Special Weather Statement, NWS Topeka, KS

Area Forecast Discussion
National Weather Service Topeka KS
1238 AM CDT Wed Oct 13 2021

...Update to aviation forecast discussion...

.DISCUSSION...
Issued at 218 PM CDT Tue Oct 12 2021

Severe storms are anticipated this evening late and into the
overnight period as a line of storms move into the area from western
Kansas.  Key takeaway is be able to receive warnings during the
overnight period as the strongest storms are likely after midnight
and especially over areas along and west of a line from Manhattan to
Marysville.

The forecast appears to be on track as the well advertised Pacific
system has deepened and is near maturity over the Desert Southwest.
Lee troughing and strong gradient flow continue to advect deeper
moisture north with near 60 dewpoints now close to the southwestern
KS and OK panhandle region.  Isentropic ascent ahead of a lead
shortwave has helped keep a line of elevated showers and embedded
storms in place over western into central KS.  Meanwhile, the
synoptic cold front resides generally along the front range of the
Rockies into New Mexico. This is forecast to continue to sharpen and
advance east as the upper low lifts northeast and becomes negatively
tilted.

For the forecast area this evening, this does mean that severe
weather should eventually move into the area likely late overnight.
One condition that casts some doubt on how intense the storms remain
as they move into the area late overnight is the current plume of
moisture where the embedded showers and storms reside.  As the lead
shortwave of energy continues to track northeast, so will this area
of showers and storms.  The longer these reside over the area, the
less available energy may be available for overnight storms.
Regardless, there should be enough advection to partially offset any
loss of instability.  Storms from western KS should thus have plenty
of environmental shear to help updrafts remain organized along the
frontal boundary as it advances into the area.  Locations west of
Manhattan and Marysville line will have the best environmental
conditions in place to support severe damaging winds as again
forecast 0-3km shear vectors suggest 40-50kts in tandem with around
2,000 J/kg of MUCAPE.  Also, effective SRH has been forecast to be
as high as 400-500 m2/m2 over north central KS areas.  Thus, still
can't rule out a nighttime tornado threat but would likely remain
brief.  Hail would likely be isolated to the strongest storm cells.
Heavy rain should still see limited residence time over any one
area, so still not overly concerned with flooding aspects but some
localized areas could see short-term impacts as there is at least
some possibility that storms begin to slow eastward progression as
they move east into northeastern KS and east central areas.

As the trough lifts into the northern plains and central Canada, a
broad western trough remains in place along the spine of the
Rockies.  This will keep a quasi-stationary boundary just to the
southeast of east central KS into Thursday night and Friday.  Have
therefore kept POPs over the area longer during the day on Friday as
an embedded low amplitude wave lift into the area.  This should help
draw moisture back over the boundary with anafrontal type
precipitation.  This trough becomes more progressive into the
evening on Friday and cooler temperatures advect into the area which
could bring near frost conditions over especially northern areas
along the KS/NE border by Saturday morning.  A wonderful fall
weekend still appears in store after this as a low amplitude broad
ridge sets up for the weekend with plenty of dry air in place.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1237 AM CDT Wed Oct 13 2021

A line of storms will move across the area overnight into the
early morning hours, and this will be the main concern for this
period. Have MVFR cigs and vsby along with gusty south winds as
storms move through terminals, with cigs lifting and skies
clearing after they pass. Winds should turn to the WSW and
gradually become less gusty throughout the day, but remain
sustained in the 10-15 kt range until 23Z when they decrease to
around 5 kts.

&&

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

DISCUSSION...Drake
AVIATION...Picha

Hazardous Weather Outlook
National Weather Service Topeka KS
224 PM CDT Tue Oct 12 2021

KSZ008>012-020>024-026-034>040-054>056-058-059-131930-
Republic-Washington-Marshall-Nemaha-Brown-Cloud-Clay-Riley-
Pottawatomie-Jackson-Jefferson-Ottawa-Dickinson-Geary-Morris-
Wabaunsee-Shawnee-Douglas-Lyon-Osage-Franklin-Coffey-Anderson-
224 PM CDT Tue Oct 12 2021

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

.DAY ONE...Tonight

Thunderstorms are still expected to move west to east across the
entire area overnight tonight.  Severe weather is possible with
these storms. The main hazard will be widespread damaging winds
and possibly isolated large hail. A brief tornado or two can't be
ruled out especially over north central into central Kansas areas.
The best timing of severe storms is between midnight and 7 am
Wednesday. Be sure to have multiple ways to receive warning
information in case severe weather threatens after you've gone to
bed.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

Low temperatures in the middle 30s and frost is possible for
parts of north central Kansas Saturday morning.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed through tonight.

&&

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

Special Weather Statement
National Weather Service Topeka KS
1248 AM CDT Wed Oct 13 2021

KSZ008-020-034-130630-
Republic-Cloud-Ottawa-
1248 AM CDT Wed Oct 13 2021

...Strong thunderstorms will impact portions of western Ottawa,
Republic and Cloud Counties through 130 AM CDT...

At 1247 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 3 miles west of Hardy to 8 miles east of
Wilson. Movement was east at 45 mph.

HAZARD...Wind gusts of 40 to 50 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Concordia, Minneapolis, Belleville, Glasco, Scandia, Delphos,
Tescott, Jamestown, Courtland, Cuba, Norway, Culver, Republic,
Munden, Narka, Aurora and Ada.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 500 AM CDT for
north central Kansas.

&&

LAT...LON 4000 9737 3896 9765 3896 9793 4000 9793
TIME...MOT...LOC 0547Z 271DEG 38KT 4001 9799 3886 9832

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH

Gargan