Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 231722
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1222 PM CDT Mon Mar 23 2015
Issued at 1033 AM CDT MON MAR 23 2015
Have updated the forecast with current temperatures and anticipated
afternoon temperatures. This resulted in a slight trend downward for
much of the forecast area. For northern and northeastern Missouri
this change was more significant as lower clouds are streaming into
that area, wrapping around the low-level circulation center. Also,
northeasterly winds should help keep temperatures in check across
that portion of the forecast area. So temperatures in our
northeastern zones will be in the upper 40s to near 50 degrees, while
areas south and west will climb into the 50s and lower 60s.
Issued at 415 AM CDT MON MAR 23 2015
...Active period of weather tonight through Wednesday...
Currently through today:
Weakening surface low is currently centered in northern MO near
the IA border and will continue to make its trek off toward the
ESE through this morning. A few showers had briefly popped up
ahead of its center but have already been dissipating as they hit
drier air in northeastern MO. As for PoP chances through the rest
of the overnight period, that`s pretty much it for the night and
really through the rest of the day today. Highs will be cooler
today as compared to yesterday with northerly flow becoming
easterly by the end of the day. A benign weather day is expected
but will not last long....
Tonight through Tuesday Night:
Upper trough just now beginning to enter into the Pac NW is
progged to force cyclogenesis on the lee side of the Rockies, which
is the system to watch for during this time frame. This
negatively-tilted trough axis is expected to have its southern tip
fuel the low that will approach and cross this forecast area by
tomorrow night. Ahead of the developing/approaching low, E-W
oriented surface boundary will setup and drape itself across
central MO by later tonight, allowing for a focus for convection.
Nocturnal LLJ will commence tonight and combining this with decent
moisture transport ahead of the low, supportive mid-level lapse
rates and MUCAPE, and 0-6km bulk shear values at 50 to 60+ kts.
(according to the 00Z GFS), elevated convection will allow for the
primary weather concerns to be moderate to heavy rainfall along
with some hail. Considering that the convection overnight Sunday was
reported to have been able to produce enough graupel/small hail to
cover the ground in central IA, hail potential will be something
to continue to watch with any stronger storms that develops
tonight through Tuesday.
As for Tuesday, model soundings can`t agree with the setup for the
afternoon hours. While convection is likely Tuesday, the question
is how any morning convection will influence the afternoon storms`
development and strength. If the atmosphere is able to recover in
between any morning convection and afternoon development, could
see higher potential for strong to severe storms with winds and
hail being the primary hazards. Current forecast looks to keep the
bulk of the severe weather potential just outside of this forecast
area, to the south and east. However, any shift further westward
or northward with a more supportive environment could easily
bring the severe threat into this area. Especially considering
that this is the first event of the season/year for this region,
certainly a system to continue to monitor.
Wednesday through Wednesday Night:
Additional shower/storm chances will reappear later in the day on
Wednesday as another surface low tracks across central/southern
MO. This low is out ahead of a positively-tilted upper trough and
while there appears to be good support for convection with this
system in the afternoon and evening hours on Wednesday, the better
dynamics aloft should hang back just enough to be offset from the
more supportive thermodynamics to keep widespread severe chances
at bay in this forecast area, keeping the higher threats off
toward the south and east. Again though, any shift of a more
supportive environment into this forecast area on Wednesday will
enhance the severe weather threat, especially since this
convection should have no hindrance from any morning convection
and will have plenty of time for diurnal heating to set the stage.
Continue to monitor this situation as well as the time approaches.
Thursday through the remainder of the forecast period:
The convective period dominating the first half of this week will
shutoff as much cooler air arrives Thursday through the early part
of the weekend. NW flow will return and surface high pressure of
Canadian origin will mosey into the region, allowing for benign
conditions to prevail. The coolest day of this time frame will be
Friday with widespread 40s anticipated, thanks to an upper trough
swinging through the Great Lakes and into MO, advecting below
normal temps in. Temps will recover relatively quickly, rebounding
into the 60s by the end of the weekend.
.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1222 PM CDT MON MAR 23 2015
VFR conditions are expected through the afternoon and evening hours.
A complex of thunderstorms is expected to form over late tonight over
central to eastern Kansas and spread east-northeast into northwestern
Missouri. This should affect areas mainly from Kansas City northward.
Showers, storms and low ceilings are expected with this activity.
This heavier precipitation should lift north of the terminals after
sunrise and from there the forecast gets a little murky, and perhaps
not in a figurative sense. Forecast soundings for Tuesday morning
show a mix of low clouds, possibly IFR, and decreased visibility
which may be some drizzle based accompanying model QPF fields. This
notion seems to make sense given the track of the surface low should
be near to perhaps just south of the terminals and then into