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Area Forecast Discussion (AFD)

Issued by Kansas City/Pleasant Hill, MO (EAX)

                            
000
FXUS63 KEAX 191130
AFDEAX

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
530 AM CST Tue Feb 19 2019

.Discussion...
Issued at 316 AM CST TUE FEB 19 2019

Bottom line: Forecast remains largely unchanged as confidence 
remains high for accumulating snowfall later today into tonight. A 
Winter Storm Warning has been issued for far northwest Missouri, 
with a Winter Weather Advisory for all other areas. 

Upper wave over the Desert Southwest will quickly eject into the 
Plains states later today, becoming increasingly negatively-tilted
and drawing moisture northward. Biggest forecast challenge 
remains on timing of mid-level dry slot that gradually erodes 
cloud ice and transitions snowfall production to light freezing 
rain/drizzle. As it stands, greatest deep ascent and saturation 
should occur prior to midnight, with a loss of cloud ice 
following. With initial dry air to overcome, there remains some 
model spread with respect to the timing of precipitation 
reaching/developing over the forecast area. Most probable period 
will be late afternoon to early evening across the area, with a 
rapid spread/increase in precip rates thereafter. The most likely
period for accumulating snowfall is expected between 00-07Z, with
a transition to lighter precipitation in the form of light 
freezing rain/drizzle or a mix thereafter. All accumulating 
precipitation is expected to conclude before/around sunrise 
Wednesday. Snowfall amounts will be highest in far NW MO with 
totals in the 5-7" range where persistent, deep lift/saturation 
will reside. Points south and east can expect a steady reduction 
in amounts, with 3-4" from KC to Kirksville. For areas of east 
central Kansas to central Missouri, snowfall amounts of 1-3" are 
possible, along with total ice amounts up to 0.10". Biggest period
of impacts with active weather is anticipated between 00-08z, 
with moderate snowfall rates that will quickly accumulate and 
greatly reduce visibilities will little visual cue - followed by 
light icing that may further cause hazardous conditions. Travel 
across the entire forecast area is expected to become 
difficult/hazardous beginning this evening into Wednesday morning.

The system will quickly lift to the north in response to another 
strong wave diving southeast along the California Coast - our next 
notable weather maker. Due to this, minimal cold air advection is 
expected and temperatures will moderate Wednesday into Saturday, 
with even some areas returning to the 50s by the end of the week. 
Model spread has improved and confidence is increasing for this next 
strong wave to through on Saturday. The track will be critical to 
determining precipitation type, but currently the majority of the 
precipitation looks to be in the form of rain. In fact, moisture and 
instability will be on the increase ahead of the system, and a few 
thunderstorms are certainly possible with the dynamics and 
environment in place. On the backside, cannot rule out wrap-around
minor snow accumulations in NW MO as the system departs.

&&

.Aviation...(For the 12Z TAFS through 12Z Wednesday Morning)
Issued at 527 AM CST TUE FEB 19 2019

Current VFR conditions will eventually give way to deteriorating
conditions by early this evening as snowfall moves into terminal
space. Notable reductions in vis/cig expected. Conditions 
gradually improve prior to sunrise Wednesday.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...Winter Weather Advisory from 4 PM this afternoon to 9 AM CST 
     Wednesday for KSZ025-057-060-103>105.

     Winter Weather Advisory from 6 PM this evening to 9 AM CST 
     Wednesday for KSZ102.

MO...Winter Weather Advisory from 4 PM this afternoon to 9 AM CST 
     Wednesday for MOZ028>033-037>040-043>046-053-054.

     Winter Weather Advisory from 6 PM this evening to 9 AM CST 
     Wednesday for MOZ007-008-012>017-020>025.

     Winter Storm Warning from 6 PM this evening to 9 AM CST 
     Wednesday for MOZ001>006-011.

&&

$$

Discussion...Blair
Aviation...Blair