334
FXUS63 KTOP 300829
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
329 AM CDT Tue Apr 30 2024

.KEY MESSAGES...

- A period of active weather is expected starting this afternoon
  and continuing through Thursday with several chances for
  thunderstorms, including the potential for severe weather.

- Additional rounds of thunderstorms could lead to heavy
  rainfall and the potential for flooding.

&&

.DISCUSSION...
Issued at 329 AM CDT Tue Apr 30 2024

Early this morning a 700 mb trough was progressing eastward out of
Colorado into western Kansas at 08Z. Scattered mid level showers
have developed within the nose of the 700mb warm advection. In
addition profilers and water vapor show small weak perturbations
that will move across eastern Kansas early this morning. The
scattered high based showers may have some lightning at times as
they progress eastward. They should come to an end by mid morning in
northeast Kansas.

Focus then turns to this afternoon as a mid level trough begins to
move across the northern and central Plains then into the upper
midwest later this evening. A mass response ahead of the wave and
associated cold front with dewpoints increasing into the lower 60s
this afternoon. General consensus with short term convective
allowing modes is for storms to develop across Nebraska and Iowa
this afternoon, with storms developing along the cold front and
dryline in central Kansas with additional development into northeast
Kansas by late afternoon. Forecast soundings and hodographs support
all modes of severe weather this afternoon and evening with large
hail perhaps 2 inches or higher, 70 mph wind gusts and tornadoes.
The line of storms will move southeast through northeast and east
central Kansas this evening with the front and convection then
stalling across southeast Kansas. Given this scenario will hold off
on a Flood Watch for now with the heaviest precipitation expected to
be near the Oklahoma border. Highs today will warm into the low to
mid 80s.

Later tonight looks quiet with the convection expected to remain
south of the forecast area over southern Kansas. However this will
be short lived as the front moves northward on Wednesday in response
to another mid level wave moving eastward across the Rockies and low
pressure deepening on the lee of the Rockies in southeast Colorado.
The front is forecast to lift into southern Nebraska or far northern
Kansas during the evening. Dew points in the 60s will spread
northward behind the warm front across the area. Convection is
expected to develop near the warm front from south central into
northeast Kansas early and looks to be elevated with mainly a hail
threat. Also good moisture flux into the region will also lead to
efficient precipitation with rainfall rates of 1 to 2 inches per
hour possible. By late afternoon storms may develop off the dryline
taking on supercell characteristics. The environment will be
favorable to all modes of severe weather once again with large hail
around baseball size, damaging winds to 70 mph and with good turning
in the lower atmosphere where effective SRH of 200-250 M2/S2 is
forecast would support strong tornadoes. Locally heavy rainfall
looks to set up Wednesday night into Thursday morning with training
cells along and ahead of the frontal boundary with in a PW axis of
1.5 inches, a theta axis bisecting the cwa from southwest to
northeast and strong moisture transport. This period will need to be
monitored for a future flood watch as well.

The mid level trough will move across the central Plains during the
afternoon hours Thursday and into Thursday evening. Additional
storms may develop along the frontal boundary over eastern Kansas in
the afternoon and evening hours. A continued risk for severe weather
and locally heavy rainfall is expected.

Additional waves moving through the flow across the Plains will
bring continued chances for precipitation this weekend into early
next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1224 AM CDT Tue Apr 30 2024

VFR conditions are expected for much of the period. A line of
TSRA is forecast to develop near MHK around 22Z then progress
southeast to TOP and FOE in the 23Z-02Z time period. Added VCTS
for now as convection will be scattered in that period. Winds
increase to around 15kts with gusts to 24kts by 15Z, then
increasing to around 23kts with gusts to 34kts by 19Z. Winds
decrease as the front approaches and become southwest. At MHK
winds will shift to the west then northwest around 10kts by 00Z
Wednesday as the front moves through. Winds decrease at TOP and
FOE by 02Z from the southwest around 10kts.

&&

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

&&

$$

DISCUSSION...53
AVIATION...53