970
FXUS63 KTOP 240908
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
408 AM CDT Mon Jun 24 2024

.KEY MESSAGES...

- Heat Advisory is in effect from noon today through 8pm Tuesday,
with heat indices between 105-110 degrees.

- Thunderstorms are possible tonight through Tuesday night, with
highest confidence in eastern KS Tuesday evening. A few storms could
produce damaging wind gusts.

- More seasonal temperatures midweek through the weekend (except
  Friday) with mainly nighttime storm chances.

&&

.DISCUSSION...
Issued at 407 AM CDT Mon Jun 24 2024

Upper ridge is holding strong over the southern US with the main
westerlies over the northern third of the CONUS. A shortwave trough
is noted within that flow along the Canadian border with MT. A sfc
trough axis in response to that wave extends from eastern MT
southeastward through the High Plains.

Deep mixing up to 800-700mb will bring very warm temperatures aloft
down to the surface this afternoon. This in addition to increasing
southerly low-level flow supports high temperatures in the upper 90s
to near 100 in eastern KS and highs between 100-105 in central KS
where mixing is deeper. That mixing should result in lower dew
points in central KS compared to further east, but overall heat
indices are still forecast in the 105-110 degree range widespread
across the area this afternoon. Mixing doesn`t look nearly as deep
on Tuesday, but overnight lows only falling back to the mid to upper
70s in the morning means it wouldn`t take as much time to heat back
up to the upper 90s to low 100s again. The thermal axis looks to
remain over the area as well. Given that the vast majority of the
area is forecast to have heat indices in the 103-108 degree range
Tuesday afternoon, and warm lows in the morning will provide little
relief overnight, have opted to extend today`s Heat Advisory through
the night into Tuesday afternoon.

The one potential caveat to having widespread advisory conditions
Tuesday is related to whether or not we have morning convection that
would then lower temperatures for the afternoon. Confidence in
showers and thunderstorms tonight through Tuesday early afternoon is
rather low, however, considering the CAMs have varying ideas on
timing and placement and forcing for ascent is weak. Confidence in
storms increases later in the afternoon into the evening, and if
clouds and precipitation hold until then, very hot and humid
conditions would justify continuing the advisory.

Speaking of storm chances, late this afternoon and early this
evening, scattered storms look to develop in western NE/KS. These
are driven in part by a subtle perturbation rounding the upper ridge
and also by a weak frontal boundary developing in NE associated with
the system to the north. The NAM and NAM Nest have consistently been
farthest east with bringing convection through southeast NE into
northeast KS overnight into early Tuesday morning, whereas most
other guidance appears to favor western KS initially before bringing
storms into north central and northeast KS after dark. Given
variations among guidance to this point, have kept PoPs between 15-
25% between 00-12Z. Shear doesn`t look impressive (20 kt at best),
so wouldn`t expect storms that make it into this environment to be
severe. If something were to develop in north central KS in the late
afternoon, a well-mixed BL with an inverted-V profile could support
collapsing updrafts with damaging winds. However, the more probable
scenario is for storms to hold off until later in the evening when
inhibition increases and the environment no longer supports this.

Low-end PoPs continue through Tuesday morning and early afternoon,
but the more favorable setup for thunderstorms comes in the late
afternoon to evening as an upper wave passes to our northeast and
brings a frontal boundary through the area. Plenty of instability
exists ahead of this boundary and shear around 30 kt would better
support more organized updrafts. The main question becomes whether
there will be enough convergence along the front to overcome capping
and how widespread storms will be as a result. Any storms that
develop and can become organized would again pose a damaging wind
threat with collapsing updrafts.

Behind the front, relatively cooler temperatures are forecast for
Wednesday and Thursday with the upper ridge holding to our
southwest. Heat may return briefly on Friday with return flow
bringing higher temperatures and dew points, but uncertainty in the
forecast increases midweek onward as embedded perturbations
continually round the ridge and bring overnight MCSs through the
region each night Wednesday night through the weekend. Each wave
will likely impact the following one, so exact details on timing and
placement of each round should become clearer as we get closer to
each day. This could impact temperatures each day as well, leading
to lower confidence in Friday`s heat.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1228 AM CDT Mon Jun 24 2024

VFR conditions continue. Light S to SSE winds overnight veer
slightly by late morning and pick up to 10-15 kt sustained with
gusts 20-25 kt. Gusts should subside after sunset but sustained
winds look to remain up around 10 kt. Some short-term guidance
is trying to suggest convection may approach from central KS
late in the period, but confidence is low and chances are
overall better north and west of terminals. Will continue to
evaluate on future issuances.

&&

.CLIMATE...
Issued at 610 PM CDT Sun Jun 23 2024

Record hot temperatures are possible Monday and Tuesday

          Record High              Forecast High

June 24   Topeka: 104 (1937)       Topeka: 100
          Concordia: 106 (1937)    Concordia: 103

June 25   Topeka: 106 (1911)       Topeka: 98
          Concordia: 104 (1988)    Concordia: 100


          Record Highest Minimum   Forecast Minimum

June 25   Topeka: 82 (1911)        Topeka: 77
          Concordia: 80 (1952)     Concordia: 77

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Heat Advisory from noon today to 8 PM CDT Tuesday 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
CLIMATE...Poage