MONDAY
The start of the work week will feature
dry conditions and a warming trend. Highs by Tuesday should warm back
into the upper 70's.
TUESDAY
Models then bring a storm system out
into the central U.S. From Tuesday night into Wednesday. A fair
amount of spread remains regarding the eventual track of the surface
low associated with this system. Some models track it along the
Missouri/Arkansas border while others have it moving east across
central Missouri.
It does look like an elevated mixed
layer (EML) will advect over the region ahead of this system with
Gulf of Mexico moisture returning northward into the region. This
should lead to moderate amounts of instability (especially over
southern Missouri) as the system arrives Tuesday night. Deep layer
shear will also be supportive of organized convection.
One of the bigger questions to answer
is whether or not convection can fire along or ahead of an incoming
cold front given that a decent capping inversion will be in place. It
is quite possible that thunderstorms may be slightly post-frontal.
Regardless, CAPE/shear profiles alone are supportive of at least a
limited risk for strong to severe storms for Tuesday night and
Wednesday morning.
This system looks as if it will be
fairly progressive moving through. However, a widespread one to two
inch rainfall is quite possible across the region. With streams and
rivers already high, this may lead to some hydro concerns.
WEDNESDAY...
We may then see another day or two of
quiet weather behind the midweek system before active weather returns
by next weekend. Global models continue to indicate a large scale
setup that would favor more heavy rainfall and the potential for
strong to severe storms. Details regarding these potential hazards
will become clearer throughout the upcoming week.
THURSDAY ONWARDS
Confidence in a flooding event has
therefore become high enough to post a Flash Flood Watch (will be out
by 4 AM) for all of the Missouri Ozarks and extreme Southeastern
Kansas from Friday night through Sunday. Widespread storm total
amounts are still expected to be in the 3-6" range, but with a
caveat. With convective elements in play for the duration of the
event, locally higher amounts are quite likely (in the 8" plus
range). It is still a bit early to nail down where the heaviest rain
will fall.
Not to be outdone, the potential for
severe storms will also be present with this setup starting as early
as Friday night. South of that strengthening front, moderate amounts
of instability will be present with sufficient deep layer shear for
strong to severe storms. If supercells can develop, large hail to the
size of golf balls would be possible. The tornado threat will have to
be monitored as super cell motions would tend to parallel the front.
Even north of the front, elevated hailers will be possible.
The key to the severe potential Friday
night will be where that front sets up. The NAM has it draped across
south-central Missouri with the ECMWF a bit farther north. In
contrast, the GFS keeps it just south of the Arkansas border. We are
leaning towards that front at least making it as far north as
southern Missouri. The severe threat would then continue into
Saturday, especially along and south of where that front sets up.
The main upper level support for this
system will then pull through the region from Sunday into Sunday
night. The main shower/thunderstorm threat should begin to diminish
later in the day on Sunday, however some light wrap-around
precipitation will remain possible into Sunday night or even Monday.