Scientific Forecaster Discussion
fxus63 keax 171125
Area forecast discussion
National Weather Service Kansas City/Pleasant Hill MO
525 am CST sun Nov 17 2019
issued at 310 am CST sun Nov 17 2019
Primary forecast focus is on rain chances today.
1. Light rain chances will increase through the late morning and
afternoon hours; primarily across portions of southwest, central and
north central Missouri. Rainfall amounts will be minor, a trace to a
tenth or two of an inch.
2. Greater rain chances will exist midweek, Wednesday through
Thursday. The best chance for rain will exist Wednesday night
through early Thursday morning. A half inch to an inch can be
expected across the region, with some locally higher amounts, close
to an inch and a half, possible in some locations.
This morning, stratus continues to build in from the west and south
in response to the approaching open short wave trough. 08z surface
analysis reveals the weak surface boundary is just about to push
into northwestern Missouri, extending into south central Kansas.
Most short range guidance is in relative agreement of initiation of
showers and rain around sunrise, continuing through mid to late
afternoon. Expect skies to improve across eastern Kansas and western
Missouri an hour or so before sunset.
Midweek, the forecast remains on track with ridging over the Midwest
ahead of a Stout low wrapping up and slowly evolving over the West
Coast. An open 500mb short wave trough will kick east-northeast
around the parent trough with increasing warm air advection through
Wednesday. Ample forcing for ascent will result, with strong
isentropic ascent spreading over the region. Pwat values, midweek,
will be off the charts, climatologically speaking, with values
forecast over an inch to an inch and a half, well above the 90th
percentile for this time of year. In response, expect efficient
rainfall production Wednesday night through Thursday morning. First
guess at amounts is widespread one to one and a half inches.
For next weekend, rain chances will exist Friday into Saturday, as
the western trough finally moves across the Southern Plains. Long
range guidance has continued to struggle with this solution, flip-
flopping over the past few days. However, the general trend of rain
anywhere from the Ozarks into northern Missouri has persisted.
Better chances still appear to reside from the Southern Plains,
across Arkansas into the Missouri Ozarks. Some mix of rain and snow
may be possible overnight Friday into Saturday morning; however,
temperatures will warm into the 40s for highs during the day,
negating much in the way of winter impacts.
Aviation...(for the 12z tafs through 12z Monday morning)
issued at 513 am CST sun Nov 17 2019
A frontal boundary approaching from the northwest will reach taf
sites early in the period. This will result in a shift from
southwesterly winds to more west and northwest. Still anticipating
some rain scattered across the region. At present time, the
greatest rain chances will exist from the Ozarks into central and
northern Missouri. Lacking confidence any rain will impact area
airfields, so will stick with a drop to MVFR and hold off on -ra.
Ceilings will return to VFR through the evening and remain there
through the remainder of the period.