524
FXUS63 KTOP 272155
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
455 PM CDT Sat Apr 27 2024

.KEY MESSAGES...

- Severe thunderstorms will the risk of all hazard types remain
  possible in the Tornado Watch area until 7pm. Additional
  storms may develop later this evening, especially across
  north central Kansas.

- A few strong storms could develop again Sunday in eastern KS as a
front continues to move through the area.

- Active pattern continues through next week with several more
  chances for showers and thunderstorms.

&&

.UPDATE...
Issued at 451 PM CDT Sat Apr 27 2024

Cancelled most of the Tornado Watch as the environment has
become more stable and further development is not anticipated
over the next several hours. As the low-level jet increases
tonight and upper-level ascent from the low pressure system
currently over far southwest Kansas begins to push eastward,
additional storms may develop along the warm front later this
evening.

Additionally, a High Wind Warning has been issued for 60-80 mph
winds associated with a wake low across Riley, Pottawatomie and
Wabaunsee Counties. Several semi trucks have been blown over on
highways.

&&

.DISCUSSION...
Issued at 412 PM CDT Sat Apr 27 2024

Mid-level trough has been moving through the Four Corners region
throughout the day. Associated sfc warm front has been slowly
pushing north across the forecast area, and is near the KS/NE border
as of 20Z. The dryline appears to be well southwest of the area,
although this has been obscured by the ongoing convection in
northern OK and south central KS moving northward into east central
KS. Our initial round of storms early this afternoon developed along
the warm front, and a wake low developed in southwest portions of
the area helping to push the boundary north. The outflow from this
initial activity has led to a substantial decrease in instability
across most of the area, with the exception of our far eastern
counties where there is still upwards of 3000 J/kg of CAPE. Any
additional severe storms at this point would need to be able to move
into those areas out of the cluster of storms coming from OK. The
CAMs are still suggesting repeated rounds of storms with heavy
rainfall to move through much of eastern KS this evening and
overnight, with another batch developing toward central KS towards
06-07Z. It is also around this time that Pwat approaches or exceeds
1.5", especially in east central KS. Decided to add Geary, Riley,
and Marshall Counties to the Flood Watch factoring in the initial
round of storms today plus recent trends in the CAMs, suggesting
those areas could see more locally heavy rain through the overnight
hours. Still have highest confidence in east central locations,
however.

Heading into Sunday, the upper low is still progged to be in NE/SD
with the sfc low progressing northeastward through KS/NE. While
parameters don`t look nearly as high as they did for today,
instability and shear would again be supportive for severe weather
for any storms that develop in eastern KS ahead of the cold front.
Will need to also monitor how well the atmosphere is able to recover
following the overnight convection after it moves out, but forecast
soundings at TOP currently suggest capping should erode by 18-19Z.
Any storms that develop should move out of the area through the
evening.

Monday looks to be the one dry day in the upcoming week before an
active pattern commences once again. Broad upper troughing is
progged to develop across much of the northwestern CONUS and deepen
over the western US by mid-week. Multiple perturbations within that
flow aloft lead to chances for showers and thunderstorms Tuesday
onward during the work week. Timing and placement of any of these
storms are uncertain this far out.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1250 PM CDT Sat Apr 27 2024

Main aviation concern is with thunderstorms in the first half of
the period, which have the potential to be severe. Storms have
already developed along a line from Salina to Sabetha near the
warm front. These may stay just north of the MHK terminal
initially, but with additional storms expected to move in from
south central KS and more development possible in the warm
sector, have gone ahead with a tempo TSRA at MHK for a few hours
this afternoon. Otherwise, storms should continue to move east
toward the Topeka terminals later this afternoon into the
evening, although guidance remains mixed on exactly when and how
quickly they move into east central KS. With this in mind,
amendments will need to be made as necessary. It`s tough to
pinpoint any point in time when there could be any breaks in
convection through the evening and overnight, though there
should be an end to the activity by early morning. MVFR cigs
look to make a return late tonight, likely not scattering until
after this period.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Flood Watch through Sunday morning for KSZ010-KSZ011-KSZ012-
KSZ022-KSZ023-KSZ024-KSZ026-KSZ036-KSZ037-KSZ038-KSZ039-KSZ040-
KSZ054-KSZ055-KSZ056-KSZ058-KSZ059.
High Wind Warning until 7 PM CDT this evening for KSZ022-
KSZ023-KSZ038.

&&

$$

UPDATE...Jones
DISCUSSION...Picha
AVIATION...Picha