903
FXUS63 KTOP 131121
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
621 AM CDT Wed May 13 2026

.KEY MESSAGES...

- There is a 15-30% chance of showers and storms Thursday morning and
  again Thursday evening.

- Hot and humid weather is forecast Friday through Sunday giving a
  taste of summer before a cold front moves through Monday. Scattered
  showers and storms will be possible Friday through Monday, some of
  the storms could be strong to severe.

&&

.DISCUSSION...
Issued at 337 AM CDT Wed May 13 2026

Early this morning, water vapor satellite and upper air analysis
showed an upper level trough centered north of Lake Superior, with a
trough axis extending south-southwest into the mid MS River Valley.
A amplified upper ridge axis extended from northern Mexico/west TX,
north-northwest across the central Rockies. An upper level trough was
moving onshore across the Pacific Northwest. The Plains were under
northwesterly mid and upper level flow.

The 6Z surface map showed a cold front extending from southern MI,
southwest across central IL, southwest across central MO, into
southeast KS, then southwest into the TX PNHDL and northeast NM.
Light northeast winds were observed across the CWA with temperatures
in the mid 50s north to lower to mid 60s central and south.

Today through Tonight:

The H5 ridge across the central Rockies will move east across the
Plains. Expect mostly sunny skies with light winds becoming
southeasterly through the late afternoon hours. Highs will be
slightly cooler with upper 70s to lower 80s. The surface front will
stall out across OK and undergo frontolysis Tonight A southerly low-
level jet of 40 to 45 KTs will develop across central KS and advect
residual Gulf moisture northward into central KS. There may be enough
isentropic lift to the east of the moist(theta-e) axis for a few
isolated showers and storms to develop late Tonight and into the
early morning hours of Tuesday. Several CAM solutions show 200-500
J/KG of MUCAPE across the CWA, so some of the stronger elevated
storms may produce small hail as they move east across the area
during the early morning hours of Thursday.


Thursday through Friday night:

The morning showers and storms will weaken as the isentropic lift
diminishes by the mid morning hours and shifts east into MO.
The H5 ridge will shift east across the lower mid MS River valley.
The Pacific Northwest H5 trough will move east across the Great
Basin into the northern highs Plains. A stronger mid level
perturbation on the south side of the H5 trough axis will move east
into western NE/KS. Southerly winds will advect richer moisture
northward across central and eastern KS. A surface low will develop
across northwest/north central KS by afternoon. The surface dryline
will shift east across southwest KS into central KS (or at least a
pre-dryline surface trough). Surface convergence and ascent ahead of
the H5 perturbation may cause a few thunderstorms to develop. The
effective shear of 40 to 50 KTS along with MLCAPE of 2000-2500 J/KG
across central and north central KS would be favorable for supercell
thunderstorms, which could produce large hail, isolated damaging
wind gusts and possible tornadoes, given curved hodographs. However,
the capping inversion looks strong and this may suppress deep moist
convection from developing. The NAM12 shows no convection developing
Thursday afternoon along the dryline but the ECMWF and GFS do show
QPF across the western counties. If scattered supercells develop they
may merge into line segments and move east across northeast and east
central KS during the overnight hours. But if the Cap is strong any
isolated storms may dissipate a few hours after sunset.

Friday into Saturday night:

The stronger mid level flow will shift northward into NE. An upper
trough will dig southeast across the western US. A weak cold front
will drift south into the northern counties of the CWA, and if the
CAP is weaker, scattered thunderstorms will develop. Once again the
Nam12 shows no convection developing across the CWA Friday afternoon
into Friday night. The 850mb winds look more veered but surface winds
may be easterly along the stationary front. MLCAPES will increase to
2000- 3000 J/KG and the effective shear will be around 30 KTS across
the northern counties, so there could be supercell thunderstorms
developing north of I-70, if the CAP breaks. The primary hazard will
large hail and damaging wind gusts.

Sunday through Tuesday:

The western H5 trough will dig southeast into the southwestern US.
The strong southwesterly mid level flow will increase the effective
shear across the Plains. There will be chances for scattered
thunderstorms through the period. The better chance may be across
west central KS, north into NE Sunday afternoon into Sunday night.
As the H5 trough moves closer to the central and southern high Plains
the dryline will push farther east into central KS and a surface
cold front will move southeast into north central KS Monday
afternoon. The combination of surface convergence ahead of the front
and dryline should provide the CWA with better chance for
thunderstorms. The effective shear will be strong along with MLCAPES
in the 2000-3000 J/kg range may provide an environment for supercell
thunderstorms, with all hazards possible. If the front pushes faster
to the southeast, then the linear convergence may be more favorable
for a line of severe thunderstorms, where damaging wind gusts would
be the primary hazard.

The front will push southeast of the area Monday night, that should
bring an end to any strong to severe thunderstorms. The H5 trough in
the southwest will begin to fill and shear out. The elevated showers
and thunderstorms will continue as DCVA ahead of the H5 trough
continues to overspread the CWA. There may be some beneficial
rainfall on Monday with occasional elevated thunderstorms that do
not look to be severe. The rain and elevated thunderstorms should
shift east of the area Tuesday evening. Highs on Tuesday will be
cooler with periods of rain and northerly winds, with highs in the
lower to mid 70s.

The GFS and Canadian models are faster moving the front southeast of
the CWA by Sunday evening and do not show the stronger forcing for
post frontal showers and elevated thunderstorms northwest of the
front on Tuesday like the ECMWF solution.

It will be best to keep updated on the severe weather risks this
weekend into Monday.

Tuesday night through Wednesday:

A surface ridge of high pressure will move southeast across eastern
KS. An H5 ridge will amply across the high Plains as the sheared
out southwest H5 trough lift northeast across NE and phases with
another H5 trough digging southeast across the Great Lakes. Highs
Wednesday will reach into the upper 70s to lower 80s

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 618 AM CDT Wed May 13 2026

Expect VFR conditions through the next 24 hours. light northeast
winds will gradually back to the east and southeast Tonight. Wind
speeds will be under 10 KTS. Scattered mid level clouds will may move
over the terminals towards 12Z TUE. There may also be a few showers
and isolated thunderstorms towards 12Z TUE.

&&

.CLIMATE...
Issued at 340 AM CDT Tue May 12 2026

Record High Temperature for May 15

                 Record (Year)           Forecast
Topeka           95 (1944)               93
Concordia        91 (1944, 2012)         94


Record High Temperature for May 16

                 Record (Year)           Forecast
Topeka           95 (1931)               90
Concordia        93 (2019)               93

&&

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

&&

$$

DISCUSSION...Gargan
AVIATION...Gargan
CLIMATE...Drake/Gargan