textproduct: Topeka

KEY MESSAGES

- Confidence is increasing in severe storms moving across the area this evening, with the highest threat towards north central KS. Damaging wind is the main hazard, along with large hail and a tornado or two.

- Heavy rainfall with localized flooding is also possible, so a Flood Watch has been issued for this evening and overnight.

- Hot and humid conditions take shape Tuesday. Heat Advisory has been expanded area-wide.

- Additional storm chances come later this week, particularly Wednesday, followed by cooler temperatures to end the week.

DISCUSSION

Issued at 316 PM CDT Mon Jun 8 2026

Large-scale pattern via water vapor imagery shows broad troughing across the western CONUS with one shortwave now moving well north into Canada and another shortwave trough axis off the Pacific coast. Surface low pressure is located near the TX/OK panhandles and southwest KS, with a warm front extending out of that across our area north of the I-70 corridor. An outflow boundary is noted via visible satellite near the KS/NE border into south central NE. Ahead of these boundaries, a very moist and unstable air mass is in place across our area with 4000-5000 J/kg of CAPE and dew points in the low/mid 70s.

By early this evening, there looks to be just enough sfc convergence near the center of the low towards central KS as well as in the aforementioned area along the KS/NE border. This would initially allow for a few discrete supercells to develop before they congeal into a line later this evening. As mentioned earlier, we have plenty of instability, and deep-layer shear of 35-40 kts would support a damaging wind and large hail threat. Additionally, backed sfc winds result in veering low-level winds with 0-3km shear around 30 kts, so there is a reasonable tornado risk with initial discrete cells as well. CAMs this morning have been consistent in these cells evolving into an MCS, resulting in damaging wind becoming the primary severe weather threat with time. If storms are progressive enough in nature, flooding could be less of an issue, but if they turn into more of an east-west oriented line with training (as indicated in some of the morning CAM guidance as well), this would present a bigger flooding threat. In any case, Pwat looks to approach or exceed 2 inches, which is even higher than it has been in recent days. HREF mean has a swath of QPF amounts between 1-1.5", which seems like a reasonable average for most locations. However, 90th percentile has a swath of 2-4" along the I-70 corridor with individual HREF members showing isolated pockets of locally higher amounts than that. The HREF also has a signal for rainfall rates at least an inch per hour along and south of I-70 this evening. With this in mind along, decided to go ahead with a Flood Watch given that much of the CWA is sensitive to high rainfall rates with the recent heavy rain in the area.

Storms should move out of the area before sunrise Tuesday, leaving a hot and muggy air mass in place for the day. Portions of the area are more on the marginal side for a Heat Advisory, but considering this is the first one of the year, decided to expand the advisory to include the entire area with most places likely reaching heat indices around 105, even if only a few degrees short.

Most rain west of the area looks to dissipate before it reaches much of our area, with the exception of perhaps our far western counties in the evening. The next best chance for storms comes Wednesday afternoon and evening with an approaching cold front, which could present another risk for severe storms. That front pushes east into Thursday, with lower storm chances lingering in far eastern KS that afternoon. Wednesday may bring another day of heat indices around 105 degrees for portions of the area, but this looks to be less widespread compared to Tuesday. From there, temperatures cool down later in the week behind the cold front with highs in the 80s and lows in the 60s from Thursday onward.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1233 PM CDT Mon Jun 8 2026

Guidance from 12Z CAMs has been consistent on maintaining a cluster of storms moving in from northwest and north central KS this evening. Have gone with a 3-hour window for TS as a best first guess, although timing adjustments may be needed. Otherwise, expect MVFR cigs this afternoon to eventually lift to VFR later this afternoon. South winds pick up above 10 kts toward the end of the period.

TOP WATCHES/WARNINGS/ADVISORIES

Heat Advisory from noon to 9 PM CDT Tuesday for KSZ008-KSZ009- KSZ010-KSZ011-KSZ012-KSZ020-KSZ021-KSZ022-KSZ023-KSZ024-KSZ026- KSZ034-KSZ035-KSZ036-KSZ037-KSZ038-KSZ039-KSZ040-KSZ054-KSZ055- KSZ056-KSZ058-KSZ059. Flood Watch from 7 PM CDT this evening through Tuesday morning for KSZ020-KSZ021-KSZ022-KSZ023-KSZ024-KSZ026-KSZ034-KSZ035-KSZ036- KSZ037-KSZ038-KSZ039-KSZ040-KSZ054-KSZ055-KSZ056-KSZ058-KSZ059.