoon and evening remain extremely conditional. Most (potentially all) people in our forecast area will not see rain this evening. But if a couple of storms do manage to develop along the dryline and persist into the warm sector, they will encounter an environment favorable for multicell clusters and supercells, with about 30 knots of effective shear and 2,000+ MLCAPE. Large hail with more persistent updrafts and damaging winds with collapsing cores would be possible. The tornado threat looks to be rather marginal (but not completely zero) as the LLJ ramps up north of I-40, counteracted by a consistent modeled signal for capping building rapidly back in.

Overall: a low chance of storms, but a reasonable chance for severe weather if any form.

We will have a much warmer overnight period than normal across the area thanks to a northwestward slosh of the dryline.

Meister

SHORT TERM

(Monday through Tuesday night) Issued at 232 PM CDT Sun Apr 12 2026

Dryline placement tomorrow will look eerily similar today, potentially an echo of the rainfall gradient we've seen in western Oklahoma over the last month or so. The dry side of the gradient in northwest Oklahoma received about 1/4 inch of rain on average this morning - enough to wet the fuels, but not enough to soak them or to initiate green-up. Therefore, with warm and breezy conditions in the dry regime tomorrow, a Fire Weather Watch has been issued for north on the anticipation of dewpoints falling into the upper 20s and a low-level thermal ridge heating air temperatures into the upper 80s. The primary limiting factors for fire weather will be the rainfall further to the south and east as well as wind gusts that are breezy but by no means insane by the demanding standards of April on the southern Plains. Uncertainty is higher in the existence/placement of elevated to near-critical fire weather on Tuesday because a stronger wave approaches, increasing potential for the dryline to slosh westward. At the moment, though, the northwest corner of Oklahoma looks to continue with active fire weather through Tuesday.

On the other side of the dryline, storm chances are conditional both Monday and Tuesday, though of the two it would appear the latter has a greater chance to see convection development. Tomorrow, there is a signal on some of the less-mixed CAMs for a dryline bulge to emerge in southwest/west central Oklahoma just as a subtle increase in 500 mb flow overspreads the area from the west. With that said, it is noteworthy that of the remotely trustworthy CAMs, the 3km NAM is the only one to resolve any convection during the evening, and even the RRFS isn't resolving anything. The SPC has recently downgraded the convective outlook from our area from level 2 of 5 to level 1 of 5 because of the decreased confidence in storms on Monday. Cavea: the environment is more favorable for severe storms tomorrow than today were something to develop.

On Tuesday, a more robust wave will eject into the central Plains in the afternoon hours. Our forcing looks to be rather glancing, but the NAM does show steady if unremarkable 500 mb height falls of about 2 meters/hour. Convection-allowing guidance is more robust (though still far from assured) in showing the development of storms along the dryline in the evening. Profiles would strongly favor supercells capable of tornadoes, very large hail, and damaging winds were this scenario to occur.

Meister

LONG TERM

(Wednesday through Saturday) Issued at 134 AM CDT Sun Apr 12 2026

The actual trough axis will swing across the Plains Wednesday and the dryline will mix slightly more eastward, but storms will remain possible east of the dryline, mostly across central into eastern Oklahoma. Details on timing and hazards will be refined over the next few days with a better understanding of the upper troughs progression. Fire weather may also be possible west of the dryline, but again will remain highly conditional on rainfall earlier on in the week.

The active pattern does not come to an end after the wave passes Wednesday. Another system will dig into the Pacific northwest Thursday and keep southwesterly flow aloft. Thus, daily storms chances remain for the end of the week and into the weekend. Details on timing, location and severity will continue to be ironed out once the first wave moves through. Fire weather concerns during this time will also remain dependent on the dryline positioning and rainfall that occurs through the week.

AVIATION

(00Z TAFS) Issued at 626 PM CDT Sun Apr 12 2026

Prob 30 thunderstorm chances have been added for KCSM, KLAW, and KSPS this evening as a few storms have developed over the Texas panhandle. There is considerable uncertainty as to whether the storms will persist this evening, but the main hazards are strong wind gusts. Also, LLWS is a concern late tonight into Monday morning for a few terminals. MVFR ceilings are anticipated to spread north/west tonight with ceilings lifting by mid-morning. Chances of IFR ceilings are less than 20%.

PRELIMINARY POINT TEMPS/POPS

Oklahoma City OK 65 84 67 82 / 10 20 20 40 Hobart OK 62 90 64 87 / 20 20 20 30 Wichita Falls TX 67 89 67 84 / 20 20 20 30 Gage OK 57 89 59 87 / 10 0 0 10 Ponca City OK 64 85 67 85 / 10 20 20 30 Durant OK 67 82 67 80 / 10 10 20 30

OUN WATCHES/WARNINGS/ADVISORIES

OK...Fire Weather Watch from Monday afternoon through Monday evening for OKZ004-005-009-010.

TX...None.