Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 042329
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
529 PM CST Sun Dec 4 2016
Issued at 256 PM CST SUN DEC 4 2016
Fast-moving storm system that dropped as much as 2 inches of snow
across northern Missouri this morning is quickly clearing the area,
and skies should become mostly clear across the entire area shortly
after sunset. Winds will be quick to become southerly overnight,
and resulting moisture advection could favor some areas of fog
particularly over far northern Missouri where a little bit of snow is
still on the ground.
A closed upper low over Mexico will gradually kick out into the
Southern Plains on Monday, then become phased with the northern
stream over the Ohio Valley Monday night. Most of the precipitation
with this system will stay just to the east of the forecast area, and
anything that does make it this far west will be in the form of light
rain. The bigger story Monday night will be a strong cold front that
will surge through the area, keeping temperatures in the 30s and
lower 40s on Tuesday, then dropping well into the 20s Tuesday night.
The cold airmass that will settle into the region on Tuesday will set
the stage for light snow on Wednesday when another fast-moving upper
wave will track across the area. Despite the broad/weak structure of
the wave and its progressive nature, models all seem to agree that
enough deep lift and moisture will be in place so that light snow
accumulations appear increasingly likely during the day Wednesday.
Since this event will be mostly synoptically-driven, and since most
models are coming into decent alignment with each other, confidence
is a bit higher than average that many areas will see at least an
inch or two of snow. The most likely area for accumulating snow
appears to be near and south of the US 36 corridor although being 3
days out this most certainly could change. While it`s still a bit
early to look at details, there`s a decent signal suggestive of a
deep dendritic growth region and perhaps even some weak frontogenesis
that could lead to high liquid-to-snow ratios and a locally higher
snowfall rates. If true, then 3 to 4 inch amounts wouldn`t be out of
the question somewhere, but time will tell if and where such snow
amounts may be.
Behind Wednesday`s system Thursday is looking downright frigid. A
deep 1045 mb Arctic high settling into into the High Plains will
bring the coldest airmass our area has seen since January.
Temperatures will tumble into the lower teens and even single digits
both Wednesday night and Thursday night, while daytime highs on
Thursday will struggle to rise out of the teens in many areas.
Upper flow will become quasi-zonal by the end of this week into the
weekend. As would be expected in such a progressive pattern, models
are having a difficult time resolving any quick-moving systems that
may move across the area during this time. Therefore went ahead and
held onto precip chances over the weekend even though the most recent
runs of the GFS and ECMWF came in dry, since future runs could easily
revert back to a wetter solution.
.Aviation...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 529 PM CST SUN DEC 4 2016
Conditions should generally be VFR, with a few caveats. For the first
few hours of the forecast, a patch of low MVFR ceilings persists over
east central KS and west central MO. This appears to be thinning
out/dissipating based on fog channel imagery so have added a short
tempo group mentioning the low MVFR ceilings for a few hours. The
other issue is the potential for minor fog in the terminals. Recent
rain and temperatures cooling below the crossover temperatures
suggest at least some potential for fog. By tomorrow morning,
conditions should become VFR with light southerly winds.