486
FXUS63 KICT 291740
AFDICT

Area Forecast Discussion
National Weather Service Wichita KS
1240 PM CDT Sat Jun 29 2024

.KEY MESSAGES...

- Scattered storms this morning, especially across the Flint Hills

- Another hot and humid day across south central and southeast KS

- Storms possible this afternoon/evening across southern KS; better
  chances tonight across portions of central/south-central KS

- Active weather pattern into next week with roller-coaster-like
  temperatures

&&

.DISCUSSION...
Issued at 308 AM CDT Sat Jun 29 2024

As of 3 AM, zonal midlevel flow was positioned across the central
Plains with a northern stream shortwave trough moving across the
northern Plains. A meandering surface trough extends from portions
of southwest KS to near Dodge City to McPherson to near Topeka. A
modest temperature gradient and wind shift reside along the frontal
zone. Two zones of convection were ongoing at this hour with the
first across northwest KS into central KS. This convection is
positioned on the midlevel lapse rate gradient, which extends
from eastern CO into central KS. Midlevel WAA has been weakening
and leading the this convection weakening as well. The second
zone resides across the Flint Hills and within a zone of WAA
rooted near 850 mb. The focal point for development thus far has
been on the nose of the jet or generally along Highway 50. RAP
and HRRR forecast soundings suggest parcels originating between
800-700 mb have up to 500 J/kg of instability. Effective shear
values are in the 20-30 kt range and should mitigate any
potential for severe storms. More notably, PW values remain near
2" and will support heavy rainfall. As the LLJ weakens towards
sunrise, convection should dissipate.

Transitioning into the daytime hours today,the frontal zone will sag
further south before stalling near the OK state line. Temperatures
north of Highway 50 should be notably cooler this afternoon
with highs in the 80s to near 90. Areas along and south of
Highway 400 are likely to see another afternoon of hot
temperatures and humid conditions. One of two scenarios (or a
combination of both) are likely to play out this afternoon.
Boundary layer mixing will ensue shortly after sunrise today.
Forecast RAP and HRRR soundings seem a bit overzealous with
mixing heights and subsequent surface dew points (and were
yesterday as well). Their raw outputs suggest temperatures will
surge near 100+ degrees along the OK border with dew points in
the mid to upper 60s. Even so, this still sends heat index
values near 105. Should dew points hold near 70 into the
afternoon, which seems plausible, heat index values near 110
would become likely. Immediately behind the frontal zone
(generally along Highway 400), boundary layer mixing will be
greatly reduced with dew point values likely to surge back into
the low-mid 70s. Combing this moist boundary layer with
temperatures in the mid-90s will create heat index values near
105. As a result, have opted to expand the Heat Advisory
northward to include Sedgwick, Butler, Greenwood, Elk, Wilson,
Woodson, and Allen counties. See the latest Advisory for further
detail.

In regards to the convection potential this afternoon, large
scale ascent will remain meager through the daytime hours,
although weak convergence along the front may yield a few
storms. Confidence continues to increase for convection
tonight, mainly across portions of central and south central KS.
This appears to be the zone where a 25-30 kt LLJ will
overspread the stalled frontal zone. Severe weather appears
unlikely but heavy rainfall is probable with any storm as PW
values remain near 2".

Heat relief is expected area-wide Sunday as the frontal zone
sinks further south into OK. In addition, showers/storms may
linger into the afternoon, especially across central/south-
central KS. Afternoon high temperatures near 80 are expected.

The heat will return area-wide Monday and Tuesday as the front
retreats northward and midlevel ridging amplifies overhead.
Temperatures will once again approach the 100 degree mark. A
northern stream trough will shunt the frontal zone southward into
our area late Tuesday into Wednesday. This will set the stage for
another break from the heat and additional storm chances through
Thursday.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 1150 AM CDT Sat Jun 29 2024

VFR conditions will start at all terminals but thunderstorms
later in the TAF period will make for difficult flying
conditions. Showers and thunderstorms with wind potential into
the 45Kt range are possible in the KCNU area between 23Z and 03Z
tonight but after that time, VFR conditions are expected to
rule. The remaining terminals, VFR conditions are expected until
close to 09Z to 11Z. KRSL and KSLN will likely see some showers
with embedded thunderstorms during this time while KHUT and
KICT will likely see this activity later in the 11Z to 14Z time
frame. The main terminal of concern will be KGBD which could
have several hours of thunderstorm activity. Very heavy rain is
likely but winds are not expected to be severe. This heavy rain
risk will significantly reduce VSBY conditions as a result.
AFter 16Z to 18Z tomorrow, VFR conditions will return to all
terminals.

&&

.ICT WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM CDT this evening for KSZ069>072-083-
091>096-098>100.

&&

$$

DISCUSSION...BRB
AVIATION...ELM