963
FXUS63 KTOP 202339
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
639 PM CDT Mon May 20 2024

.KEY MESSAGES...

-Isolated to widely scattered thunderstorms will be possible this
 afternoon and evening. A few storms could be severe.

-Another round of severe thunderstorms are expected to develop
 along a front in far eastern KS Tuesday afternoon. Storms may
 develop just east of the area.

-An active pattern keeps POPs in the forecast later this week
 and during part of the holiday weekend.

&&

.DISCUSSION...
Issued at 259 PM CDT Mon May 20 2024

This afternoon, a weak surface boundary is sitting across
western KS in between low pressure over western IA and near the
TX panhandle. Light southerly winds in eastern KS have been
advecting higher dew points into the area today and there have
been a few showers and storms on radar at times. Isolated to
widely scattered storms will remain possible this afternoon and
this evening with some isentropic ascent over the area.
Instability has increased to near 3000 J/kg in central and
eastern KS, but shear remains on the weak side with fairly light
winds at the surface and aloft. However, given the amount of
instability, any storm that develops could produce damaging wind
gusts and small hail. More widespread severe weather is
expected north of the area, primarily in Nebraska near the
surface front this evening and tonight.

The aforementioned surface boundary will begin to move eastward
through the forecast area tomorrow as a shortwave trough rides
through the southwest flow aloft. Instability will remain high with
a hot and humid air mass in place. However, soundings show a stout
EML, which erodes in eastern KS just ahead of the boundary during
the early afternoon hours. Convective initation is expected along
the boundary as CIN diminishes somewhere in eastern KS or far
western MO. Storms could quickly become severe with all modes
of severe weather initially possible. Storms should then quickly
push eastward. Most CAMs show development occurring just east
of the CWA, but timing will have to be monitored closely.

A surface ridge moves in on Wednesday, which should make for a nice
spring day. Temps will be a little cooler with highs in the 70s.
POPs begin to increase once again by Thursday with theta-e advection
occurring while the ridge moves east and return flow sets up.
Long range deterministic models show a surface boundary in or
near the area for much of the extended forecast timeframe
(Friday-Sunday). Southwest flow aloft looks to remain in place
through much of the upcoming holiday weekend, so any subtle wave
in the flow could trigger scattered storms, especially near a
lingering surface boundary. Trends will be monitored each day
for updates to chances and timing.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 634 PM CDT Mon May 20 2024

The broken to scattered stratus/stratocu should dissipate near
and after sunset. There will continue to be periods of high
clouds. Cumulus clouds may redevelop tomorrow afternoon with
bases above 5000 feet. A LLJ will increase after 8z to 45 KTS
from the south-southwest. If surface winds are under 10 KTS,
then low-level windshear of 30 to 35 KTS will be possible from
8Z through 14Z. Once the PBL mixes deeper southerly winds will
increase to 15 to 20 KTS with gusts of 25 to 30 KTS and that
will extend through the afternoon hours. A wind shift will move
through the terminals after 22Z TUE, shifting winds to the west
then northwest.

&&

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

&&

$$

DISCUSSION...Teefey
AVIATION...Gargan