Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 230913
Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
413 AM CDT SAT APR 23 2016
Issued at 412 AM CDT SAT APR 23 2016
Today - Tonight:
In the very near term will be dealing with patchy dense fog over the
northeast 1/2 of the CWA. The fog and stratus is forming under a
surface ridge with river valleys and low lying areas the most
susceptible. The latest NAM/RAP 925mb condensation pressure deficit
prog best depict the low clouds with the SREF favoring more
widespread dense fog further north in IA.
Otherwise, for today expect a nice warm up as pressure falls over
the Central Plains induce increasing southerly winds. Should see
decent mixing with a dry adiabatic lapse rate yielding highs around
10 degrees above average. Upper level ridging spreading east into
the CWA will provide for continued dry conditions.
Increasing warm air advection aloft will ensue across KS and NE this
evening with scattered elevated convection possibly grazing far
northwest MO towards sunrise Sunday morning. Any convection which
reaches this region should fall apart Sunday morning with convective
debris and mid level accas likely lingering over the western CWA
into the afternoon.
Sunday - Sunday night:
The weather will become more interesting late Sunday afternoon into
the evening as an upper level closed low migrates into SD/NE. A
negatively tilted shortwave trough is progged to rotate from under
the upper low and lift northeast across KS and NE during the
afternoon. A moderately strong low level jet around 45kts will pull
deeper low level moisture ahead of a north-south dryline which will
anchor over central KS and far western OK. Expect to see scattered
strong/severe convection form along the dryline by mid/late
afternoon and track quickly northeast. Far northwest MO stands the
best chance of seeing active convection. Surface based CAPEs around
1500 J/kg and 0-6km shear around 40kts will support
strong/marginally severe storms over this area. All models strongly
suggest the dryline will move little to the east so the severe
threat in the CWA will likely be limited to far northwest MO.
Convection will weaken and decrease in coverage as it moves east
through the CWA with the far southeastern counties receiving the
Monday - Friday:
A fairly active period with two more closed upper lows likely
affecting the region. While Monday initially looked relatively quiet
as the Upper MS Valley system pulls away there is some concern that
some afternoon convection could form along the remnants of a stalled
surface boundary. The limiting factor will be increasing mid level
heights and a lack of upper support. Nonetheless with a front in the
CWA will need to be vigilant.
As we`ve been discussing over the past few days a second and
stronger upper system will become a factor and play a significant
role in our weather by Tuesday night and continuing into Wednesday.
Medium range operational models continue to eject a negatively
tilted shortwave through KS and MO. There is every reason to believe
a west-east frontal boundary will be in the vicinity with this
feature lifting north and through the CWA. Low-level moisture will
not be a problem with low/mid 60 dewpoints likely south of the front
and spreading northward. The GFS indicates 2000-3000 J/kg of CAPE
could be available with 30-40kt 0-6km shear so severe storms are a
growing concern. As always timing of the front and convective
development will determine where severe will occur but our CWA is
currently within the window of opportunity.
Convection could linger well into Wednesday as the upper low opens
up and lifts through NE/KS/IA/MO.
Thursday looks quiet as we`ll be between systems. The third system
we`ll be keeping an eye on will be yet another closed upper low.
This feature may not be a factor until late Friday.
Through out this period expect to see above average temperatures with
an overall increase in humidity.
.Aviation...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1207 AM CDT SAT APR 23 2016
Added a TEMPO group to the terminals for early morning haze and
perhaps a very brief period of CIGs around 3 kft. These restrictions
should not persist very long after sunrise. Winds will generally be
out of the south around 10 kts with occasional gusts to around 20