Severe Thunderstorm Warning 200, NWS Topeka, KS

Area Forecast Discussion
National Weather Service Topeka KS
1223 PM CDT Mon May 18 2026

.KEY MESSAGES...

- Numerous severe storms are expected late this afternoon over
  north central Kansas, spreading across northeast Kansas this
  evening and overnight. Threats include very large hail (2-4+
  inches in diameter), Damaging wind gusts to 80 mph, flash
  flooding, and tornadoes (a few strong).

- A Flood Watch is in effect for all of northeast and north
  central Kansas where antecedent heavy rainfall has enhanced
  the threat for flash flooding this evening.

- After cooler and dry conditions Tue. and Wed., storm chances
  return with the highest being on Thursday. Widespread severe
  probabilities are low at this time.

&&

.DISCUSSION...
Issued at 232 AM CDT Mon May 18 2026

Active early Monday morning as a decaying line of slow moving
thunderstorms impacts portions of northeast and east central Kansas.
Overall threat has shifted to heavy rainfall as hourly rainfall
rates of 1 to 2 inches have been observed. Totals have currently
ranged from 1 to 5 inches with the highest amounts focused over
north central Kansas. As the low level jet wanes, activity is
anticipated to dissipate by mid morning, leaving the stratus in
place and potentially an outflow boundary in far eastern Kansas to
MO. How quickly the atmosphere recovers in eastern Kansas is
uncertain, potentially generating scattered severe storms by mid
afternoon. Confidence in this scenario is somewhat bolstered by the
last few runs of the HRRR/RAP, forming convection south of I-70 and
east of I-35. Forecast soundings in vicinity of this outflow
boundary exhibit strong low and mid level wind shear and elevated
CAPE up to around 3000 J/KG. If this occurs, damaging wind gusts,
large hail, and a few tornadoes cannot be ruled out earlier in the
afternoon. Overall confidence for the above scenario is low-medium,
owning to timing and location inconsistencies of current convection
and where the boundary settles by midday.

In terms of the main severe weather setup, no major changes were
noted in forecast trends as the moderate severe risk from SPC
remains centered from the Flint Hills region to the Kansas/Nebraska
border. Negatively tilted upper trough axis across the Four Corners
Region is anticipated to eject into the western high plains between
21Z-00Z. At this time, dryline/cold front is oriented southwest to
northeast over north central Kansas as rich low level moisture
raises dewpoints into the low 70s pooling just ahead of the stalled
boundary. In addition clouds are anticipated to scatter out by late
afternoon, resulting in SFC CAPE exceeding 5000 J/KG amid minimal
inhibition. Strong convergence along the front is sufficient for
discreet convection to form in the 3-5 PM timeframe over north
central Kansas. Initial severe storms will be most intense in terms
of very large hail (2-4+ inches diameter) and strong tornadoes,
especially as the low level jet strengthens in the early evening.
The strong tornado threat persists into the early evening with any
discrete supercells.

Bulk shear vectors parallel to the front suggest discrete cells
transition to a line of storms around 7 PM. Main hazards with the
squall line are damaging wind gusts to 80 mph , brief tornadoes
along the leading edge, and large hail as they quickly translate
east southeast through eastern Kansas. Forward propagating corfidi
vectors are weak (20 kts) while PWAT values increase above 1.5
inches and low/mid level moisture saturates the column. Given the
several inches of rainfall that occurred the last evening, decided
to expand the Flood Watch to cover the entire forecast area through
Tuesday morning. Estimated rainfall totals tonight range from 2 to 5
inches, increasing the likelihood for localized flash flooding.
Activity exits into Missouri between 3 and 6 AM Tuesday.

Much cooler airmass settles in behind the front Tuesday and
Wednesday afternoons as highs only peak in the middle to upper 60s.
Showers and isolated storm chances return by Thursday as broad upper
troughing amplifies to the north and west. However, given the
influence from sfc ridge to the northeast and lack of good return
moisture, the overall severe threat is low. Better dynamics return
by Friday evening, signaling the possibility for strong storms in
the Kansas region.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1223 PM CDT Mon May 18 2026

Confidence is increasing in thunderstorm potential in the 23Z-04Z
window and went ahead with TEMPO inclusion. MVFR cloud should
diminish soon but be more consistent after FROPA around 06Z with some
chance for improvement late in the forecast.

&&

.CLIMATE...
Issued at 234 AM CDT Mon May 18 2026

Record High Temperature

Monday May 18
                 Record (Year)           Forecast
Topeka           94 (1975)               87
Concordia        94 (1967, 1988)         84

Record Warm Low Temperature

Monday May 18
                 Record (Year)           Forecast
Topeka           71 (1911)               68
Concordia        72 (1911)               61

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Tuesday morning for KSZ008-KSZ009-KSZ010-KSZ011-
KSZ012-KSZ020-KSZ021-KSZ022-KSZ023-KSZ024-KSZ026-KSZ034-KSZ035-
KSZ036-KSZ037-KSZ038-KSZ039-KSZ040-KSZ054-KSZ055-KSZ056-KSZ058-
KSZ059.
Wind Advisory until 9 PM CDT this evening for KSZ035-KSZ036-KSZ037-
KSZ038-KSZ054.

&&

DISCUSSION...Prieto
AVIATION...Poage
CLIMATE...Griesemer

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