831
FXUS63 KTOP 231735
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1235 PM CDT Thu May 23 2024

.KEY MESSAGES...

- Severe thunderstorms chances increase this afternoon/evening with
  best chances overnight.

- Additional storms, some severe, Saturday into Saturday night.

- Trending drier Monday-Wednesday of next week with highs in
  the 70s and 80s.

&&

.DISCUSSION...
Issued at 321 AM CDT Thu May 23 2024

Zonal flow exists across the central Plains this morning ahead of a
closed low centered over Idaho. A weak perturbation in the flow has
generated some showers and thunderstorms across central Kansas; this
activity will impact north central Kansas early this morning before
dissipating just after sunrise. Patchy fog has been observed across
east central Kansas where the low-level wind field is weaker. Fog
will burn off quickly after sunrise.

Southerly low-level flow strengthens through the day today, lifting
a warm front north and raising dewpoints into the mid 60s. A dryline
is progged to reside across western/central Kansas by this afternoon
with the warm sector environment featuring 2500-3500 J/kg of surface
based CAPE and 30-40kts of effective shear. A lack of obvious large-
scale ascent leads to lower confidence in storms impacting the area
late this afternoon into the evening as the capping inversion
erodes. There remains a 20-35% chance for storms to develop either
along the dryline or within the broad isentropic ascent. If ascent
is sufficient for convective initiation to occur, the
environment supports severe storms with large hail and damaging
wind gusts being the main hazards. Low-level hodographs depict
curvature of the lowest 1km or so which supports a low end
tornado threat as well. Better ascent arrives overnight as a
closed low ejects across the northern Plains, shunting a cold
front through the area during the overnight hours. Storms that
develop in central Nebraska during the evening are expected to
quickly grow upscale into a line of storms and dive east-
southeast through the late evening and overnight hours.
Uncertainty remains in the intensity of these storms as they
move into the area, especially with southward extent which will
be further removed from the main wave. CAMs show differing
solutions in placement and strength of the QLCS across northeast
Kansas including some that keep the MCS largely north of the
forecast area. Nonetheless, the environment will still be
favorable for severe storms into the overnight period although
increasing CIN supports a weakening trend as the MCS advances
southeast. Damaging wind gusts will be the main hazard with
these storms; further enhancement and veering of the low-level
jet suggest the potential for QLCS mesovortices as well if the
cold pool doesn`t advance ahead of the leading edge of storms.

Showers and storms linger through the morning on Friday before skies
clear for the afternoon with highs in the 70s. Another trough
approaches on Saturday with increasing southerly low-level flow
lifting a warm front back north and a dryline setting up across
western and central Kansas again. The aforementioned wave ejects
across the central Plains during the afternoon and evening leading
to greater large-scale ascent across the area than will be present
today. Even so, uncertainty exists in storm coverage and placement
of the warm front, but the environment south of the front will be
favorable for severe storms. Stay tuned as forecast details will
become clearer as the event approaches. Another cold front moves
through Sunday morning, but showers and some storms may linger
through the day as the upper low is slow to push east. Ensembles
favor an eastern trough, western ridge pattern Monday through
midweek leading to mostly dry conditions and highs in the 70s and
80s.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1231 PM CDT Thu May 23 2024

A cold front will move through the area tonight, bringing a
chance for storms and possible MVFR conditions for a few hours.
This afternoon, VFR prevails with winds increasing slightly
from the south-southeast. A LLJ then strengthens tonight, which
could create some surface gusts near 25 kts. Thunderstorms
become possible near a cold front after 09Z at KMHK and after
10Z at KTOP/KFOE. The front should move through quickly, so only
have TS mentioned for a brief period. Winds will turn to a
northwesterly direction behind the surface boundary Friday
morning.


&&

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

&&

$$

DISCUSSION...Flanagan
AVIATION...Teefey