Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 141725
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1125 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 18Z TAFS through 18Z Monday Afternoon)
Issued at 1125 AM CST SUN DEC 14 2014
Low stratus prevailing at area terminals early this afternoon.
Latest model trends suggest the combination of mixing and daytime
heating may be enough to allow CIGS to rise above MVFR thresholds
later this afternoon. For now...have advertised this possibility with
a TEMPO at all sites with the exception of IXD who looks to be more
socked in due to farther westward position. Beyond this
afternoon...focus continues to be on impending rain for all terminals
after the 2-3Z time frame. Cannot rule out temporary restrictions
below IFR but will allow later forecasts the opportunity to get a
little more specific once upstream trends are established. Rain
chances to continue through the night with slight improvements likely
towards the end of the fcst period.