Severe Thunderstorm Warning 261, NWS Kansas City, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
422 AM CDT THU SEP 10 2015

.DISCUSSION...
Issued at 421 AM CDT THU SEP 10 2015

Today - Tonight...

In the very short term the remnants of a long-lived mini-complex of
thunderstorms looks like it will have enough legs to push into the
far western CWA before dissipating after sunrise. Feature is being
powered by a shortwave trough tracking east through the base of a
broad upper level trough covering the north central states down into
the Mid MO Valley. Moist isentropic ascent on the 305K and 310K
surfaces feeding/lifting marginal instability into this complex will
maintain activity for several more hours.

Remainder of the day will be spent waiting for the development of
strong/severe convection over KS/MO. A moderately strong cold front
will drop southward from SD/MN and encounter a moderately unstable
airmass residing over KS and MO where operational models show
MLCAPES in excess of 2000J/kg this afternoon. Favorable
0-6km shear of 40kts will provide a favorable environment for
rotating supercells which will support the production of large hail
for the first few hours before the convection evolves into short
line segments and mini-bows which will then favor damaging winds.
Agree with the area depicted by the latest SPC Day 1 outlook which
places a slight risk of severe storms over west central MO and
adjacent east central KS. One caveat is if any residual boundaries
will linger from this mornings storms which would certainly muddy up
the waters.

With very good agreement between models on timing and location have
sufficient confidence to increase PoPs over the western CWA for
late afternoon into the evening hours. And with precipitable water
values increasing to near 2 inches and favorable timing of
convection heavy rains are likely. With steering flow in excess of
30kts believe storm motion will be fast enough that cells won't
reside long enough to warrant a flash flood watch.

Model trend is a bit faster so have ended rains a bit faster tonight.

Friday - Tuesday...

A dry and very pleasant period with much below average temperatures
starting off and then then a gradual warm-up back to normal.

The upper trough is expected to sharpen early in the period allowing
a surge of very cool and dry air to overspread the region and
resulting in fall-like temperatures. Will see morning lows dip into
the 40s Saturday and Sunday with afternoon highs in the upper 60s-
lower 70s through Sunday.

Warm air advection commences for the start of next week as the upper
trough pushes eastward allowing heights to rise and warmer air
parked over the Southern Rockies advects northeastward.

Wednesday...

The ECMWF and GFS are similar in lowering heights east of the
Rockies in advance of a sharp shortwave trough ejecting northeast
through the Rockies. Rain chances likely to increase but questions
revolve around the placement of the cold front.

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1159 PM CDT WED SEP 9 2015

VFR conds will prevail thru tomorrow afternoon with mid-lvl clouds
expected through late morning. By late morning sct cu around 4kft
will be thr rule. Winds will be light and vrb overnight before
picking up out of the SW around 5kts during the morning hours. A cold
front will approach the terminals this evening with thunderstorms
developing around the terminals around 21Z-23Z. Storms will contain
heavy rain which will reduce vsbys to 3-5SM. Storms will cont thru
the remainder of the TAF period at all but STJ when -tsra should come
to an end around 03Z. Winds will shift to the north btn 5-10kts
behind the front.

&&

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

DISCUSSION...MJ
AVIATION...73

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
413 PM CDT WED SEP 9 2015

KSZ025-057-060-102>105-MOZ001>008-011>017-020>025-028>033-037>040-
043>046-053-054-102115-
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-
413 PM CDT WED SEP 9 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHWEST...NORTH CENTRAL AND
WEST CENTRAL MISSOURI...AS WELL AS EXTREME EASTERN KANSAS.

.DAY ONE...TONIGHT

 STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE ACROSS NORTHWEST
 MISSOURI AND NORTHEAST KANSAS THURSDAY AFTERNOON AND EVENING. LARGE
 HAIL WILL BE THE BIGGEST THREAT...HOWEVER ISOLATED STRONG WIND
 GUSTS CANNOT BE RULED OUT. IN ADDITION...HEAVY RAIN MAY LEAD TO
 LOCALIZED FLASH FLOODING AS STORMS CONTINUE THROUGH THE OVERNIGHT
 HOURS.

 MORE DETAILED INFORMATION CAN BE ACCESSED AT...
 HTTP://WWW.WEATHER.GOV/EAX/HWO

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

 NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

 MORE DETAILED INFORMATION CAN BE ACCESSED AT...
 HTTP://WWW.WEATHER.GOV/EAX/HWO

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
429 AM CDT THU SEP 10 2015

KSZ103-105-101015-
JOHNSON KS-LEAVENWORTH KS-
429 AM CDT THU SEP 10 2015

...SIGNIFICANT WEATHER ADVISORY FOR LEAVENWORTH AND NORTHWESTERN
JOHNSON COUNTIES UNTIL 515 AM CDT...

AT 428 AM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR
OSKALOOSA...MOVING EAST AT 40 MPH.

HALF INCH HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THIS STORM.

LOCATIONS IMPACTED INCLUDE...
OLATHE...GARDNER...LANSING...BONNER SPRINGS...DE SOTO...TONGANOXIE...
BASEHOR...LINWOOD...RENO...FAIRMOUNT...CLEARVIEW CITY AND JARBALO.

THIS INCLUDES KANSAS TURNPIKE BETWEEN MILE MARKERS 206 AND 222.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 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 AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
OFFICE IN PLEASANT HILL.

&&

LAT...LON 3931 9517 3922 9486 3920 9487 3920 9490
      3882 9492 3886 9506 3898 9506 3899 9507
      3898 9509 3896 9508 3898 9516 3896 9517
      3897 9519
TIME...MOT...LOC 0928Z 291DEG 34KT 3916 9533

LG