687 
FXUS63 KEAX 050915
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
315 AM CST Mon Feb 5 2018

.Discussion...
Issued at 314 AM CST MON FEB 5 2018

Our surprise snow cover from today over most of the CWA combined with 
clear skies and light winds due to high pressure has resulted in 
very cold low temperatures near zero. As the high shifts to the east 
the return southerly flow may help increase these temperatures 
slightly near sunrise and then quickly pushing up into the upper 20s 
throughout the day. Wind chill values in the morning will mostly be 
below zero through the mid morning with close to -10F along the 
IA/MO border. A shortwave trough over western Nebraska will shift to 
the ESE and effect northern Missouri this afternoon. The majority of 
the isentropic lift will luckily stay north of the Iowa border, but 
the southern end of this system is expected to drop between 1-2" of 
snow across our NE CWA region with a dusting to 1" as far south as 
the Missouri River.  Cold air will advect back into the area with N-
NE winds overnight as temps drop down into the single digits over 
our northern CWA and teens to the south.  This stable wave and 
associated cold front will also stack back to a mid level baroclinic 
boundary that will set up in central Kansas which will be vital to 
the snow forecast going into Tuesday.  

A new shortwave moving into the southern Rockies Tuesday morning 
will shift the mid level winds to the SW on the downstream side, 
intensifying the frontogenesis along that stalled low to mid level 
boundary over central Kansas. As this shortwave progresses to the 
east the winds will increase which will intensify the frontogenesis 
from 800-600mb near the I-70 corridor.  There is still quite a bit 
of model spread on where the forcing will be for QPF development, 
but the overall similarities between the GFS/ECMWF/Canadian all have 
this boundary in a similar position. The NAM continues to be the 
outlier in this scenario as it moves this boundary to the north 
quickly and is much drier in the lower levels than the other models. 
Due to this model being the main outlier to the others is has been 
given much less weight in this forecast. The model that has been the 
most consistent with this mid level frontogenetic boundary has been 
the GFS, so more weight was given to that model in the QPF forecast. 
Examining the GEFS ensemble plumes for Kansas City reveals the 
operational GFS is right near the mean of around 0.15-0.20" for our 
area.  The spread in the model perturbations was 0.05 to 0.3" so 
that middle ground with the majority of the plumes in that region 
seemed like the best way to go at this point.  The ECMWF does want 
to put more QPF north of the Missouri River than to the south so 
this spread between the GFS and ECMWF will need to be watched as it 
could have drastic implications if one starts to look more realistic 
than the other.  GFS profiles near St. Joseph also look to have some 
elevated MUCAPE which could result in possible mesoscale banding 
forming up somewhere between the MO River and St. Joseph which would 
lead to localized higher totals.  There is still to much uncertainty 
in placement to try to nail this area down so for now the forecast 
is looking for a broad area of 2-3" across the KC Metro and east 
down the Missouri River valley. There is slightly less confidence 
south of the Missouri River due to the spread in QPF solutions 
between the GFS and ECMWF, but since this forecast leans more 
towards GFS it still has at least over 1-2" all the way to our 
southern CWA border. Due to this uncertainty south of the Missouri 
River any headlines for this storm will most likely be issued during 
the day today in hopes the models can start to come more into 
agreement on placement of QPF with subsequent model runs. 

Higher pressure and cold temperatures will once again filter into 
our area Wednesday morning with low temps in the single digits to 
teens.  Snow cover and a northerly wind flow will keep high 
temperatures below freezing for Wednesday. As the high pressure 
moves east the southerly wind flow will help warm things up Thursday 
into the mid 40s.  Friday the long wave pattern will shift south as 
an incoming shortwave trough moves into the NW US. There is some 
model discrepancies on whether there will be enough lift for snow or 
not over northern Missouri so PoPs have been kept at a chance for 
now. This incoming trough looks to make things interesting going 
into next weekend as the GFS spins up a low over OK that could set 
up to another winter weather scenario, but this far out it will 
remain just a chance in the forecast for precip until we get close 
to the event.  

&&

.Aviation...(For the 06Z TAFS through 06Z Monday Night)
Issued at 1142 PM CST SUN FEB 4 2018

VFR conditions are expected for the period for everyone except
those in northeast MO, including Kirksville. Another shortwave
trough is forecast to move through tomorrow and should produce
some light snow in northeast MO. This will also drop ceilings 
into the MVFR category and visibility in the IFR category. There 
is a chance for areas as far west as STJ to see some snow in the 
afternoon, but confidence is low at this time. Everywhere else 
should be dry and see ceilings become low-end VFR. The system is 
expected to move out of the area shortly after sunset, taking the 
snow and low ceilings and visibilities with it. Therefore, VFR 
conditions are expected for the entire forecast area for the last 
quarter of the TAF. As for winds, right now a surface high is 
moving over the area making them light and variable. As the high 
pushes south and east, they will shift to the south. For a few 
hours tomorrow afternoon, winds will increase and may becomes a 
little gusty. Tomorrow evening, another cold front will push 
through, shifting winds back to the northwest.


&&

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

$$

Discussion...Barham
Aviation...Grana