000
FXUS63 KEAX 170349
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1049 PM CDT Thu May 16 2013

.SHORT TERM...(This Evening through Friday)
Issued at 321 PM CDT THU MAY 16 2013

The short term forecast remains quiet despite several upper level
features across the region. Water vapor imagery shows a large upper
level low continues to circulate across northern Arkansas and
southern Missouri. Meanwhile, a compact shortwave continues to cross
western Nebraska this afternoon, driving convection over NW Kansas
and north central Nebraska to the east. At the surface, a stationary
boundary continues to stretch from west to east over northern
Nebraska through south central Iowa. lingering morning convection and
cloud cover has reinforced a weak outflow boundary into northern
Missouri.

This afternoon and tonight:  Widely scattered showers and
thunderstorms will continue over northern Missouri along this
stalled boundary, despite rather weak convergence. Further south, an
18Z aircraft sounding from KMCI indicated a tall and thin CAPE layer
with minor capping around 700 mb.  Given the weak influence of the
lingering upper low to the south and poor shear, a few widely
scattered showers or thunderstorms will continue to be possible into
the evening. Higher POPs will be confined to the eastern portions of
Missouri along I-70 where stronger surface convergence is focused.
This diurnal based activity will dissipate quickly this evening, with
activity further west over Nebraska/Kansas also expected to diminish
as it arrives.

Significant boundary layer moisture advection combined with light
winds should result in the development of stratus/fog after
midnight.

Friday:  Clouds will quickly clear in the morning allowing
temperatures to climb into the lower or even middle 80s.

.LONG TERM...(Friday Night through Thursday)
Issued at 321 PM CDT THU MAY 16 2013

Upper pattern will become more amplified on Saturday as a
significant upper trough digs across the Rockies. Downstream ridging
across the Plains/Mississippi Valley will provide generally dry and
warm conditions on Saturday. With 850 hPa temps rising into the low
20s and good mixing, daytime temps should have no problem rising
into the middle or even upper 80s. Capping inversion overhead should
keep any threat for convection to the west and northwest of the
forecast area through Saturday night. Most models are producing
scattered elevated convection across MO and ern KS Saturday night in
response to weak impulses ahead of the advancing longwave trough.
However, elevated CIN appears fairly significant so kept Saturday
night dry for now.

An active period is in store for Sunday and Monday as the longwave
trough to the west slowly advances eastward and interacts with an
unstable airmass over the Plains. Several pieces of energy rotating
around the base of the trough will result in multiple waves of
thunderstorms Sunday through Monday night. Several days of
trajectories off the Gulf will allow dewpoints to rise well into the
60s, although models remain too aggressive with boundary layer
moisture bringing dewpoints into the 70s. Still, instability will
likely be moderate to strong both Sunday and Monday depending on the
amount of remnant clouds and precip. Meanwhile increasing mid-level
flow will be more than supportive of severe storms both days.
Closest analogs for both Sunday and Monday all point to major severe
weather/tornado outbreaks from the past, notably Apr 26 1991
(Andover KS) and the Memorial Day weekend outbreak of 2004. Thus the
upcoming weather for early next week will need to be monitored
closely.  Still, a lot hinges on details that can`t be pinpointed at
this time, particularly the degree to which instability and overall
severe potential is affected by lingering clouds and precip. Flooding
will also be a concern particularly Monday and Monday night.

Thunderstorm chances will gradually decrease by Tuesday as the upper
trough quickly weakens and becomes absorbed into ridging over the
Canadian Plains. Upper flow will then become quasi-zonal through
Thursday with near-average temperatures and low chances for
thunderstorms Weds night and Thurs as weak impulses track overhead.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1048 PM CDT THU MAY 16 2013

Only issues for the terminals over the next 24 hours will be this
morning as nearly clear skies might allow for the development of
light fog in the morning. However, confidence is low owing to the
amount of dry air in place across the region.

&&

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

$$

SHORT TERM...31
LONG TERM...Hawblitzel
AVIATION...Cutter