Hail and Damaging Winds in Kansas, June 11 to 12, 2018

Area Forecast Discussion
National Weather Service Topeka KS
819 PM CDT Mon Jun 11 2018

.MESOSCALE DISCUSSION...
Issued at 752 PM CDT Mon Jun 11 2018

Convection has begun to backbuild to the southwest along the cold
front near the KS/NE state line. MLCAPE on the order of 4000 J/kg per
the TOP 00z sounding still supports the potential for large hail
over the next few hours. Rapidly developing updrafts within the
extreme instability has caused enhanced stretching of the pre-
existing vorticity along the cold front/cold pool, which has
resulted in a few tornadoes in southeast NE. Recent short-term
model guidance is trending towards an increase in the effective
SRH with values reaching 200-300 m2/s2 as the low-level jet
strengthens. This environmental SRH along with the baroclinic
generated vorticity associated with the leading of the gust front
fosters the threat for tornadoes to continue through the late
evening. The latest analysis also shows DCAPE of 1500 J/kg ahead
of the mesoscale convective complex that could favor damaging wind
gusts through the early morning. Also, the warm moist air mass in
place may prohibit rapid cooling of the boundary layer, which
could limit the strength of the nocturnal inversion increasing the
likelihood of severe wind gusts to reach the surface.

&&

.SHORT TERM...(This evening through Tuesday)
Issued at 311 PM CDT Mon Jun 11 2018

A surface boundary was noted across central Kansas this afternoon
with temperatures soaring into the upper 90s ahead of this feature.
With dewpoints in the lower 70s and steep mid-level lapse rates,
vast instability has overspread northeast Kansas with CAPE over 4000
J/kg.  The front is expected to progress eastward this evening with
thunderstorms initiating in Nebraska, building down into the CWA.
With initial storms forming along the boundary, helicity values
indicate a tornado will be possible although the better chances look
to be north of the area in Nebraska.  The main hazards with storms
this evening may be strong winds and hail as storms begin to cluster
and become cold pool driven.  Storm motion will be on the slower
side and with PWAT values above average (2 to 2.5 inches) ahead of
the boundary, heavy rainfall may be another concern as storms form
parallel to the boundary.  Even with the potential for some training
storms, flooding should remain isolated as the front steady
progresses southeast. CAMs have been in decent agreement with
initial storms forming near the Kansas/Nebraska boarder and moving
southeast across the entire area.  The bulk of precipitation is
expected to be south of the area after roughly 2AM this morning,
with the HRRR indicating the potential for some lingering showers
and storms in east central Kansas through the early morning.

Not too much relief in the form of temperatures Tuesday after this
frontal passage with highs tomorrow in the upper 80s and low 90s.
Dewpoints may be slightly cooler and heat indicies will stay below
100 degrees.  Dry conditions are forecast through the afternoon as
high pressure noses in from the north (centered over South
Dakota).

.LONG TERM...(Tuesday night through Monday)
Issued at 311 PM CDT Mon Jun 11 2018

For Tuesday night into Wednesday morning, elevated thunderstorms
are possible. Models show upslope flow into the central high
plains which could favor convective development west of the area.
Then by Tuesday evening, models expect an 850MB front to be east
to west across the forecast area with the low level jet providing
convergence along the boundary. The better moisture and
instability is expected to be mainly across southern KS, but
storms could impact areas along and south of Interstate 70 where
the 850MB boundary is progged to be. Another round of elevated
storms is possible Wednesday night as models develop return flow
with the low level jet nosing into northeast KS.

By Thursday afternoon, mid level heights are expected to rise as
models develop ridging over the central plains. This ridging is
expected to persist through the weekend with little to no dynamic
forcing affecting the forecast area. So hot and dry weather is
forecast for Thursday through Sunday with lows in the 70s and
highs in the mid to upper 90s. There is heat concerns for this
time period as there could be a string of days with heat indices
approaching 105 degrees.

There are signs of a frontal system moving into the plains Sunday
night or Monday. Because of this there are some low end POPs
Sunday night and Monday. However confidence in this frontal timing
is low as the ECMWF wants to maintain the upper ridge over eastern
KS.

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 639 PM CDT Mon Jun 11 2018

Will maintain a watch for convective trends this evening as cells
develop along a frontal boundary. Additional storms may move south
out of Nebraska. Current thinking is for TSRA near MHK by 02Z and
at TOP and FOE around 03Z. Short term models suggest that the
storms may move south of the terminals by 06Z. Winds will shift to
the northwest behind the frontal boundary.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

MESOSCALE...Sanders
SHORT TERM...Heller
LONG TERM...Wolters
AVIATION...53

Hazardous Weather Outlook
National Weather Service Topeka KS
405 PM CDT Mon Jun 11 2018

KSZ008>012-020>024-026-034>040-054>056-058-059-122115-
Republic-Washington-Marshall-Nemaha-Brown-Cloud-Clay-Riley-
Pottawatomie-Jackson-Jefferson-Ottawa-Dickinson-Geary-Morris-
Wabaunsee-Shawnee-Douglas-Lyon-Osage-Franklin-Coffey-Anderson-
405 PM CDT Mon Jun 11 2018

This hazardous weather outlook is for east central...north
central and northeast Kansas.

.DAY ONE...Tonight.

Thunderstorms are possible this evening continuing through tonight.
Some of these may be severe and produce large hail and damaging
winds.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Strong to severe thunderstorms are possible Tuesday night,
primarily along and south of Interstate 70. Strong to severe
storms are also possible Wednesday night, primarily north of
Interstate 70.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed through tonight.

&&

More detailed information can be accessed at...
http://www.weather.gov/top/sitrep