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

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
000
FXUS63 KEAX 140330
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1030 PM CDT Sun Apr 13 2014

.UPDATE...
Issued at 1030 PM CDT SUN APR 13 2014

Not much has changed regarding snow chances overnight and early
Monday. Cold air is coming in a bit faster than previously thought,
with snow already being reported as far south as St. Joe. Current
activity is associated with deformation within an 800-hPa trough
axis, which will sag south toward I-70 through 06Z and then weaken as
it shifts more eastward into northern MO. Any precip through this time
will be very light and any snow will not accumulate. Updated
temperature forecasts bring the rain/snow line into northern parts of
KC near or shortly after midnight.

There should be a relative lull in precipitation later tonight before
the secondary batch of rain/snow which is currently entering SW KS
spreads into the forecast area near or shortly after 12Z. Most of
this precipitation should be snow when it arrives here, some of which
may produce some very minor accumulations. RAP/HRRR support the
ongoing forecast with a half inch or less accumulation mainly for the
KC metro and points south and west. This will mainly be on elevated
surfaces, and snow on roads shouldn`t be an issue given warm pavement
temps and air temperatures that should be in the lower 30s.

&&

.DISCUSSION...
Issued at 447 PM CDT SUN APR 13 2014

Overview...

Ongoing strong/severe weather associated with developing squall-line
is one of several weather concerns. In addition, a second upper
system further upstream will move through the Central/Southern
Plains later tonight/Monday and bring threat for some minor snow
accumulations. A third concern will be a hard freeze late Monday
night/Tuesday morning and a final forecast challenge will another
system which could bring not only rain on Thursday but it could mix
with snow Thursday night.

Tonight...

Developing squall-line from northwest MO into central OK is expected
to accelerate eastward this evening as an upper trough rotates
northeast through KS and enhances the upper level diffluence. Latest
HRRR and other short-range convective allowing models suggest this
line of strong/severe convection should exit the eastern CWA by 01z.
Combination of moderate instability and a nearly unidirectional
vertical wind profile will support this squall-line while the 0-3km
bulk shear of 25kt and clockwise hodograph in the lowest 1-2
kilometers will be able to support brief meso-circulations along
the squall-line. Damaging winds and large hail will be the primary
severe threats while precipitable water values nearing 3 standard
deviations above average and training of individual cells within the
southern flank of bowing segments will result in short duration but
very heavy rainfall.

Should see an hour or two of post-frontal stratiform rain and
embedded convection before the rain moves out. Wrap around
deformation zone rain is expected to lift northeast through northern
MO this evening while the southwestern CWA could be dry until late
tonight. Strong cold air advection could cool the column
sufficiently across northwest MO to allow for minor snow
accumulations late tonight. In addition, sub-freezing temperatures
are likely for several hours over far northwest MO and extreme
northeast KS.

Monday/Monday night...

A very raw and blustery day anticipated with snow now being
introduced. Temperatures will likely struggle to reach 40, which is
around 25 degrees below average.

Strong/gusty northerly winds will funnel very cold air in behind the
cold front which will spread through the CWA overnight. A second
deeper upper system will track east out of the Central Rockies
tonight and through KS/Southern Plains on Monday. The NAM has been
advertising accumulating snow for several days and the last couple
runs of the GFS and ECWMF have jumped on the bandwagon. We`ve been
trending colder for the past couple of days and the column looks to
be cold enough now to support minor snow accumulations for west
central MO and adjacent east central KS during the morning hours.
Believe temperatures will warmer enough by afternoon to change to a
rain/snow mix.

Passage of the upper trough Monday night will result in strong
sinking motion and clearing as a surface ridge moves in. A hard
freeze with overnight lows in the mid to upper 20s will require
another headline, possibly being issued during the midnight shift.

Tuesday/Wednesday...

A rather quick transition from northwest to nearly zonal flow will
allow for a modest warm-up with highs reaching the lower 60s by
Wednesday.

Thursday-Sunday...

The next storm system will likely move into the central U.S. by
Thursday. There is considerable differences between the GFS and
ECMWF solutions with the GFS depicting an anomalous deep and closed
upper system. GFS solution suggests potential for minor snow
accumulations. However, due to the degree of uncertainty will not
mention any accumulation but go with a rain/snow mix.

Next Weekend...

Low amplitude upper ridging moves in for Saturday drying things out
but both the ECMWF and GFS spread warm air advection precipitation
into the region. For now will use low PoPs.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 630 PM CDT SUN APR 13 2014

Line of strong storms will make steady progress into northeast and
central MO this evening with strong winds possible for IRK and DMO.
Behind this line, light rain is tapering off across the KC and STJ
areas where ceilings have dipped into IFR at spots. These ceilings
should rise above 1000 feet over the next couple of hours as winds
increase from the northwest. Could see a few light showers
redeveloping later tonight but these should be of minimal impact.
Still looks like an area of light snow will develop over southern KS
later tonight and spread into western MO later Mon morning. Ground
temps will be warm but this could still result in very light
accumulations under an inch.


&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...FREEZE WARNING from 4 AM to 10 AM CDT Monday FOR KSZ025-102.

MO...FREEZE WARNING from 4 AM to 10 AM CDT Monday FOR MOZ001>003-011-
     012.

&&

$$

UPDATE...Hawblitzel
DISCUSSION...MJ
AVIATION...Hawblitzel






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.