Area Forecast Discussion
Issued by NWS Springfield, MO
FXUS63 KSGF 181143
Area Forecast Discussion
National Weather Service Springfield MO
643 AM CDT Tue Apr 18 2017
...12z Aviation Update...
.SHORT TERM...(Today and tonight)
Issued at 221 AM CDT Tue Apr 18 2017
Low stratus has redeveloped in some areas southeast of the higher
elevation of the Ozarks Plateau where low level moisture and
upslope flow has developed with an e to se sfc winds. Will
continue to monitor for fog (either radiation or stratus build
down). KBBG/Branson Airport is down to 300 ft and 3 miles in fog
as of 2 am, and would think the best fog potential will be down in
Stratus may be stubborn to burn off in some spots this morning,
but once it does it should be a nice/quiet/mild day. Light winds
will veer to the south with a frontal trough moving into IA/KS
late by late in the day. A shortwave moving through the Midwest
will shift onto the east tonight and the front will stall off to
our north as another wave/sfc low moves into the Central High
.LONG TERM...(Wednesday through Monday)
Issued at 310 AM CDT Tue Apr 18 2017
Potential weather impacts during this period include some
marginal severe storm potential, primarily late Wednesday night
into Thursday with a frontal passage, then heavy rain potential
Friday and Saturday with possible flooding.
The period Thu-Sat will be active with a frontal boundary
expected to move through the region late Wednesday night and
Thursday, then likely stalling off to our south late in the week.
Synoptic scale lift will increase along the frontal zone with a
good chance for periodic showers/a few thunderstorms Friday into
early Saturday as an upper level low slowly approaches and moves
through our region.
Wed-Wed night: A front off to the north to start the day will
begin to move southeast toward our area as another shortwave moves
from the central Plains into the Midwest. The air mass ahead of
the front will be very warm and relatively dry aloft. A veered
low level wind profile with sw sfc winds will aid in warming
afternoon temperatures into the 80s with GFS MOS guidance showing
mid 80s over southeast KS/far sw MO into central MO. A sfc low
center will track from southern NEB through IA late Wed and Wed
night with a trailing sfc front reaching the northwest cwfa by
12z/7am Thu. Global models do edge in some chances for
showers/tstms late Wed night into our nw cwfa (where the edge of
an day 2 SPC marginal risk is depicted), but better chances for
showers/tstms will likely hold off until Thu.
Thu: The front will gradually become oriented more west-east as it
shifts south through our area. Afternoon GFS depicted mlcape
values of 1000-1500 j/kg and 30kt 0-6km vertical shear could
support some strong storms with a wind/hail threat, but the with
the front and mid level flow becoming increasingly parallel the
window of opportunity for stronger storms may be relatively short
Thu night-Fri-Sat: ECMWF/GFS/GDPS are all similar in the handling
of an upper level jet digging southeast through the southern
Rockies, eventually developing a closed upper low over eastern
CO/western KS Fri afternoon. The GFS is a bit stronger versus
other guidance and the ECMWF is slightly faster. Overall lift
will increase as the the upper low and the exit region of the
upper jet approach. Guidance is all similar in stalling the sfc
front to the south over OK/AR, but periods of heavy showers will
develop north of the sfc front as the upper system approaches.
Precise timing of the heaviest rain is still in some question, but
in general Fri-Fri night-early Sat look like the period to focus
on. Storm total rainfall of 2-4 inches over a large area is in our
gridded forecast, and rainfall of this magnitude if realized will
produce the widespread flooding of creeks, rivers, low water
crossings, etc. Friday and through the weekend.
Sunday-Mon: The upper level low will shift east of the area.
Sunday. Depending on the timing some light showers/clouds could
linger into Sunday with cool temperatures. Monday looks quiet with
sfc high pressure moving through.
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 643 AM CDT Tue Apr 18 2017
Patchy fog/low stratus will continue across portions of the area.
Although more sporadic in nature, went ahead and kept some
mention in for JLN and SGF. BBG will be the most impacted. Low
clouds and fog should dissipate by mid to late morning. VFR
conditions are expected from then through the end of the period.
Generally light winds (less than 10kts) can be anticipated. LLWS
may be possible for JLN later tonight and/or just prior to sunrise