Ottawa, Kansas 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

633
FXUS63 KTOP 201620
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1120 AM CDT Sun Jul 20 2025

.KEY MESSAGES...

- A prolonged period of hot weather is expected into next
  weekend and beyond.

- Showers and storms could move into parts of northern KS
  overnight tonight into early Monday morning.

- There is low confidence in severe storms, but a marginal risk
  for severe wind gusts remains.

&&

.UPDATE...
Issued at 1120 AM CDT Sun Jul 20 2025

A weak inverted surface trough has setup across northeast KS
with perhaps some weak vorticity advection within the westerly
mid level flow aloft have allowed scattered showers to persist
through the morning. The 14Z RAP shows weak isentropic lift
along the inverted trough continuing through the afternoon, so
have updated the forecast to keep some scattered precip wording
in the forecast through the day.

The increased cloud cover may act to keep highs a few degrees
cooler. Although short term guidance still wants to warm temps
up into the middle 90s. If the sun brakes out later, temps could
easily shoot up with the light showers only reinforcing the
boundary layer moisture. So do not plan to make any changes to
the heat warning.

&&

.DISCUSSION...
Issued at 323 AM CDT Sun Jul 20 2025

Early this morning water vapor satellite showed a mid-level
perturbation/MCV moving east across northern KS/southern NE. A move
amplified upper trough has moved onshore across the Pacific
Northwest. An amplified upper trough was moving east across northern
New England. A broad upper ridge extended from the southeast US,
westward across the southern Plains into NM.

At the surface the thunderstorms across central NE and west central
KS have caused an outflow boundary to push southeast across most of
the CWA. at 230 AM the outflow boundary (OFB) extended from MCI,
southwest to EMP, along I-35. A few showers continued north of the
boundary across the CWA. A stationary front was located along
and just south of I-80 from IA across NE.

Today and Tonight:

The OFB will probably push just into the southeast counties of
the CWA and become stationary and most likely will washout
during the mid morning hours. The mid level clouds should
scatter out and afternoon insolation combined with southerly
winds will help highs to reach the lower to mid 90s along the NE
border with mid to upper 90s across the southern half of the
CWA. Surface dewpoints will probably remain in the lower 70s
along and south of I-70 causing heat indices of 104 to 108
degrees. Therefore, the excessive heat warning remains in effect
Today and Tonight. Thunderstorms will develop along the
stationary boundary across central and western NE. These storms
may build southeast into the northern counties of the CWA late
Tonight. If the storms do not totally weaken, then there may be
some gusty winds with any complex of storms with 50 to 60 MPH
winds possible.

Monday through Wednesday night:

The H5 trough across the Pacific northwest will shear apart with the
more amplified northern section moving east across the northern
Plains and southern Canada. the southern stream trough will remain
cut off along the central and southern CA coast. The H5 ridge across
the southern Plains will amplify northward across the central Plains
and Mid MS River valley. Look for high temperatures to remain in the
mid to upper 90s with some 100 degree readings possible. Surface
dewpoints will only mix down to around 70 degrees in the eastern
counties of the CWA. Deeper mixing of the PBL, may mix out afternoon
dewpoints into the mid 60s across much of the western half of the
CWA. However, afternoon heat indices will continue to reach the 104
to 109 degree range sough of a Holton to Concordia line. Overnight
lows will only drop off into the mid 70s.

Thursday through Friday night:

The GFS and ECMWF show a series of southern stream mid level
perturbation breaking down the H5 ridge a bit across the central
Plains. The more amplified H5 ridge axis will shift east across the
east central US. Ascent ahead of any mid-level perturbation may
cause enough cloud cover and thunderstorm chances in the afternoon
hours to reduce the Heat indices down to 100-105 degree range.
However, if these mid-level perturbations are weaker, we may not see
much cloud cover and very low precip chances, if any. Then the
heat advisory may need to be extended into Thursday.

Thursday night into Friday a weak front will push south of the CWA
giving a slight bit of relief from the heat but heat indices may
still reach into the 100-104 degree range along and south of I-70
Friday afternoon.

Saturday through Sunday:

The extreme heat may return as the ECMWF and Canadian models
forecast the ridge axis to amplify across the central Plains, with
the center of the H5 ridge axis across southwest KS to the northern
TX PNHDL. The GFS is a bit farther west with the center of the ridge
axis. High temperatures will warm back into the mid to upper
90s on Saturday, with some readings around 100 degrees on
Sunday. Afternoon heat indices may once again climb above 105
degrees.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1120 AM CDT Sun Jul 20 2025

Scattered shower activity with perhaps some lightning is
expected to linger through the afternoon. Outside of a brief
shower with some temporary MVFR visibilities, VFR conditions
should prevail with mainly broken mid level clouds. Will try to
keep from broad brushing precip chances in the forecast with a
targeted TEMPO group. But there is a 20 to 40 percent chance the
elevated showers and storms persist through the night and into
Monday morning.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Watch from Monday afternoon through Wednesday
evening for KSZ008-KSZ009-KSZ010-KSZ011-KSZ012-KSZ020-KSZ024.

Extreme Heat Warning until 7 PM CDT Wednesday for KSZ021-
KSZ022-KSZ023-KSZ026-KSZ034-KSZ035-KSZ036-KSZ037-KSZ038-KSZ039-
KSZ040-KSZ054-KSZ055-KSZ056-KSZ058-KSZ059.

&&

$$

UPDATE...Wolters
DISCUSSION...Gargan
AVIATION...Wolters