Special Weather Statement, NWS Kansas City, MO

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
326 PM CDT Sat Sep 16 2017

.Discussion...
Issued at 326 PM CDT SAT SEP 16 2017

A band of showers and thunderstorms has developed just west of
I-35 this afternoon where the atmosphere has acquired some
weak/moderate instability. This activity has developed near a weak
mid-level impulse moving into western Missouri, but should
gradually weaken over the next few hours as it encounters a deeper
low-level stable layer over western and central Missouri.
Meanwhile the primary surface cold front is approaching the far
northwest tip of Missouri where a rather sharp temperature
gradient is separating mid/upper 80s over KS and MO from
mid/lower 60s across Nebraska. This boundary will slowly make its
way into northwest Missouri this evening and eventually reach the
I-35 corridor around 3 AM. The band of rain and storms that has
developed out ahead of the front is stabilizing the airmass over
KS and MO somewhat, but clearing and resulting destabilization
further west could still allow for a few stronger storms across
areas from near Topeka to just north of St Joseph later this
afternoon and this evening. Shear is rather weak so brief gusts to
50-60 mph and perhaps some marginally severe hail will be the
primary threats across these areas.

Storms may increase in coverage overnight as they push into
eastern KS and western/northern MO and become aided by a stronger
midlevel wave to the north, but with instability becoming
elevated they will likely lose some of their punch. Still, it
wouldn't be surprising to see some hail approaching an inch in a
few of the stronger storms through midnight or so, along with some
locally heavy rainfall. The front will become stalled just south
of US 50 on Sunday, and while a few storms are possible near this
boundary through the afternoon, the primary focus for additional
convection won't arrive until after dark Sunday evening when a
secondary mid-level impulse will move in from the southwest. Some
locally heavy rainfall is again possible with this activity
especially near the slowly retreating boundary, but the lack of a
strong low-level jet should keep the overall heavy rain/flash
flood threat on the low side. A series of weak upper-level
impulses will continue to stream into the area through Monday
evening keeping rain chances around through at least early
Tuesday.

Tuesday evening appears to be the most likely time to see a dry
period before another cold front brings another potential round of
storms to the area on Wednesday and into early Thursday.

&&

.Aviation...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1230 PM CDT SAT SEP 16 2017

Complex aviation forecast setting up for the next 18 to 24 hours.
Warm and humid airmass ahead of an advancing cold front is helping
to produce scattered showers and storms across northeastern KS and
northwestern MO. As the front moves southeast later this afternoon
and this evening, showers and storms should become a more
widespread. Have added a tempo group to try and capture the most
likely timing for storms into the terminals. In the wake of the
storms, showers or an area of rain is possible and as cooler air
moves in behind the front, ceilings will likely become low MVFR
and possibly IFR.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&

Discussion...Hawblitzel
Aviation...CDB

Hazardous Weather Outlook
National Weather Service Kansas City/Pleasant Hill MO
338 AM CDT Sat Sep 16 2017

KSZ025-057-060-102>105-MOZ001>008-011>017-020>025-028>033-037>040-
043>046-053-054-170845-
Atchison KS-Miami-Linn KS-Doniphan-Leavenworth-Wyandotte-Johnson KS-
Atchison MO-Nodaway-Worth-Gentry-Harrison-Mercer-Putnam-Schuyler-
Holt-Andrew-De Kalb-Daviess-Grundy-Sullivan-Adair-Buchanan-Clinton-
Caldwell-Livingston-Linn MO-Macon-Platte-Clay-Ray-Carroll-Chariton-
Randolph-Jackson-Lafayette-Saline-Howard-Cass-Johnson MO-Pettis-
Cooper-Bates-Henry-
338 AM CDT Sat Sep 16 2017

This hazardous weather outlook is for northwest...north central and
west central Missouri...as well as extreme eastern Kansas.

.DAY ONE...Today and Tonight

 A few strong to isolated severe storms will be possible this evening
 west of Interstate 35. The main threats will be for large hail and
 damaging winds.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

 Thunderstorms are expected Sunday however, severe weather is not
 anticipated.

 Another round of thunderstorms are expected Monday afternoon. A few
 strong to isolated severe storms will be possible.

 Several rounds of showers and thunderstorms will be possible during
 the upcoming work week. Flooding may become a concern.

 More detailed information can be accessed at...
 https://www.weather.gov/eax/hwo

Special Weather Statement
National Weather Service Kansas City/Pleasant Hill MO
345 PM CDT SAT SEP 16 2017

KSZ103-MOZ028-162115-
Leavenworth KS-Platte MO-
345 PM CDT SAT SEP 16 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN LEAVENWORTH AND
NORTHEASTERN PLATTE COUNTIES UNTIL 415 PM CDT...

At 345 PM CDT, Doppler radar was tracking a strong thunderstorm over
Leavenworth, moving northeast at 35 mph.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Leavenworth, Lansing, Platte City, Weston, Dearborn, Camden Point,
Tracy, Farley, Fort Leavenworth, Stillings, Beverly, Hoover and East
Leavenworth.

This includes the following highways...
 Interstate 29 between mile markers 14 and 30.
 Interstate 435 between mile markers 28 and 34.

LAT...LON 3953 9481 3953 9472 3939 9460 3935 9460
      3922 9500 3934 9510
TIME...MOT...LOC 2045Z 239DEG 32KT 3930 9496

Laflin

Special Weather Statement
National Weather Service Kansas City/Pleasant Hill MO
500 PM CDT SAT SEP 16 2017

MOZ014-015-022-023-031-162230-
Grundy MO-Carroll MO-Daviess MO-Livingston MO-Caldwell MO-
500 PM CDT SAT SEP 16 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN DAVIESS...GRUNDY...
NORTHWESTERN CARROLL...EASTERN CALDWELL AND LIVINGSTON COUNTIES UNTIL
530 PM CDT...

At 500 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Gallatin to Braymer. Movement was
northeast at 45 mph.

Dime size hail and winds in excess of 40 mph will be possible with
these storms.

Locations impacted include...
Chillicothe, Trenton, Braymer, Jamesport, Breckenridge, Wheeling,
Utica, Chula, Laredo, Ludlow, Mooresville, Tindall, Lock Springs,
Spring Hill and Dawn.

LAT...LON 3975 9338 3952 9377 3953 9387 3991 9394
      4027 9354 4026 9346
TIME...MOT...LOC 2200Z 225DEG 37KT 3988 9388 3958 9383

Laflin

Special Weather Statement
National Weather Service Kansas City/Pleasant Hill MO
539 PM CDT SAT SEP 16 2017

MOZ015-016-162330-
Grundy MO-Sullivan MO-
539 PM CDT SAT SEP 16 2017

...SIGNIFICANT WEATHER ADVISORY FOR EASTERN GRUNDY AND SULLIVAN
COUNTIES UNTIL 630 PM CDT...

At 539 PM CDT, Doppler radar was tracking a strong thunderstorm near
Galt, or 8 miles east of Trenton, moving northeast at 25 mph.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Milan, Browning, Spickard, Galt, Laredo, Humphreys, Pollock, Harris,
Osgood, Reger and Winigan.

LAT...LON 4004 9289 4003 9336 3999 9336 3997 9349
      4023 9363 4027 9354 4027 9337 4034 9337
      4039 9327 4039 9304
TIME...MOT...LOC 2239Z 244DEG 24KT 4007 9346

Laflin