Scientific Forecaster Discussion
fxus63 keax 161057
Area forecast discussion
National Weather Service Kansas City/Pleasant Hill MO
557 am CDT Mon Jul 16 2018
issued at 401 am CDT Monday Jul 16 2018
Primary forecast focus is on rain chances Wednesday through Thursday.
This morning, some patchy fog remains likely, especially along the
river valleys and low lying areas, but overall, temperature/dew
point spreads are wider at most sites, so do not anticipate any
greater spread of fog this morning.
An area of convection continues to persist over central Kansas. This
is rooted along a weak baroclinic zone nestled between the strong
500mb trough centered over the Great Lakes and the ridge built over
The Four Corners and intermountain west. One could make the
argument, this focusing is a very weak, diffuse, surface boundary.
Given latest radar trends it appears this area of convection will
persist through dawn, gradually building east and southeast. Latest
cams (convective allowing models) come to a similar conclusion, so
we've got that going for US. With that all said, the bulk of
convection today looks to remain south of the kc Metro, as little
movement is expected along the surface boundary given the lack of
support aloft. The most movement will likely be a slow southward
shift of the boundary through tonight. With MLCAPE values focused
along the weak boundary of 800 to 1200 j/kg, scattered convection
will likely be on tap from central and southeastern Kansas on the
Ozark Plateau. Expect similar conditions on Tuesday, as well.
Wednesday will bring our next best chance at rainfall across the
area. A short wave trough will begin to slide east and southeast
over the flattened 500mb ridge holding over the southwestern U.S.
Tuesday night. In response, a cluster of convection is expected to
initiate over portions of southern South Dakota, building south and
southeast into Nebraska through the early afternoon. If this complex
can maintain shear-cold pool balance, and from latest guidance of 0-
3 km shear and forward propagating corfidi vectors, it could
develop a wind risk as it progresses through the afternoon.
Between mid- range solutions, there remains uncertainty in the
track the complex will make, and thus the heaviest rainfall track.
Similar to spc, leaning toward the ECMWF, as it splits the
difference of the guidance. Expect the best chance for rainfall in
northern Missouri and far northeast Kansas to develop in the
afternoon hours. Given the progressive nature expected and lack of
rainfall as of late, flooding/heavy rainfall concerns are limited
to isolated heavy rainfall is possible.
Beyond Wednesday, precipitation will dwindle through Thursday as the
upper 500mb trough churns it's way eastward, leaving the Central
Plains and the lower Missouri Valley open to northwesterly flow.
Temperatures will remain seasonable, in the upper 80s and lower 90s
each day into the weekend.
Aviation...(for the 12z tafs through 12z Tuesday morning)
issued at 549 am CDT Monday Jul 16 2018
VFR conditions are expected to prevail through the period. A small
cluster of showers and thunder west of the Kansas City Metro is
expected to slowly evolve and move south of kmci and kmkc, but may
come close to kixd, enough for a vcsh mention. Winds will remain
light, primarily out of the north through the period.