151
FXUS63 KTOP 180542
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1242 AM CDT Tue Aug 18 2026

.KEY MESSAGES...

- Favorable environment for severe weather tomorrow but still larger
than usual amount of uncertainty for storm timing, coverage, and
location.

- Temperatures stay near to slightly below average for the next week.

- Several additional low chances for showers and storms, particularly
  Wednesday and Friday.

&&

.DISCUSSION...
Issued at 140 PM CDT Mon Aug 17 2026

Broad west-northwesterly flow is present across the region this
afternoon, to the south of a deep upper low up over the Hudson Bay.
At the surface, high pressure is centered over the Missouri River
Valley, keeping quiet conditions in place over eastern KS. Even with
mostly sunny skies, high temperatures are remaining in the 80s, a
welcome change from most of last week. The surface high will depart
east tonight, allowing southerly winds to return in response to a
deepening low over the High Plains. Farther to our northwest,
expecting storms to develop this evening along the surface trough
across portions of South Dakota and Nebraska. These storms will move
southeast into eastern Nebraska by tomorrow morning.

How these storms evolve overnight will play a large role in our
thunderstorm potential Tuesday. Some low potential for gusty winds
could exist with this first round, but the more interesting
potential will be with potential evening storms in their wake. While
shear will be plentiful, increasing to around 40 kts by evening,
thermodynamics will be dependent on the extent of the morning
storms. The more organized and farther west morning storms are, the
farther west outflow will extend. This would limit the potential for
surface-based storms to redevelop, or at least confine the potential
to central KS. On the other hand, if outflow remains weak and better
heating (temps rising into the 90s) can develop across the area,
there would be a window for surface based supercells with large hail
and damaging winds. The former scenario seems a bit more likely at
this time, but will need to consistently monitor the mesoscale setup
over the next 24 hours. There is better confidence in slightly more
elevated storms develop overnight as the main cold front shifts
south. These storms would not have as high of a figurative ceiling
as any earlier surface-based supercells, but could nonetheless
produce some large hail and/or damaging winds.

Cooler temperatures will move in behind the front for Wednesday and
Thursday. Highs should stay in the 80s, perhaps even 70s on
Wednesday if cloud cover can remain persistent. Some lingering
moisture will remain in place behind the cold front, so it`s not out
of the question we see a few additional thunderstorms Wednesday PM.
But the main large scale forcing should stay to our north and west,
so think things will generally stay dry. Uncertainty increases by
the weekend as the upper flow amplifies. Does seem like we should
trend a bit warmer as ridging builds to our west, but with northwest
flow overhead we should stay fairly close to average. Precipitation
chances will remain tied to low-predictability shortwaves moving
through the northwest flow aloft. Slightly better signal for one of
these to pass nearby Friday into Saturday, but confidence is low
this far out.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1237 AM CDT Tue Aug 18 2026

VFR conditions are forecast, but will need to monitor for showers and
thunderstorms mainly towards the end of the period. The convection
currently moving southeastward through Nebraska looks favored to stay
north of terminals as it weakens into northern KS this morning. The
more favorable time frame for storms to impact TAF sites is in the
evening following the passage of a cold front. Timing and location of
these storms is still up in the air though, so have limited mention
to a PROB30 group at all sites for now. Outside of TS, expect light
southerly winds most of the day before they turn to the ENE behind
the front.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Reese
AVIATION...Picha