Scientific Forecaster Discussion
fxus63 keax 192334
Area forecast discussion
National Weather Service Kansas City/Pleasant Hill MO
634 PM CDT Thu Apr 19 2018
issued at 149 PM CDT Thursday Apr 19 2018
Northerly surface flow and resulting cold advection from this
morning has transitioned to northeasterly as of the early afternoon.
This trend will continue as a surface high over north central Iowa
pushes eastward, eventually bringing a brief period of weak warm
advection as surface flow transitions to southeasterly by Friday
afternoon. Upper-level ridging will maintain dry conditions and
mostly clear skies from now until Friday afternoon/evening.
Another cold night awaits tonight into Friday morning underneath
mostly clear sky conditions, combined with the residual cool air
mass currently in place. Conditions are once again favorable for
patchy frost early Friday morning. Overnight lows hover near
freezing for northeast MO, with values in the mid 30s elsewhere. A
brief warming trend then will push Friday afternoon highs back
into the 60s, albeit low 60s, for most of the area.
A deep upper low now centered over the West Coast will continue to
deepen and advect over the southwestern Continental U.S. By Friday night. While
the attendant surface low will remain well south of the cwa, local
slightly enhanced 850 hpa flow underneath associated positive vorticity advection ahead of
the upper low may promote light rain showers as early as Saturday
morning. Latest model soundings suggest a less impressive dry layer
in the lower levels compared to previous runs, which would provide
an earlier onset of precip Saturday morning as well. With all said,
though, still expecting only brief periods of light rain Saturday
morning and afternoon, mainly south of the Missouri River as
overall forcing remains meager at this point, and better moisture
supply remains pinned further south. Additional light
precipitation is possible early Sunday, as the low level jet increases
coincident with the passage of the mid to upper low. This should
mark the first Sunday in April with no snow in the area.
Next week looks to be much more pleasant in terms of temperature
trends. A cold frontal passage Tuesday night and precip chances
ahead of the boundary will moderate an early week warming trend,
though temps will still be much closer to seasonal compared to
those as of late.
Aviation...(for the 00z tafs through 00z Friday evening)
issued at 633 PM CDT Thursday Apr 19 2018
VFR conditions throughout the period with a easterly 5-10kt wind
throughout the night. Winds will shift to the southeast in the late
morning and pick up to 10-15kts with a solid high cloud deck
pushing into the area from the northwest.