710
FXUS63 KTOP 171031
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
531 AM CDT Sat May 17 2025

.KEY MESSAGES...

- Severe weather potential increases during the afternoon and
evening hours Sunday. Large hail and heavy rain will be the main
threats, with some tornado potential particularly in far
southern/western portions of the area.

- Another round of severe weather potential comes Monday afternoon
and evening. Large hail and damaging winds the main threat, though a
few tornadoes will also be possible.

- Cooler and quieter stretch of weather arrives Tuesday.

&&

.DISCUSSION...
Issued at 243 AM CDT Sat May 17 2025

A progressive upper pattern remains in place across the country this
morning. The powerful upper low responsible for yesterday`s severe
weather across the Ohio Valley is centered over Wisconsin, while
another strong trough begins to dig southeast over the West Coast.
Ridging between the two troughs is currently keeping our area mild,
dry, and quiet, as dewpoints remain in the 30s/40s. However this
will change for the second half of the weekend as the West Coast
trough quickly ejects eastward towards the Plains.

With the approach of the western trough, moisture will quickly
advect northward, and we should see a few elevated showers and
thunderstorms as early as Saturday night. As we turn our attention
to Sunday, there remain a lot of questions. And most of these
questions are tied to the northward movement of the warm front, as
guidance remains inconsistent in its placement by Sunday afternoon.
I suspect a lot of this inconsistency is tied to the amount of
clouds and convection that develop north of the front during the
first half of the day. Widespread showers and storms often tend to
hinder northward advancement in setups like this, and I do tend to
lean slightly towards this scenario. This would also keep the main
severe weather threat as large hail with elevated storms north of
the front. However, if fewer clouds and precipitation develops north
of the warm front, this could help it mix northward faster. This
would also lead to more sunshine and heating along the boundary that
would increase the potential for surface based storms to develop.
Given backed surface winds and strong shear along the front, this
scenario would be more concerning for tornado potential. The current
forecast roughly splits the difference between these two scenarios.
Large hail is kept as the main threat for most of the area, with the
best chance for a tornado confined to far western/southern portions
of the area along the most likely warm front position. Do think
we`ll be able to narrow in on this uncertainty throughout the day
today as more high-res guidance comes in. Additional storms may
develop farther west along the western/central KS dryline, however
confidence is high that this separate area of development will stay
well to our west.

By Monday, the main upper trough will shift eastward, allowing a
deep surface low and the dryline to move closer to eastern Kansas. A
few models hint at convection developing late Monday morning across
Oklahoma and moving northeast across southeast Kansas. This seems
like an unlikely scenario, but could push some cloud cover across
eastern Kansas if it occurred. Assuming this fly-in-the-ointment
scenario doesn`t pan out though, ample heating east of the dryline
would allow for around 3000 J/kg of ML CAPE to develop. Coupled with
40-50 kts of mostly boundary parallel shear, this would be favorable
for initial supercells with a very large hail and damaging wind
threat. Low-level shear doesn`t look all that high through early
evening, but may increase enough by mid-evening that the tornado
potential briefly increases with any still discrete supercell across
east-central KS. Similar to Sunday, there remain some uncertainties
that we hope to better resolve as we approach the event, so stay
tuned.

By Tuesday, there`s good agreement in guidance that the upper trough
axis will have passed to our east, pushing a cold front through
eastern KS. This will keep the rest of the week drier and much
cooler. Highs look to stay in the 70s Tuesday through Friday, with
Wednesday likely sticking in the 60s amidst steady northerly
winds.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 529 AM CDT Sat May 17 2025

VFR conditions continue this period with just a few high clouds
in place. Northwest winds around or below 10 kts early this
morning gradually become more northeasterly by later this
afternoon into the evening.

&&

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

&&

$$

DISCUSSION...Reese
AVIATION...Reese