458
FXUS63 KTOP 220510
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1210 AM CDT Wed May 22 2024

.KEY MESSAGES...

- Next round of thunderstorms is expected Thursday night and
  Friday morning. There is a risk some of these could be severe.

- Seasonal spring weather is forecast for the weekend with
  occasional chances for showers and storms and mild temps.

&&

.DISCUSSION...
Issued at 234 PM CDT Tue May 21 2024

19Z water vapor imagery shows a shortwave trough lifting
northeast through eastern NEB. Radar and surface obs show a
frontal boundary pushing through northeast KS and extending
through southeast KS. 18Z TOP RAOB showed the slightest bit of
MLCIN still ahead of the front.

CAMs have been consistent in showing convection developing and
quickly moving east this afternoon and nothing that we can observe
suggests anything different. So think thunderstorms will be east of
the forecast area by 4 pm or so. SSW low level winds and an
effective straight line hodograph suggests storms may have to mature
some before a tornado risk is realized, likely east of the area. But
copious amounts of CAPE (3500 J/kg MUCAPE) would support rapid
development and a very large hail and damaging wind risk before
storms move east.

Tonight models show a weak shortwave passing overhead late in the
period and Wednesday morning. Instability will be greatly limited by
dry air behind the front but there could be enough vertical motion
for some elevated showers through the morning hours. Not sure how
widespread it may be with much of the QPF progs only showing a
hundredth or two if any precip at all, so have kept POPs around 20
percent.

After Wednesday morning, the next chance for showers and
thunderstorms looks to come late Thursday and into Friday morning as
southerly low level winds advect moisture back north and another
frontal system moves in from the northwest. Models show bulk sheer
to be rather weak in the 20KT to 40KT range ahead of the boundary,
but CAPE could be sufficient for some intense updrafts. Forecast
hodographs are a little concerning ahead of the boundary but
soundings suggest storms would be elevated. So will need to keep an
eye on the potential for a nocturnal tornado risk as models forecast
0-1 SRH of 200-400 m2/s2.

There is the potential for a couple low amplitude shortwaves passing
through a quasi zonal pattern Saturday night and again Monday. So
have kept the chance POPs that the NBM has. The GFS and ECMWF show
occasional boundaries making into KS through the extended. This
should keep temps a little more seasonable with highs in the 70s to
around 80 and lows in the 50s.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1210 AM CDT Wed May 22 2024

VFR conditions prevail. High-based showers could impact terminals
between 09-13z, but are expected to dissipate as they do so.
Have input VCSH at KMHK where chances for showers are higher.
Winds remain light from the west today, becoming south-southeasterly
after 00z.

&&

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

&&

$$

DISCUSSION...Wolters
AVIATION...Flanagan