Ottawa, Kansas 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

567
FXUS63 KTOP 200549
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1249 AM CDT Thu Aug 20 2026

.KEY MESSAGES...

- Thunderstorms currently moving south across Nebraska may produce
  damaging winds and large hail across far northern KS before
  weakening as they move farther south towards Interstate 70.

- There are additional chances for showers and storms Friday into
the weekend, but low predictability of timing and location leads to
low confidence.

- Temperatures stay near average through early next week.

&&

.DISCUSSION...
Issued at 128 PM CDT Wed Aug 19 2026

The current short term focus is on a complex of severe thunderstorms
moving southeast across eastern Nebraska. Morning showers and
lingering clouds have limited instability across northeast Kansas,
so we should see a weakening trend as the complex continues south.
The question is how fast will these storms weaken? Recent CAM
guidance weakens them below severe criteria before they move into
Kansas, but given the current organization of the line it seems
plausible some low-end severe risk will persist into Kansas. This
would mainly be 330-700 PM across the northern tier or two of
counties, where clearing skies have allowed 2000-3000 J/kg of ML
CAPE to develop. By the time storms near the I-70 corridor towards
sunset, more confident they will be fizzling out, given increasing
CIN with southern extent and nocturnal destabilization.

Surface ridging builds in overnight, resulting in calm and mostly
clear conditions. With lingering surface moisture, expecting some
patchy fog to develop, particularly in the favored river valley
locations. Thursday should remain dry as surface ridging remains in
place, though can`t rule out a few overnight showers and storms
towards central KS with the remnants of earlier storms farther
northwest. Some patchy shallow fog appears likely again Thursday
night across eastern KS, where calm and mostly clear conditions
should persist.

Friday into the weekend and early next week, the region will remain
under northwest flow aloft as upper ridging strengthens to our west.
With several weak shortwaves moving through this flow, we should see
another chance or two at scattered showers and storms. The first and
best of these chances looks to arrive Friday and Friday night. Exact
timing and coverage remains uncertain, as upstream convection
Thursday night into Friday morning should have a big impact on where
any storms develop Friday PM. But an unstable and seasonably sheared
environment will be in place across much of the area, especially NW
towards north-central KS. So will have to watch for a few stronger
storms, conditionally. Temperatures throughout the first half of
next week will also be tied to clouds and precipitation, but overall
look to stay near average values.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1242 AM CDT Thu Aug 20 2026

Main challenge this period will be fog through the early morning
hours. Terminals are on the southwest edge of the most favorable zone
for fog, and think this setup leans more towards patchy shallow fog
as opposed to deeper, more widespread fog. Forecast soundings show
some elevated winds off the surface that would point towards shallow
fog as well. Potential is there for some brief drops to IFR or even
LIFR vis at times though, so haven`t made changes to vis in tempo
groups or timing. Once fog mixes out, it should lift to stratus
briefly before clearing completely. VFR with light winds otherwise.

&&

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

&&

$$

DISCUSSION...Reese
AVIATION...Picha