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

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FXUS63 KEAX 141117

517 AM CST Sun Dec 14 2014

Issued at 318 AM CST SUN DEC 14 2014

Water vapor imagery clearly shows the amplified flow across the
CONUS with the storm system that will affect our area later
today/tonight over the southern Rockies. Persistent southerly flow
ahead of this system is advecting copious amounts of moisture for
this time of year, as well as very warm temperatures into the area.
Temperatures again look to possibly reach and/or exceed 60 degrees
early this afternoon. Timing of the rainfall looks to be late this
afternoon/early this evening across eastern Kansas and extreme
western Missouri. This area will then spread eastward overnight. Models
continue to show small amounts of instability with this system so it
still looks possible that we`ll see embedded thunderstorms within the
whole rain area. By Monday afternoon, the system becomes vertically
stacked over northern Missouri. Relatively steep low-level lapse
rates and a skinny CAPE profile suggest convection will persist into
the afternoon. With well defined surface boundaries and a low LCL
there may be some potential for vertically stretching those
boundaries. Would not be surprised to see some funnel cloud reports
Monday afternoon. But this will really depend on how much
instability is present and at the moment would not anticipate
anything severe out of this.

This system will move away by Tuesday, leaving cold air in its
place. This will help to set the stage for the next round of
precipitation Wednesday night into Thursday. Model consistency is
not very good for the mid-week system but they do show a band of
moisture lifting northward. Forecast soundings show the entire column
below freezing with a high likelihood of ice crystals being present.
This indicates that snowfall may spread northward across mainly the
southern half of the forecast area Wednesday night through Thursday.
Models then show another wave moving out of the southern Rockies late
in the week. Timing remains a challenge and the GFS and the ECMWF vary
greatly on how far south the wave will actually move, with the ECMWF
being very far to the south. The GFS, on the other hand, depicts a
scenario that is favorable for measurable snowfall Friday into
Saturday. There is still plenty of time to monitor this system but
for now there is an increasing potential for measurable snowfall late
in the week.


.AVIATION...(For the 12Z TAFS through 12Z Monday Morning)
Issued at 517 AM CST SUN DEC 14 2014

Low MVFR ceilings will likely persist through much of the morning and
possible into the afternoon. At some point this afternoon conditions
may improve with ceilings at or above 2500 ft expected. The timing of
this is uncertain though. But think with deeper mixing cloud bases
will rise ahead of the line of rainfall expected to move in the later
half of the forecast. Timing of that rain looks to be around 03Z at
the terminals. Ceilings will also likely drop to low MVFR or IFR and
visibility will be restricted as well. By the last few hours of the
forecast the main area of rainfall should have pushed east with
residual light rain continuing. With the heavier rain having pushed
east ceilings may once again lift to the higher end of MVFR or even
VFR. But visibility should remain MVFR and some guidance suggest IFR
visibility, but will let later shifts evaluate that possibility closer
as confidence is already low that far out.




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