755
FXUS63 KTOP 121729
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1229 PM CDT Wed Jun 12 2024

.KEY MESSAGES...

- Hot temperatures expected Thursday with heat indices in the
  afternoon near advisory levels.

- Severe storms are possible from late Thursday afternoon and
  evening.

- Periodic storm chances and above normal temperatures expected this
  weekend into early next week.

&&

.DISCUSSION...
Issued at 305 AM CDT Wed Jun 12 2024

Early this morning water vapor satellite showed a mid level trough
moving across Alberta Canada into northern Montana at 07Z. Midlevel
ridging over the Rockies will build into the southern Plains as a
low in the Pacific approaches Southern California. Main westerlies
are to remain to the north of Kansas today as heights gradually
rise. A frontal boundary will move southward tonight across the
central Plains as the above mentioned shortwave moves across
southern Canada as well as the northern states. Moisture gradually
increases later tonight and Thursday.

For today expect mostly sunny skies with temperatures generally in
the 75th percentile and averaging about 7 to 8 degrees above normal
yielding highs in the upper 80s to mid 90s. Lows tonight will be
mild with lows in the lower 70s.

Thursday the frontal boundary in  Nebraska Thursday morning
gradually moves southward into north central and northeast Kansas in
the afternoon hours. Heating south of the frontal boundary as well
as moisture pooling and the thermal axis building through the day
will yield temperatures in the 90s to low 100s. The combination of
heat and humidity will produce heat indices around 105 degrees
across much of the area, except for these areas north of the front.

Thursday late afternoon into the evening hours model forecast
soundings show CAPE increasing to 4000-5000 J/kg across the area
along, mid level lapse rates around 7.5 C/km and around 40kts of
shear. A capping inversion erodes by early evening allowing for
convection to develop along the front. Initially probabilities will
be in the 15-25% range with higher 35-40%) expected across northeast
Kansas into northwest Missouri. Main hazards will be hail and
damaging wind gusts as DCAPE of 1600-1800 J/kg is forecast. Isolated
cell may evolve into short line segments in the evening increasing
the wind threat.

The frontal boundary across southern Kansas on Friday morning is
forecast to lift north as a mid level trough moves across the
Rockies allowing for a mass response with a return of higher
moisture into northern Kansas. Increasing low level jet will aid in
the development convection Friday night across northern Kansas into
Nebraska. Another round of storms is possible Saturday evening and
night with the mid level trough moving east across the central
Plains. A mid level trough moving across the northern Plains Tuesday
and Tuesday night is forecast to bring another frontal boundary into
northeast Kansas keeping chances for storms in the forecast.

High temperatures remain above normal in the 90s from Friday into
early next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1229 PM CDT Wed Jun 12 2024

VFR conditions prevail. South-southwest winds gusting at 20-25kts
this afternoon weaken this evening. There could be some LLWS in
the 06-11z timeframe, especially if surface winds decouple more
than forecast. Winds gust to around 20kts again around 14z Thursday.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...53
AVIATION...Flanagan