339
FXUS63 KTOP 221741
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1241 PM CDT Tue Apr 22 2025

.KEY MESSAGES...

- A few strong to severe storms possible this evening, with wind
and hail the main threats. Greatest chance towards central Kansas.

- Wet pattern continues into Friday. Occasional showers and
  storms capable of producing heavy rain, localized flooding,
  and a lower end severe weather threat.

- Temperatures stay near to slightly above normal, with highs in
  the 70s.

&&

.DISCUSSION...
Issued at 334 AM CDT Tue Apr 22 2025

Water vapor imagery this morning shows generally zonal flow across
the CONUS, with one more prominent embedded shortwave moving across
the northern Plains. A cold front associated with this shortwave is
moving southeast towards our area from southeast Nebraska. Along
with convection over Iowa, a few sprinkles are present along this
front across south-central Nebraska. These may persist into mid-day,
but shouldn`t have much of an effect otherwise. By the evening
hours, the front will stall across northern portions of the forecast
area, stretching from around Brown County west-southwest to a weak
low over central Kansas. Despite weak upper forcing with little
height falls, low-level convergence along the boundary may (60%) be
enough for a few scattered storms to develop 6-8 PM. This
appears most likely closer to the surface low across central
Kansas, where the SPC has added a Slight Risk area (Level 2/5). With
around 30 kts of effective shear, 1500 J/kg of ML CAPE, and
steep mid-level lapse rates, a few storms that develop could be
strong to severe. Hail to around ping pong ball size and 60 mph
gusts would be the main hazards, given a tendency to more of a
multi-cell mode. Assuming storms do develop mid-evening they
should tend to weaken by late evening, though a strengthening
LLJ could keep weaker storms persisting late into the night.

Wednesday into Friday will continue be dominated by broad/weak
southwest flow aloft, more reminiscent of June than late April. As
subtle mid-level perturbations move through this flow, we`ll see
repeated rounds of showers and thunderstorms. Each round will be
somewhat dependent on prior rounds of rain, and where various
surface boundaries and vorticity maxima set up. So confidence in
specific timing and location is quite low throughout the week. Some
minor strong to severe storm threat will persist Wednesday and
perhaps Thursday, but the bigger concern might be repeated rounds of
moderate to heavy rain. Slow-moving storm clusters with PWAT around
the 90th-95th percentile could lead to widespread rainfall of 1-3
inches, along with locally higher amounts where multiple rounds
affect the same area. These higher pockets would be where localized
flooding is most possible. Temperatures each day will also depend on
clouds/rain, but should climb into the 70s on most days.

Rain chances decrease some late Friday into Saturday, before
increasing again late weekend as a stronger upper low begins to
move east towards the Plains. There is still a fair amount of
uncertainty on how this low will evolve as it ejects eastwards,
in both timing and the overall shape of the trough. So
thunderstorm and heavy rain chances will likely increase in some
fashion across the broader Plains region, but it`s too soon to
say if we`ll have any impacts here.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1236 PM CDT Tue Apr 22 2025

The main concern during the 18Z TAFs is whether thunderstorms
will impact airports this evening. Confidence is not overly
high so have gone with a PROB30 group for the period of time
when storms could occur. Otherwise, chances remain below 30
percent. South-southwest winds between 10 and 15 kts decrease
after sunset and remain light into Wednesday morning.


&&

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

&&

$$

DISCUSSION...Reese
AVIATION...Teefey