Special Weather Statement, NWS Kansas City, MO

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
311 PM CDT Thu Aug 10 2017

.Discussion...
Issued at 310 PM CDT THU AUG 10 2017

A cold front is moving into far northwestern MO early this afternoon
and will continue to move southward through the evening and overnight
hours. This front may become a focus for showers and storms late
this afternoon into the overnight hours. But there are a few items
that are contributing a good amount of uncertainty. First, the
convection over western KS is spreading cirrus eastward and will
likely envelope the forecast area this afternoon and this evening.
In parts of eastern KS, where the cirrus has move into already, a
noticeable decrease in the diurnal CU has occurred before the cirrus
becomes too thick to see through. This adds some uncertainty to just
how much instability will be available for any convection in our
area. Second, there is very weak surface and low level flow ahead of
the front. Thus, convergence along the front is weak and this leads
to uncertainty regarding the initiation and coverage of possible
storms.

With all that said, scattered convection should develop along the
front late this afternoon in northern MO. Models suggest there may
be as much as 2000 to 3000 J/kg of CAPE in the area with 30 to 40
kts of 0-6km shear. Forecast soundings show a CAPE profile that's
not quite as robust with perhaps up to 2000 J/kg and weaker shear
confined to mainly the 3-6km layer. Forecast soundings also show a
shallow inverted V due to mixing to only about 3500 to 4000 feet.
All this suggest that the storms that do develop may be marginally
strong across northern MO and mainly a strong wind/downburst threat.
Small hail will be possible with initial updrafts but the overall
threat should become strong winds as the front pushes everything
southward through the night.

The front should push south of the forecast area by tomorrow morning
with any lingering precipitation confined to our far southern zones
through the middle of the day Friday. With drier air moving in
behind the front it should be relatively comfortable day with highs
in the low to mid 80s and middle 60 degree dewpoints. Relatively
pleasant conditions will persist into Saturday with similar
temperatures and cooler dewpoints. For Sunday, there may be more
widespread showers and storms across parts of KS with some of this
activity spreading east into our forecast area. At the very least,
thicker cloud cover looks likely which will help keep temperatures
well below normal. For now it looks like highs may only be in the
70s across the area. The cooler pattern looks to persist at least
through the middle of the week with highs 5 to 10 degrees below
normal.

&&

.Aviation...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1228 PM CDT THU AUG 10 2017

Initial afternoon CU development is in the MVFR range but should
lift to low VFR around 3000 to 3500 feet later this afternoon. A
cold front moving into the area this evening will lead to showers
and few storms. At the moment, it does not look like solid line of
storms will move through the area. So have just mentioned VCTS
at this point as the coverage doesn't justify blocking multiple
hours with a TSRA group. But timing for this activity will be from
01Z through 06Z as the front pushes through from the north. VFR
conditions are expected in the wake of the front with winds
turning to the north.

&&

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

Discussion...CDB
Aviation...CDB

Hazardous Weather Outlook
National Weather Service Kansas City/Pleasant Hill MO
528 AM CDT Thu Aug 10 2017

KSZ025-057-060-102>105-MOZ001>008-011>017-020>025-028>033-037>040-
043>046-053-054-111030-
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-
528 AM CDT Thu Aug 10 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

Isolated thunderstorms are possible this morning across the area,
with another round of thunderstorms this afternoon and evening. A few
strong storms will be possible will be possible this afternoon and
evening.

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

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

Off and on storm chances will resume by the late week and into the
weekend. No severe weather or flash flooding is expected.

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

Special Weather Statement
National Weather Service Kansas City/Pleasant Hill MO
539 PM CDT THU AUG 10 2017

KSZ102-102330-
Doniphan KS-
539 PM CDT THU AUG 10 2017

...SIGNIFICANT WEATHER ADVISORY FOR DONIPHAN COUNTY UNTIL 630 PM
CDT...

At 538 PM CDT, Doppler radar was tracking a strong thunderstorm near
Denton, or near Highland, moving southeast at 5 mph.

Half inch hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Wathena, Highland, Troy, Denton, Doniphan, Severance, Leona, Fanning
and Bendena.

LAT...LON 3981 9534 3989 9529 3989 9514 3986 9509
      3987 9503 3985 9494 3978 9494 3973 9497
      3969 9497 3967 9502 3962 9506 3962 9510
      3965 9512 3965 9534
TIME...MOT...LOC 2238Z 312DEG 6KT 3979 9529

CDB