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FXUS63 KTOP 231123
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
623 AM CDT Sun Jun 23 2024

.KEY MESSAGES...

- Slightly less hot today, but heat indices of 105-110 degrees are
forecast Monday and Tuesday. Heat Advisory has been issued for
Monday.

- Storm chances increase late Monday night through Tuesday with the
greatest focus on Tuesday night in eastern KS.

- Mainly overnight storm chances midweek through the weekend
  with lower temperatures, except Friday when triple digit heat
  indices may return.

&&

.DISCUSSION...
Issued at 400 AM CDT Sun Jun 23 2024

Early morning water vapor imagery shows the upper ridge encompassing
the southern CONUS with a shortwave trough over southern Manitoba
followed by another trough off the coast of British Columbia. This
places the main westerlies north of the forecast area where they are
expected to remain throughout the forecast period. At the surface,
high pressure sits over central NE behind yesterday`s front which
has now passed to the southeast of the CWA. This sfc ridge is
progged to move across the area throughout the day, turning winds
from the north back to the south this afternoon under sunny skies.
Slightly lower temperatures in the 90s and dew points in the 60s
should give us a short reprieve from the triple digit heat indices
today.

Low-level southerly flow increases into Monday with a strengthening
pressure gradient over the area, as a lee sfc trough develops in
response to a subtle perturbation rounding the periphery of the
upper ridge. This in addition to deeper mixing should allow for
850mb temps of 24-28C to mix down, yielding highs in the upper 90s
to low 100s, hottest toward central KS where mixing is deeper. Heat
indices of 105-110 are forecast area-wide, so have issued a Heat
Advisory for Monday afternoon. The aforementioned perturbation in
the flow aloft looks to pass near or north of the area late Monday
night into early Tuesday, so have low-end PoPs for this after
midnight through Tuesday morning. Similar temperatures and dew
points to Monday are forecast for Tuesday, so heat headlines may
again be needed. Consideration was given to issuing an Excessive
Heat Watch spanning Monday and Tuesday with a few places possibly
seeing heat indices near 110 both days and Tuesday morning lows only
falling to the mid to upper 70s, providing little nighttime relief.
However, confidence in reaching warning criteria is not high enough
at this time, especially if there is enough convection or cloud
cover in the morning to keep temperatures lower than forecast on
Tuesday. Trends will continue to be monitored to determine what type
of headline would be needed.

Greater chances for thunderstorms come Tuesday evening as a
shortwave moves through the Upper Midwest and drags a cold front
through the region. The best forcing looks to be north and east of
the area, leading to higher PoPs (50-60%) focused in eastern
locations Tuesday evening. Still, a very unstable air mass with deep-
layer shear around 30 kt leads to at least some potential for any
stronger storms to have damaging wind gusts. This risk should
diminish later in the evening as inhibition increases.

The pattern Wednesday through the weekend favors periodic
thunderstorm chances mainly during the overnight periods as upper
ridging holds to our south and embedded perturbations move through
the flow aloft. Exact timing and placement with each of these waves
is uncertain this far out due to the low-predictability nature of
this type of pattern. High temperatures look to hold in the 90s
Wednesday onward behind the front, with the exception of Friday when
a thermal axis may move overhead and bring heat indices back into
the 100s.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
-- Changed Discussion --
Issued at 622 AM CDT Sun Jun 23 2024

VFR conditions continue with light north winds this morning
veering to the SSE this afternoon, where they will remain the
rest of the period.
-- End Changed Discussion --

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from 1 PM to 7 PM CDT Monday for KSZ008-KSZ009-
KSZ010-KSZ011-KSZ012-KSZ020-KSZ021-KSZ022-KSZ023-KSZ024-KSZ026-
KSZ034-KSZ035-KSZ036-KSZ037-KSZ038-KSZ039-KSZ040-KSZ054-KSZ055-
KSZ056-KSZ058-KSZ059.

&&

$$

DISCUSSION...Picha
AVIATION...Picha