textproduct: Topeka

KEY MESSAGES

- Isolated showers and storms are possible (10-20%) over east central KS this evening. There is a marginal risk for severe weather.

- There is a 15-30% chance of showers and storms Thursday morning and again Thursday evening.

- Hot and humid weather is forecast Friday through Sunday giving a taste of summer before a cold front moves through Monday. Scattered showers and storms will be possible Saturday through Monday.

DISCUSSION

Issued at 223 PM CDT Tue May 12 2026

19Z water vapor imagery showed a shortwave moving through the Upper Midwest into the Great Lakes with upper ridging over the western US. A closed upper low was off the coast of the Pacific Northwest. Surface obs placed low pressure across northern WI with a trailing frontal boundary stretching through IA and into north central KS.

The frontal boundary is forecast to continue sliding south late this afternoon and into the evening with CAMs showing some isolated convection forming over Coffey, Anderson and Franklin counties around 00Z. Instability is progged to be limited to around 1000 J/kg in the vicinity of the boundary with effective bulk shear remaining relatively weak. So chances for severe weather appear to be low, but not zero either. The boundary layer begins to stabilize shortly after sunset and the chances for precip diminish towards 03Z. For the rest of the night and through Wednesday, surface ridging and dry air are likely to bring cool temps in the morning. Sunny skies on Wednesday are forecast to help highs warm to around 80 degrees.

There is a signal from the models for good moisture and theta-e advection on the nose of the low level jet Wednesday night and Thursday morning. Curiously the GFS which has been developing some QPF also has some mid level capping above the lift of the low level jet. Nevertheless the 12Z NAM also has a similar signal with deep isentropic upglide and is developing some QPF. Steepening mid level lapse rates are forecast from the models and based on forecast soundings, effective shear looks to also be strengthening. This may allow from some elevated severe storms during the early morning hours of Thursday. The NBM came in dry due to the lack of QPF from many of the models. But think there is a strong enough signal that at least a slight chance POP is needed. Later on Thursday a shortwave is progged to move over the forecast area bringing another chance for showers and storms. Forecast soundings show a little bit more inhibition by Thursday evening in the form of an elevated mixed layer. So there is some question as to coverage of showers and whether they would be tapped into the boundary layer moisture and instability.

There is a good consensus among the operational and ensemble solutions through Saturday with increasing spread in solutions for the last few days of the forecast. The overall pattern is expected to have an upper trough develop over the Great Basin this weekend with prolonged southerly low level flow helping temps to warm up and bring gulf moisture into the region. A weak boundary in the area may act as a focus for precip through the weekend and with the dewpoints forecast to be in the upper 50s to near 70, it is hard to rule out chances for showers and storms. So have stuck with the NBM and chance POPs through the weekend. Better chances for precip may be on Monday as 12Z operational solutions want to bring a better defined cold front through the state as shortwave energy lifts through the central and northern plains. Temperatures are forecast to be well above normal, especially from Friday through Sunday with highs expected to be in the lower and middle 90s.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1143 AM CDT Tue May 12 2026

VFR conditions should persist thanks to dry air ahead of a weak FROPA expected around 00Z. CAMs hold off on any convective initiation until the boundary is south of the terminals, so will keep a dry forecast going.

CLIMATE

Issued at 223 PM CDT Tue May 12 2026

Record High Temperature for May 15

Record (Year) Forecast Topeka 95 (1944) 93 Concordia 91 (1944, 2012) 92

Record Highest Minimum Temperature for May 15

Record (Year) Forecast Topeka 71 (1977) 66 Concordia 69 (1962) 62

Record High Temperature for May 16

Record (Year) Forecast Topeka 95 (1931) 91 Concordia 93 (2019) 91

TOP WATCHES/WARNINGS/ADVISORIES

None.