Ottawa, Kansas 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

996
FXUS63 KTOP 191130
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
630 AM CDT Sat Jul 19 2025

.KEY MESSAGES...

- We will be entering prolonged period of hot weather for the
  region.

- An Extreme Heat Warning goes into effect for parts of the area
  Today, with a Watch for the remained of the area beginning
  Monday. The warning and watch will go through Wednesday but
  may need to be expanded through Thursday.

- Isolated to widely scattered showers and storms are expected
  this morning. May be again this afternoon and Tonight. Next
  week looks dry with little chance for meaningful rain.

&&

.DISCUSSION...
Issued at 255 AM CDT Sat Jul 19 2025

Early this morning a broad upper level ridge extended from NM east
across the southern Plains, then east into the southeast US. The main
H5 jet was located across the northern US. Several embedded
shortwaves extended from the Pacific northwest, east across
southern Canada and the northern Plains into New England. A filling
southern stream upper low was moving onshore across southern
CA. A weak southern stream H5 jet of only 20 KTS was rounding
the ride axis and lifting northeast across northern CO, then
east across NE and northern KS and into northern MO.

The 2 AM surface analysis showed a slow moving cold front extending
from a surface low in north central MN, southwest across
eastern SD into western NE and SE WY.


Today through Sunday night:

A southwesterly LLJ of 30 to 35 KTS across central KS was providing
some ascent for showers and a few elevated storms across the western
and central counties of the CWA. These elevated showers and
storms will diminish once the PBL mixes deeper after 13Z.

A complex of storms in northeast NE will probably weaken as they
head southeast into an environment with lower vertical wind shear.
If an outflow boundary remains in tact, through the morning hours,
then a few storms may develop ahead or just behind the OFB across
the northeast counties around sunrise. The OFB may provide some gusty
winds across the northeast counties around 7 AM.

Skies will remain partly to mostly sunny Today and afternoon
sfc heating combined with any weak perturbations may cause a few
thunderstorms to develop. The vertical wind shear looks weak
but MLCAPES of 2000-3000 J/KG may cause a few strong pulse
storms with gusty winds and brief heavy rains.

There may be another complex of storms that will develop across
western NE along a stationary front late this afternoon and evening.
However, as the storm complex moves southeast it will move into
a lower vertical wind shear environment and the outflow will
undercut the surface outflow. Once again thunderstorms may
develop along this OFB as it moves southeast into portions of
the northern CWA providing enough ascent for widely scattered
thunderstorms to develop during the early morning hours of
Sunday.

Once again peak surface heating combined with any weak perturbations
rounding the southern Plains H5 ridge may cause isolated showers and
storms to develop. MLCAPES will be around 2000 J/kg, so some of
the pulse storms may produce stronger outflow winds.

High Temperatures Saturday and Sunday will range from the mid 90s
north to the upper 90s to around 100 degrees across the central and
southern counties of the CWA. The southwestern counties may see
deeper mixing of the PBL, so dewpoints may mix down into the mid
60s. The eastern counties will probably keep lower 70 dewpoints
through the afternoon hours. Heat indices this and Sunday afternoon
will reach the 104 to 108 degree range along and south of the
I-70 corridor. Heat indices across the northern counties will
only reach the 100 to 104 degree range. Therefore, the heat
warning will continue for the southern two-thirds of the CWA.


Monday through Saturday:

It will be a hot week as the southern stream H5 ridge amplifies
northward across the central Plains and mid MS River Valley.
Highs temperatures will reach the upper 90s to around 103
degrees. It looks dry through Thursday as any mid-level
perturbations will lift farther north around the H5 ridge axis.
The PBL may mix deeper, thus afternoon dewpoints may mix back
into the mid to upper 60s. However, most areas will see heat
indices in the 102 to 108 degree range, so the heat warning will
continue and the heat watch may need to be upgraded to a heat
warning through Thursday.

Thursday through Friday night, the H5 ridge may break down a bit as
a southern stream H5 trough fills as it lifts northeast around the
H5 ridge axis. Both the GFS and ECMWF show the low amplitude H5
trough lifting around the H5 ridge axis, which may provide the area
with another low chance for thunderstorms and maybe high
temperatures in the mid to upper 90s on Friday. The ECMWF shows
the H5 ridge amplifying across the central Plains and anchoring
itself over KS. Thus, this heat wave may last through the end of
July.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 626 AM CDT Sat Jul 19 2025

A 35 KT LLJ at 1200 feet may produce low level shear at the
terminals through 14Z SAT. Otherwise, expect VFR conditions. I
cannot rule out an isolated thunderstorm this afternoon through
Tonight. southwest winds 5 to 10 KTS will become more southerly
and increase to 11 to 13 KTS with gusts to 18 to 22 KTS by
afternoon.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Watch from Monday afternoon through Wednesday
evening for KSZ008-KSZ009-KSZ010-KSZ011-KSZ012-KSZ020-KSZ024.
Extreme Heat Warning from noon today to 7 PM CDT Wednesday for
KSZ021-KSZ022-KSZ023-KSZ026-KSZ034-KSZ035-KSZ036-KSZ037-KSZ038-
KSZ039-KSZ040-KSZ054-KSZ055-KSZ056-KSZ058-KSZ059.

&&

$$

DISCUSSION...Gargan
AVIATION...Gargan