Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO

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000
FXUS63 KEAX 240413
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1113 PM CDT Sat May 23 2015

.DISCUSSION...
Issued at 330 PM CDT SAT MAY 23 2015

Initial warm air advection shwrs/iso storms now developing across far
southwestern portions of our CWA this afternoon...all in advance of
main warn front which still resides down across the Southern Plains.
To our west...all eyes on a line of convection which has been in
place much of the morning and now extends from near Topeka south
into central Oklahoma and the Panhandle of Texas. Speed/distance tool
would suggest this activity to work into the greater KC area shortly
after 7 PM if initial movement and speed are maintained. Once it does
move in...a prolonged period of light to moderate rainfall is
expected...with additional energy expected to arrive overnight as
an MCV from the west Texas/southwest Oklahoma activity tracks north
with time. As has been highlighted in recent days...atmospheric
moisture content remains very high (PWATs 2-3 standard deviations
above normal) and a strengthening low-level jet overnight will lead
to increased moisture convergence across the lower Missouri
Vly...especially from 6z onwards. The end result will likely be
rainfall totals in the 1-2" range across portions of the area by 12z
Sunday (especially west of Route 65). Latest forecast soundings for
the area show a few hundred joules of elevated CAPE overnight which
should support weak convection as activity intensifies. Convective
rainfall rates combined with anomalously high atmospheric moisture
should lead to efficient rainfall production as warm cloud layer
depths remain in excess of 10kft. See absolutely no reason to change
the flash flood watch at this point...and later shifts may need to
consider expanding once trends become better established with
current/future convection.

No real change to the line of thinking for Sunday as the day looks
very wet and unsettled. Initial round of moderate to locally heavy
rains should be pulling off to our north Sunday morning...however
latest NAM and GFS models continue to show redeveloping shwrs/storms
by early afternoon across the western CWA as a weak sfc and 850-hPa
low center track north along a density discontinuity in place along
the Missouri/Kansas border. Additionally...next upstream shortwave
expected to approach the area during the afternoon hrs as main
western U.S. trough ejects into the central High Plains. With no
change in airmass expected...rainfall tomorrow should remain highly
efficient which combined with slightly better instability...will
support a continued flood threat through the day and evening hours.
If this develops as advertised...its conceivable to see another inch
along and west of Route 65...with lower amounts further east. Based
on everything listed above...main concerns remain focused on area
rivers and streams as many still remain high due to heavy rains last
week.

Light at the end of the tunnel finally begins to show itself late
Sunday night/early Monday as previously mentioned sfc low and
shortwave track north into the upper Mississippi Vly. While region
will reside solidly in the warm sector with no cold frontal
passage...latest model trends would suggest high atmospheric moisture
content will be scoured out to some degree following the passage of
said features Sunday night. Despite this...shwrs/storms look
possible by Monday afternoon especially across northwest
Missouri/northeast Kansas as next upstream upper wave approaches.
With a fair amount of instability in place...cannot rule out a few
strong/severe storms as better wind fields move in aloft.

Beyond this...much of next week continues to look unsettled with
repeated rounds for shwrs/storms just about each day. Main cold front
associated with western U.S. trough expected to approach the area
Tuesday night...and stall across the northern CWA by early Wednesday.
This feature will act as a focusing mechanism for renewed convection
before main feature passes later the week/early next weekend. If
there/s any silver lining to be had from what appears to be non-
stopped rain chances through next week...at least the grass will
stay green...

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1113 PM CDT SAT MAY 23 2015

Moderate rain will continue to spread north northeast through at
least 12z at all TAF sites. Visibilities will be generally MVFR, but
could occasionally drop to IFR in periods of heavy rain. Ceilings
will progressively lower over the next few hours, likely lowering
into the IFR category by 09z. Rain will eventually push off to the
east but may not clear up entirely, possibly leaving a few very
isolated light showers for the remainder of Sunday. Surface winds
should remain 10-12 kts and prevent low-level wind shear concerns,
but winds at 2-3 kft will increase sharply to 40-50 kts over the
next few hours from the south southwest.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH through Monday morning FOR KSZ025-057-060-
     102>105.

MO...FLASH FLOOD WATCH through Monday morning FOR MOZ012>014-020>023-
     028>033-037>040-043>046-053-054.

&&

$$

DISCUSSION...32
AVIATION...Laflin






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