987
FXUS63 KTOP 190747
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
247 AM CDT Tue Aug 19 2025

.KEY MESSAGES...

- Showers and storms will be possible through the day today and
  into the evening. Confidence in where these storms develop is
  low and could be just about anywhere.

- Some of the storms could be strong enough for an isolated
  damaging wind risk. Isolated heavy rain may be an issue too.

- Dry conditions are forecast for Wednesday through the day
  Friday. A significant cool down is expected by Sunday and
  Monday.

&&

.DISCUSSION...
Issued at 247 AM CDT Tue Aug 19 2025

07Z water vapor placed the center of an upper low over the Four
Corners region as the mean westerlies remained north over the
Canadian plains. Radar reflectivity and profiler data suggested
at least one if not two MCVs had developed over northwest KS.
Surface wind obs suggested a weak boundary with modest
convergence was located across the southern quarter of the
forecast area or ruffly from Ottawa to Council Grove and
Abilene.

The forecast for today and this evening is going to be
characterized by a conditionally unstable atmosphere with weak
flow and forcing. So mesoscale analysis is going to be a big
part of the forecast. Most of the operational solutions want to
keep the weak boundary and subtle convergence over east central
KS through the day. However some solutions advect the MCV more
easterly while others take it more to the south. Based on
current observations, think the better chances for showers and
storms through the day today is along this weak boundary.
However confidence is such that POPs are only in the 20 to 40
percent range as progs are fairly hit or miss on whether storms
develop. Still the environment is progged to be moderately
unstable with surface based CAPE values between 3000 and 4000
J/kg along the boundary. But shear is almost non-existent as
0-6km bulk shear values are only 10 to 15KT. Still the amount of
instability could lead to an isolated damaging wind risk this
afternoon and evening. Heavy rain could also end up being a
problem given the weak winds. Storms may not want to move much.
However they should become outflow dominant with the weak shear
so storms may end up propagating off of the initialization
point. It will be something to keep an eye on.

For Wednesday through Friday, ensembles and operational
solutions show a good signal for dry weather as surface ridging
moves in. There isn`t a lot of cold air advection with this
ridge so temps are expected to only be slightly cooler. But
cooler dewpoint temps should bring some relief from the
humidity. Models show a cold front moving into the area Friday
night as northwest flow aloft develops. There looks to be some
chance for showers and storms with this boundary. The NBM is not
that impressed with the boundary and only has some small POPs
in the 20 to 30 percent range. Will wait to see if models come
into better consensus with the front and precip chances before
upping POPs.

For Saturday through Monday, northwest flow is progged to set
up with shortwave activity moving mainly through the Upper
Midwest. This pattern is expected to bring surface ridging into
the central plains along with cooler temperatures for the
forecast area. The main question is how far southwest the
surface ridge will push, because there is a signal for return
flow from the southern plains into and over the cool high
pressure that could generate precip. Cluster analysis is split
between weaker and deeper shortwave activity through the Upper
Midwest and where the warm air advection pattern sets up. So
have stuck with the blended forecast. 00Z GFS and ECMWF have
trended towards a stronger surface ridge pushing into the
southern high plains, so the forecast may be a little overdone
with POPs Monday morning. But there is still time for the
ensembles to converge on a common solution so have not made any
changes.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1222 AM CDT Tue Aug 19 2025

Latest surface analysis suggests there is a weak area of
convergence across the southern parts of the forecast area with
a weak southwesterly low level jet across northern OK and
southern KS. A moisture axis with dewpoints in the lower to
middle 70s remains across northeast KS. An MCV over northwest
KS is evident from radar and profiler data. Think the main focus
for convection may end up just south and west of the terminals.
where the weak boundary is, but confidence in this is low and
convection is possible just about everywhere. Will opt to amend
if storms become obvious rather than broad brush SH for the
next 18 hrs. Outside if any precip, VFR conditions should
prevail.

&&

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

&&

$$

DISCUSSION...Wolters
AVIATION...Wolters