579 
FXUS63 KEAX 221703
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1203 PM CDT Wed Apr 22 2015

.DISCUSSION...
Issued at 347 AM CDT WED APR 22 2015

For today, cooler temperatures are expected in the wake of a cold 
front which passed through the region late last evening. Highs may 
struggle to reach 60 degrees; however, diminishing north winds and 
sunshine should help take the edge off the below normal temperatures 
in all but far northeastern portions of the CWA. Patchy frost is 
possible again tonight as surface high pressure builds into the 
region, especially across far northern and northeast MO where nearly 
calm winds are expected by daybreak and temperatures will be coldest 
aloft.

Quiet conditions will continue into Thursday, when temperatures 
should begin to warm under light but veering surface winds and zonal 
flow aloft. The main focus; however, will be Friday and Friday night 
when a shortwave trough lifts out of the four corners region and 
into the central Plains, and a resultant surface low kicks out into 
central KS.

Widely scattered, elevated storms are expected to develop ahead of 
the deepening surface low by midday Friday, limiting the potential 
instability that can develop by Friday afternoon and evening when 
the surface warm front begins to lift into central KS and west 
central MO. However, the potential for storms to develop along the 
warm front is still high due to very strong synoptic-scale dynamics 
associated with the shortwave trough and upper jet. MUCAPE values 
during the late afternoon and evening are generally 500 J/kg or less 
in our CWA, but will be coincident with 0-3 km helicity values of 
400-500+ m2/s2 near the warm front, spelling a fairly classic high 
shear/low CAPE setup for areas near the boundary. Low-topped 
supercells are possible from late afternoon through the overnight 
and early morning hours, due to continued strong dynamics and the 
likelihood of the boundary layer remaining mixed overnight.

Areas that see strong to severe storms will be almost entirely 
dependent on how far north the warm front can lift Friday evening, 
especially since morning/early afternoon convection should not 
significantly impact the potential for storms later in the day. 
Model solutions still differ on the position of the surface low, and 
to a lesser degree its timing, but both the NAM and GFS bring the 
warm front up to the KC metro area prior to 06z Saturday, and the 
EC's more southern track is not significantly different, bringing 
the front just south of the metro before lifting it out to the east. 
Areas north of the warm front could see isolated, elevated strong to 
severe storms during the evening and overnight hours, but the threat 
will be considerably less as the environment quickly becomes less 
supportive south to north. Heavy rain may also be a concern with 
this system in areas that see several rounds of storms both in the 
morning and again along the boundary, especially if cells begin to 
train along the front.

Showers will likely wrap in behind the surface low on Saturday, but 
whether or not those impact the majority of the CWA will depend on 
how the surface low exits the region -- a more northeasterly track 
would keep the majority of the area dry on Saturday, while the more 
southern EC solution drags rain showers through the entirely of the 
forecast area. Otherwise, seasonable temperatures and a few quick 
shots of light showers or isolated storms are expected through the 
remainder of the long-range forecast.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1202 PM CDT WED APR 22 2015

A weak high pressure over the area will keep the region under VFR
conditions with light winds. Scattered to perhaps broken mid/high
level clouds are expected to move into the area tonight but will not
have any impact on aviation.

&&

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

$$

DISCUSSION...Laflin
AVIATION...CDB