textproduct: Topeka

KEY MESSAGES

- Red Flag Warning in north-central KS this afternoon and evening. A very high fire danger.

-Storms could impact far eastern KS Tuesday evening, bringing a threat for severe weather.

-Additional storm chances occur Wednesday and again Friday, with more uncertainty on timing/location.

-Cooler weather expected this weekend. Possible freeze and frost early Sunday morning.

DISCUSSION

Issued at 140 PM CDT Mon Apr 13 2026

Early this afternoon, water vapor satellite imagery showed an upper level trough extending from the Great Basin southwest into southern CA. Broad southwesterly mid level flow of 40 to to 50 KTS was noted from the base of the Southwest US trough, extending northeast across the Plains, then northeast across the Upper Midwest and Great Lakes States. A broad upper level ridge was centered off the FL coast across the eastern Gulf.

At the surface, an area of low pressure was located across the northeast NE. A warm front extended east northeast across southern MN. A dryline extended west-southwest across eastern NE, to the far western counties of the CWA, into western OK. Winds ahead of the dryline were south-southwesterly at 15 to 25 MPH and gusts to 40 MPH. West of the dryline, winds veered more to the southwest and dewpoints have dropped down into the mid 30s to lower 40s.

This afternoon and Tonight:

The dryline will move east to a Washington, to Clay center, to Abilene line late this afternoon. Most CAM soundings do not show much of cap but weak confluence along the dryline will not be enough surface convergence to develop thunderstorms. The 3 KM NAM is showing sfc based storms developing across north central OK late this afternoon, which may develop northeastward during the evening hours but most other CAMs do not show any convection developing along the dryline across the CWA. If isolated storms were able to develop ahead of the dryline they would become severe with wind and hail as the primary hazard given MLCAPES around 2000 J/kg and 35 KTS of effective shear. The low level winds may be too veered for a tornado threat. but the probability for storms is below 14 percent across much of the eastern counties of the CWA. But I may place a 15 percent chance in Anderson county in case the 3K NAM is accurate with dryline storms building northeast up towards the southeast counties. Later shifts may need to update this forecast.

Tonight, as the LLJ increases to 40 to 50 KTS across east central KS, I cannot rule out a few elevated storms across portions of east central KS but most of the CAMs do not show storms developing late Tonight into early Tuesday morning.

Tuesday through Wednesday night:

The upper trough across the southwest US will fill as it lifts northeast across the Plains Wednesday night.

Tuesday, the dryline will move east across the central part of the CWA. There will not be as much QG forcing, since the H5 trough will still be farther west across UT/AZ. The surface shows more confluence along the dryline, so most of the area will remain dry. Most CAMs develop surface based storms across northern OK/south central KS and these storms may move northeast along across east central KS. The primary hazards will be large hail and damaging wind gusts but any discrete supercell may spawn a few tornadoes. However, the low-level wind fields looks to be veered, so the chances are much lower.

Wednesday afternoon into Wednesday night will provide a better chance for thunderstorms as the H5 trough shifts east into the Plains. DCVA ahead of the trough axis will provide for stronger ascent. At the surface a cold front will shift southeast into the northern counties and dryline will push east across the southwest counties. Thunderstorms will develop along the front and possibly south along the dryline. Some of these storms may be severe with the primary hazards being large hail and damaging wind gusts. Through the evening hours a line of storms will congeal along the cold front, and the threat will become isolated damaging wind gusts. The front should push southeast of the CWA during the early morning hours of Thursday.

Thursday through Thursday night:

Early Thursday, an upper level trough will move onshore across the Pacific northwest and dig southeast into the Great Basin. We may see a break from any thunderstorms as the Pacific front will push east into western MO. Frontolysis will occur through the afternoon hours and westerly winds will diminish and become southerly through Thursday night.

Friday through Sunday:

The extended range models are in fair agreement. The GFS is a bit more progressive and maybe more favorable for severe thunderstorms during the afternoon and evening hours.The H5 trough across the Great Basin will dig east-southeast across the central Rockies, then across the Plains Friday night into Saturday Morning. A cold front will push southeast across the northern High plains, then southeast across NE through the day. A surface low and dryline across western KS will shift east. Thunderstorms will develop across central KS through the afternoon hour. If discrete thunderstorms develop within the warm sector where there will be sufficient vertical wind shear and instability for supercell thunderstorms. The hazards from supercell thunderstorms would be large hail, damaging wind gusts, and possibly a few tornadoes. It still remains uncertain if these discrete supercells will remain south of the area Friday afternoon. Though the slightly more progressive GFS solution would provide a better chance for supercell thunderstorms developing ahead of the cold front/dryline during the afternoon hours before the storms congeal into a squall line. The slower ECMWF solution shows most storms developing ahead of the cold front during the mid and late evening hours. If a line of storms develop the the primary hazard would be isolated damaging wind gusts along the squall line. The cold front will move southeast of the CWA during the morning hours of Saturday and the rain and thunderstorms will shift east of the area. We will see a cool down by the weekend with highs in the mid 50s north to lower 60s south. Highs Sunday will be in the lower to mid 60s. Low temperatures early Sunday morning may fall below freezing across the northern counties of the CWA with mid 30s across much of the area. Therefore, a freeze warning and frost of advisory may be needed Saturday night into Sunday morning.

An H5 ridge will move towards the Plains next week, which will cause temperatres to warm into the 70s on Monday and the 80s by the middle of next week.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 520 PM CDT Mon Apr 13 2026

VFR at all TAF sites through the TAF period with gusty southerly wind. Some thunderstorms have developed down near Emporia, but confidence in these making it into the Topeka area are too low right now to place any mention in the TAF.

FIRE WEATHER

Issued at 340 AM CDT Mon Apr 13 2026

While green up of vegetation is underway, a Red Flag Warning will continue across north-central KS, where gusty winds and low RH will combine to create extreme fire danger. Dew points are forecast to drop this afternoon in this area as a dryline moves east. Minimum RH behind the dryline could quickly fall to around 20 percent. South-southwest winds will be sustained at 15 to 20 mph with gusts as high as 30 mph throughout the afternoon. Similar conditions will be in place behind the dryline (mainly in central KS) on Tuesday, with minimum RH between 20 and 25 percent and continued gusty south-southwest winds. Fire headlines are not currently anticipated Tuesday. However, at this time the Range Land Fire Index has only a very high fire danger for north central KS. All Burning should be postponed through midweek.

TOP WATCHES/WARNINGS/ADVISORIES

Red Flag Warning until 9 PM CDT this evening for KSZ008-KSZ020- KSZ034.