textproduct: Topeka

KEY MESSAGES

- A cold front is expected to move through Today shifting winds to the north and bringing cooler weather to the region.

- Showers and thunderstorms are likely (50-90%) Wednesday through Wednesday night. A few strong to severe storms are possible on Wednesday. There could be some localized heavy rainfall. - Another round of showers and thunderstorms is forecast Friday and into Saturday morning.

DISCUSSION

Issued at 343 AM CDT Tue Mar 31 2026

Early this morning, water vapor satellite imagery showed an upper trough across the northern Plains. An amplified upper level trough was located across the Gulf of Alaska. A positive tilt H5 trough was located across the eastern Pacific off the CA coast.

The 7Z surface map showed a surface low along the central IA/MN border, with a cold front extending west-southwest across east central NE, then southwest across NE into southwest NE, and southeast WY. Gusty southerly winds were noted across the CWA. Temperatures were in the lower to mid 70s. There was a 50-60KT LLJ across the eastern half of the CWA. The LLJ was causing weak isentropic lift and a few isolated showers have developed. I will put a 10 to 14 pops across east central KS for these isolated showers or if more isolated showers develop during the morning hours.

Today and Tonight:

The front across NE will shift southeast across the CWA after 12Z and through the mid afternoon hours. Those areas southeast of the front will see highs in the lower to mid 80s early this afternoon before FROPA. I have Topeka at 83 degrees just ahead of the front at 1 PM. While the western and central counties of the CWA will be in the upper 60s to lower 70s, After the FROPA, temperatures will slowly fall into 70s across east central KS.

Most CAMs do not show showers or storms developing along the front, until the front is southeast of the CWA by 22Z. The 12Z NAM and NSSL ARW have some spotty showers developing north of the front across the southeast counties of the CWA. The GFS model develops convection across the southeast counties ahead and behind the front, and is probably the reason why the NBM has higher POPs across the areas along and southeast of I-35, and even up to I-70 from Topeka and points east. I'm leaning more to the CAM solutions and even the ECMWF is more in line with the CAMs.

Tonight, the H5 trough off the CA coast will move onshore and shift east into the southwestern US. The stronger mid level southwesterly flow across the Rockies will cause a lee surface low to develop across the south Plains of TX. The 850mb winds will back more to the south through the night and advect richer Gulf moisture northward across the Plains Wednesday morning. The CAMs continue to show only isolated showers developing in response to weak isentropic lift. The GFS shows stronger isentropic lift developing, and expands the showers and elevated thunderstorms across the southeast counties, northwest across much of east central KS. The ECMWF shows the more enhanced isentropic lift east to the CWA across MO but builds the elevated convection westward into east central KS after 12Z. There may be enough MUCAPE 800-1200 J/KG for some of the isolated elevated thunderstorms to produce quarter size hail into Wednesday morning.

Wednesday through Wednesday night:

The H5 trough across the southwest US will shift east across the central and southern Plains Wednesday night. The 6Z HRRR forecast convection developing Wednesday afternoon and continuing into the evening hours ahead of a surface low that will deepen across western KS. The surface front across northern OK late Tonight will lift northward as a warm front into the northern counties of the CWA by Wednesday afternoon. The ECMWF has the warm front lifting into southern NE by 00Z.

The 6Z HRRR forecast soundings show MLCAPE of 1000 to 1500 J/KG and some curvature in the low-level hodograph. If discrete storms do form in the afternoon hours across the CWA, there may be enough low-level vertical windshear for supercell thunderstorms. But these discrete storms will form into line segments through the afternoon, which may still have some embedded rotating updrafts. The primary threat from discrete storms and line segments will be large hail and damaging wind gusts, and I cannot rule out a weak tornado or two with any discrete supercell thunderstorm. Most CAMS along with the GFS and NAM12 show the best instability along and east of a Council Grove to Holton line during the afternoon and evening hours.

After 00Z most CAMs show the line segment of storms congealing into a line of storms due to surface convergence ahead of the Pacific front, and ascent ahead of the H5 trough. The primary threat from a line of storms into the evening hours across east central will be isolated damaging wind gusts. As the H5 trough tracks across the Plains the surface low will track northeast into southwest IA and the trailing Pacific front should move east of the CWA during the early morning hours of Thursday bringing an end to the showers and storms.

Thursday through Thursday night:

An H5 trough will move onshore across the Pacific northwest, then dig southeast into the central Rockies by 12Z Friday. Highs Thursday will be closer to seasonal normals with lower 60s north and mid 60s to around 70 degrees central and south.

Friday through Saturday:

The extended models are in good agreement, that the H5 trough across the central Rockies will lift northeast into the upper Midwest by 12Z Friday. The richer Gulf moisture will try to return before a cold front shifts southeast across the CWA. The best chance for showers and thunderstorms may be during the afternoon and evening hours along and west of the front across east central KS. The central and western counties may not see much rainfall Friday into Friday night. High temperatures will warm into the 70s ahead of the front.

The shower should move out of the CWA Saturday morning. Saturday look cooler as a broad surface ridge of high pressure build southeast across KS. Highs will only reach the lower 50s north, with mid to upper 50s across the remainder of the CWA.

The LREF total QPF spread from the 25th percentile to the 75th percentile. Starting from late Tuesday night through Saturday morning shows eastern portions of the CWA receiving 1.75" to 2.7", the central counties of the CWA receiving 0.8" to 1.8", and the western counties of the CWA receiving the least amount of rain from 0.25" to 1.25"

Sunday through Tuesday:

The upper flow will become northwesterly. Expect dry conditons with highs in the mid 50s to lower 60s on Sunday, and lower to upper 60s Monday and Tuesday

AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/

Issued at 636 AM CDT Tue Mar 31 2026

The southwesterly low-level jet has decreased down to 45 KTS at 2000 feet across KTOP and KFOE but KFOE winds are 15KTS Gust to 23KTS, so I took out the low-level shear at KFOE. KTWX VAD is now below 40 KTS at 2000 feet, so I took the low level wind shear out at KMHK. The winds will veer more to the southwest and west at 13KTS with gusts to 22KTS before the front moves through. Once the front passes in the late morning and early afternoon hours, winds will be north-northwest at 12 to 15 KTS with gusts of 20 to 25 KTS into the evening hours. MVFR ceilings will develop after 8Z, along with a widely scattered showers. The thunderstorms should stay southeast of the terminals Tonight.

TOP WATCHES/WARNINGS/ADVISORIES

None.