937
FXUS63 KTOP 022326
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
626 PM CDT Thu May 2 2024

.KEY MESSAGES...

- A brief period of dry weather for Friday is expected before a
  front brings thunderstorm chances back Friday night and
  Saturday AM. These could be strong to severe with small hail
  and damaging winds being the main concerns.

- A few systems move across the Plains this weekend, continuing
  chances for rain and thunderstorms, mainly south of I-70.

- Large trough moves in Monday and Tuesday bringing another
  chance for strong to severe storms across the area.

&&

.DISCUSSION...
Issued at 247 PM CDT Thu May 2 2024

This morning and early afternoon has seen a frontal boundary move
across the area, giving way to scattered showers and thunderstorms.
This boundary is currently situated just southeast of our area and
continuing its way southeast. Over the past hour, scattered elevated
thunderstorms have developed in southeastern KS on the northern
periphery of a MCV that is moving across northeastern Oklahoma. With
pockets of solar insolation ahead of the frontal boundary, MUCAPE
has been able to build to around 1000 J/kg (via SPC mesoanalysist)
with RAP 0-6 km shear approaching 30-35kts. With the enhanced shear
from the MCV and increasing marginal levels of buoyancy, cannot rule
a strong updraft yielding some pea to nickel-sized hail this
afternoon for areas south of I-35. Instability should quickly push
east as the frontal boundary continues east, so do not expect a
prolonged period of storms in this area.

Precipitation chances for far eastern Kansas fizzle out by this
evening at the latest with surface ridging building into the area. A
much anticipated dry and sunny day comes Friday with temperatures
warming into the mid-70s by the afternoon. These conditions will not
last long as a shortwave pushing across the north Plains slides a
frontal boundary through Kansas Friday evening and overnight into
Saturday morning. A brief window of moisture advection should take
place across central Kansas as the low-level ridge axis moves east
of the area Friday morning. This should be enough to increase
instabilities ahead of the boundary to the 1000-1500 J/kg range.
With deep shear maximized closer to the upper-level jet in Nebraska,
north-central and far northeastern Kansas seem like the areas where
shear and instability align for strong to severe storms along the
front to become possible. Steep lapse rates could also help to make
up for the lack of instability helping to pose a threat for damaging
winds and quarter-sized hail. As the boundary moves further into
eastern Kansas, shear should decrease as the main upper low pushes
into the Great Lakes region. This will likely weaken convection as
cool-pool circulation becomes unbalanced. Residual precipitation
behind the system will move out by Saturday afternoon, ushering in
another brief dry period into Sunday morning.

A shortwave moving in from southwestern TX ejects into Oklahoma and
southern Kansas Sunday afternoon that increases rain and elevated
thunderstorm chances into Sunday evening. The main QPF axis stays
closer to the surface low that deepens across central Oklahoma, but
moisture advection north of the warm front in northern OK and
southern KS could bring rain and storm chances into areas south of I-
70 (40-60%). Guidance keeps better instability and shear south of
our area so not expecting too much in the way of severe weather with
this wave.

The next widespread chance for strong to severe thunderstorms ushers
in with a long wave trough axis digging out of the 4-corners region
Monday into Tuesday AM. A large warm sector will develop across much
of the central Plains with the set-up likely to produce severe
weather across the Plains. There still are some discrepancies with
positioning of the main upper-low and will play a role in
determining where better low-level dynamics set up. Regardless, keep
an eye on the forecast in the coming days as this system appears to
have the ingredients for severe weather to occur across the area
Monday afternoon into Tuesday AM.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 624 PM CDT Thu May 2 2024

VFR conditions have returned with gradual clearing expected this
evening and overnight. Some light radar returns can be seen near
and northeast of Topeka sites, but with no evidence of lightning
nearby and instability moving southeast, have decided to remove
the remaining VCTS and continue to monitor. Otherwise, light
NNE winds tonight eventually turn back to the southeast and
increase above 10 kt Friday afternoon as high clouds move back
in.

&&

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

&&

$$

DISCUSSION...Griesemer
AVIATION...Picha