564
FXUS63 KTOP 180521
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1221 AM CDT Tue Jun 18 2024

.KEY MESSAGES...

- Chance of thunderstorms Tuesday afternoon through Wednesday morning
will bring threat for severe thunderstorms and heavy rainfall.


- Highest confidence in 1-3" of rainfall will be north of a line from
Abilene to Manhattan to Seneca. Locally higher amounts possible.

- Storm chances dwindle Thursday as stalled boundary finally begins to
retreat north.

&&

.DISCUSSION...
Issued at 207 PM CDT Mon Jun 17 2024

Looking at the latest surface analysis, a strong pressure gradient
is driving gusty southerly winds across the state of Kansas. Strong
southerly winds are keeping dewpoints in the 70s, bringing yet
another hot and humid day. Winds will continue to gust between 30-40
mph this afternoon and overnight. They will be close to wind
advisory criteria, but confidence in widespread wind gusts of 45 mph
is very low.

Tomorrow, a strong upper-level jet rounds the base of a trough in
the northern Rockies, but most of the dynamic support will be
further to the north. Across north central KS, a convergent boundary
will be the focus for CI during the late afternoon tomorrow.
Initially, storms that form on the boundary will have access to
between 1000-2000 J/Kg of surface CAPE, supporting large hail and
damaging wind gusts. Effective shear of only ~20 kt along with good
frontal convergence will lead to upscale growth, and a transition to
clusters of storms with an increasing damaging wind threat. The
boundary is likely to stall, and outflow rushing out from under the
storms will lower the severe threat by late evening.

The main concern comes later in the evening and overnight, when
strong southerly flow will overrun a nearly stationary boundary,
providing a good environment for heavy precipitation and training
storms. PWAT values will be near the climatological maximum, between
1.75-2". Guidance varies on where the maximum band of heavy rain
will set up, but there is a high probability (70-90%) that portions
of North Central KS will see 1-2" of rainfall. The HREF mean is 2",
and amounts could locally reach 3-4". The area with the highest
chance of seeing this heavy rainfall is roughly north of a line from
Abilene to Manhattan to Seneca. Rainfall totals will drop off
significantly to the south of that line, and portions of east
central Kansas may see little to no rain.

Training thunderstorms will continue overnight through Wednesday
morning. As the trough lifts off Wednesday, the surface boundary and
any remaining outflows left behind could be a trigger for more
convection during the day. Shear will be weak, but high levels of
moisture remain in the atmosphere, and heavy rain will once again be
possible.

Thursday, the boundary finally lifts to the north and the area
becomes dry. Temperatures will remain above average for the period
except Wednesday, when cloud cover and precipitation will keep
temperatures at or below average. Perturbations in the flow may
provide additional storm chances through the weekend, but
predictability is low at this point.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1220 AM CDT Tue Jun 18 2024

South winds will continue through the period, strongest during the
daytime hours at 15-20 kts with gusts to around 30 kts. Ceilings
will stay primarily VFR, though there is still a few hour window
where some SCT to BKN MVFR ceilings will be possible during the
morning, most likely towards KMHK. By late evening, storms will
develop along a front in north-central KS, though this should
stay northwest of KMHK through midnight.

&&

.CLIMATE...
Issued at 211 PM CDT Mon Jun 17 2024

Record Warm Low Temperatures

June 17
               Record      Low as of 2 PM
Concordia     75 (2018)         75
Topeka        78 (1918)         76

June 18

               Record        Forecast
Concordia     80 (1953)         74
Topeka        81 (2021)         76

&&

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

&&

$$

DISCUSSION...Montgomery
AVIATION...Reese
CLIMATE...Montgomery