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000
FXUS63 KTOP 261845
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
145 PM CDT Fri Apr 26 2024

.KEY MESSAGES...

- Several rounds of thunderstorms are forecast through Sunday.

- Severe weather with large hail, damaging winds and even tornadoes
  are possible with the greatest risk on Saturday.

- Additional rounds of heavy rainfall may lead to flooding over east
  central and northeast Kansas.

&&

.DISCUSSION...
Issued at 145 PM CDT Fri Apr 26 2024

An upper low was seen on the 18Z water vapor imagery with a
shortwave trough rotating through the base of the low towards
northeast KS. At the surface, A warm front has lifted mostly
through the forecast area with a dryline extending south through
central KS. Towering CU and a couple thunderstorms have formed
along the dryline.

The question with thunderstorms this evening is the extent to
the south storms form along the dryline. There are mixed results
from the various CAMs with some failing to develop storms as
far south as I-70 and others showing more widespread storms over
northeastern KS. MUCAPE around 3000 J/kg 0-6km shear of 50KT
will be supportive of supercell storms. These storms are
expected to swing to the north and east quickly this evening
which may limit the tornado risk for our area since storms would
be exiting as the low level jet and SRH increase.

The models show a continued warm air advection pattern persisting
through the night allowing the dryline to return west. RAP and NAM
show a narrow east to west axis of isentropic assent developing
overnight within the moisture return. So have continued with some
small POPs through the early morning to account for the chance some
elevated storms develop. Forecast soundings still show around 2000
J/kg of elevated CAPE with 40KT of bulk shear. So there may be a
hail and/or damaging wind risk through the early morning hours.
Confidence in elevated storms is low since CAMs don`t really support
the RAP and NAM forecasts.

Saturday looks to be complicated by warm sector development ahead of
the dryline. Forecast soundings show little in the way of inhibition
by the afternoon as height falls spread east. So storm mode
could be complicated by this activity if it develops. The
environmental conditions look to remain favorable for supercell
storms with plenty of CAPE and shear. So we continue to message
the risk for severe weather including tornadoes which may have
the opportunity to be strong. There is a little more confidence
in another round of heavy rainfall over eastern parts of the
forecast area through Saturday night. A few river points went
into flood this morning and the additional rainfall will
probably may flooding a more widespread concern. With this in
mind, went ahead and posted a flood watch for Saturday afternoon
through Sunday morning.

The storm system responsible for all of the weather is progged
to remain over the central plains Sunday with another shortwave
trough rotating through eastern KS. A diffuse boundary is
forecast to still be over eastern KS through peak heating so
there remains a chance for one more round of thunderstorms
Sunday afternoon and into the early evening.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1201 AM CDT Fri Apr 26 2024

MVFR stratus will continue to mix out this morning leaving a
scattered CU deck that should be generally above 3KFT for the
rest of the day. Confidence in TS development and location is to
low to include in the forecast with CAMs not showing a
consistent picture. So will monitor trends. Low stratus is
forecast to move back into the terminals after 06Z with the
dryline retreating west overnight.

Wanted to add that forecast soundings are showing a strong low
level jet developing around 06Z. But the boundary layer looks to
remain somewhat mixed with winds remaining unidirectional. So
probabilities for LLWS appear to be low and only for a few hours
during the overnight.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Flood Watch from Saturday afternoon through Sunday morning for
KSZ011-KSZ012-KSZ023-KSZ024-KSZ026-KSZ037-KSZ038-KSZ039-KSZ040-
KSZ054-KSZ055-KSZ056-KSZ058-KSZ059.

&&

$$

DISCUSSION...Wolters
AVIATION...Wolters