Special Weather Statement, NWS Topeka, KS

Area Forecast Discussion
National Weather Service Topeka KS
636 PM CDT Wed May 26 2021

...Update to aviation forecast discussion...

.DISCUSSION...
Issued at 337 PM CDT Wed May 26 2021

Latest water vapor satellite loop shows a mid level trough over
western Montana and western Wyoming at 1945Z. Profilers show some
perturbations emanating from the Rockies out into the high plains .
Surface analysis had a dryline in eastern Colorado along or just
east of the front range with a warm front extending from southeast
Wyoming through northwest Kansas and into central Kansas at 18Z.
Isolated storms continue to fire along the frontal boundary this
afternoon in an unstable and moist environment with around 40 kts of
effective shear. CAMS have had a difficult time resolving the
convection today as they have not done well with the development in
central Kansas along the warm front. Outflow from earlier convection
helped to increase convergence along the warm front for additional
storm development.

For tonight, the mid level wave will move eastward increasing
forcing for ascent across the central Plains. Expect storms to fire
along the front range still and then congeal into a forward moving
MCS across southern Nebraska and northern Kansas tonight. Storms in
central Kansas may weaken as they move into a less favorable
environment before reaching north central Kansas. Increasing low
level jet will increase moisture advection into central and eastern
Kansas tonight as seen in elongating moisture transport vectors.
High PW air will be somewhere between 1 and 2 inches tonight across
central and eastern Kansas. Expect high precipitation efficiency
with the storms as they move eastward and expect some training of
storms along the southwest flank of the MCS. Would not be surprised
to see some 3 plus inches in some locations tonight. WIll continue
with the Flash Flood Watch for tonight into Thursday morning. In
addition on the south flank of the convection forecast soundings
suggest storms may remain surface based with sweeping low level
profiles as seen in hodographs, keeping the threat for a few
tornadoes through a good portion of the night. Large hail and
damaging winds will be the main hazards with the convection.

Thursday will pose another challenge depending on how far south the
outflow boundary goes across the forecast area. Models suggest that
the front and outflow boundary may set up across parts of northeast
and east central Kansas near the Turnpike. Another round of severe
convection is expected across northeast and east central Kansas with
the higher probability near and south of the boundary in the
afternoon. Convection may develop by early afternoon and then move
southeast out of the area by early evening. All modes of severe
weather will be possible once again.

Dry weather with cooler temperatures are expected for Friday through
Saturday under the influence of a mid level ridge as well as a
surface ridge into northeast Kansas. Rain chances return late in the
weekend into early next week as a series of waves moves through the
nearly westerly mid level flow across the Plains. Highs will be in
the 60s to the lower 70s.

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 620 PM CDT Wed May 26 2021

VFR continues at KTOP/KFOE/KMHK with latest model guidance
anticipating isolated TSRA to impact KMHK as early as 01Z before a
more organized cluster of TSRA drops east and southeast from
southern NE after 06Z. Adjusted timing back some at terminals,
going prevailing with moderate TSRA and MVFR visibilities until
clearing from west to east in the 12Z to 14Z time frame.
Additional TSRA is possible near KTOP/KFOE aft 19Z, however
confidence remains too low for mention, dependent upon where the
boundary sets up. Winds increase and back towards the west
southwest during the afternoon Thursday.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch from 10 PM CDT this evening through Thursday
morning for KSZ012-024-026-038>040-055-056.

Flash Flood Watch through Thursday morning for KSZ008>011-
020>023-036.

&&

DISCUSSION...53
AVIATION...22

Hazardous Weather Outlook
National Weather Service Topeka KS
612 PM CDT Wed May 26 2021

KSZ008>012-020>024-026-034>040-054>056-058-059-272315-
Republic-Washington-Marshall-Nemaha-Brown-Cloud-Clay-Riley-
Pottawatomie-Jackson-Jefferson-Ottawa-Dickinson-Geary-Morris-
Wabaunsee-Shawnee-Douglas-Lyon-Osage-Franklin-Coffey-Anderson-
612 PM CDT Wed May 26 2021

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

.DAY ONE...Tonight.

Severe thunderstorms are forecast to move into north central
Kansas this evening and through northeast and east central Kansas
overnight. With storms expected to be in a large cluster,
damaging winds up to 80 mph and large hail up to golf ball sizes
are the primary hazards. Although a tornado can not be ruled out
if a discrete storm develops south of the main cluster.

The thunderstorms are forecast to be efficient rain producers as
well, with some locations possibly receiving 1 to 3 inches of
rain in a short period of time. Because of this, a flash flood
watch has been issued for tonight and into Thursday morning for
areas along and north of a line from Ottawa to Junction City.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday.

Severe thunderstorms could redevelop across east central Kansas
Thursday afternoon. Again large hail, damaging winds and very
heavy rainfall will be possible.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report any wind damage, large hail and rainfall
amounts over one inch to the National Weather Service in Topeka.

&&

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

Special Weather Statement
National Weather Service Topeka KS
559 PM CDT Wed May 26 2021

KSZ034-262330-
Ottawa-
559 PM CDT Wed May 26 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN OTTAWA COUNTY UNTIL
630 PM CDT...

At 558 PM CDT, Doppler radar was tracking a strong thunderstorm near
Beverly, moving northeast at 15 mph.

Nickel size hail and wind gusts of 50 to 55 mph will be possible with
this storm.

Locations impacted include...
Tescott and Ada.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3924 9793 3925 9792 3908 9767 3896 9781
      3896 9793
TIME...MOT...LOC 2258Z 222DEG 15KT 3907 9800

Special Weather Statement
National Weather Service Topeka KS
651 PM CDT Wed May 26 2021

KSZ020>022-034-270045-
Clay-Cloud-Riley-Ottawa-
651 PM CDT Wed May 26 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN RILEY...NORTHERN
OTTAWA...CLAY AND CLOUD COUNTIES UNTIL 745 PM CDT...

At 651 PM CDT, Doppler Radar was tracking strong winds from
dissipating showers that could gust up to 55 mph. It is possible you
may hear no thunder and have little to no rain with these strong
winds.

Locations impacted include...
Concordia, Clay Center, Riley, Miltonvale, Glasco, Leonardville,
Delphos, Morganville, Randolph, Green, Aurora and Idana.

A Severe Thunderstorm Watch remains in effect until 200 AM CDT for
north central and northeastern Kansas.

LAT...LON 3955 9793 3956 9673 3923 9676 3928 9793
TIME...MOT...LOC 2351Z 271DEG 44KT 3943 9723