Area Forecast Discussion
Issued by NWS Topeka, KS

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404
FXUS63 KTOP 290821
AFDTOP

AREA FORECAST DISCUSSION
National Weather Service Topeka KS
321 AM CDT SUN MAY 29 2016

.SHORT TERM...(Today and Tonight)
Issued at 313 AM CDT SUN MAY 29 2016

08Z profiler data shows relatively modest mid level flow over
the central plains as water vapor imagery shows a quasi-zonal
flow over the state. Slow moving upper level low pressure systems
were noted over MN and southern CA and a closed low was seen over
British Columbia. At the surface, low pressure was weakening over
the upper Midwest while another area of low pressure formed near the
TX big bend.

For today the forecast is going to depend on mesoscale features as
models show modest mid and upper flow persisting over the forecast
area. Profiler data from KICT and KTLX show low level winds becoming
more southerly allowing from moisture over the southern plains to
begin moving back into southwestern KS. Models prog some isentropic
upglide over southwest KS and satellite shows an area of AC where
the models have the upglide. This area could end up being where
convection initiates this morning, setting the course for the rest
of the day. The NAM seems to favor this idea with a possible MCV
drifting east along the KS/OK boarder. However the GFS and HRRR cast
some doubt on this idea. In any case, there does not appear to be an
obvious boundary for low level convergence to force a parcel up and
a lack of a well defined shortwave makes it difficult to highlight
one area over another for precip chances today. If storms are to
form over southwestern KS this morning, the resulting outflow could
provide the low level focus for additional development later in the
day. In general the forecast favors precip chances more across the
southern half of the forecast area since mid level flow is nearly
zonal and the low level moisture advection appears to be south of
the area. Model progs show reasonable instability developing through
the day so there is a conditional chance for precip. I just don`t
have much confidence in what that conditions may end up being. 0-6km
shear is expected to remain rather weak through the day so chances
for organized convection appear low. So there may just be pop up
storms to deal with during the heating of the day. With this in
mind, have kept POPs in the 20 to 30 percent range today. With
decent insolation today, highs are expected to warm into the lower
80s as forecast soundings mix the boundary layer above 850MB.

For tonight, generally only carry a slight chance for precip
expecting the boundary layer to begin stabilizing with the loss of
heating and again no obvious wave within the flow. The low level jet
is progged to set up over the western half of the state with speeds
generally between 30 and 40 KTS. So there isn`t much of a warm air
advection signal for elevated storms tonight either. Lows are
expected to remain in the lower and mid 60s as southerly low level
flow prevails overnight.

.LONG TERM...(Monday through Saturday)
Issued at 313 AM CDT SUN MAY 29 2016

Sfc lee trough develops over western KS in response to the incoming
shortwave trough from the northwest on Monday afternoon. Given the
warm and moist airmass in place, latest guidance is showing
difficulty in locating the exact source of forcing and appears to be
overdoing qpf amounts, especially the ECMWF. Forecast sides closer
to the GFS and NAM solutions which develops scattered showers and
storms during the late afternoon. Confidence in precip increases
overnight Monday as the wave nears, developing an mcs over central
NE, tracking through the area through Tuesday. Likely pops were
placed here with PWAT values over an inch at times. Assuming lower
flash flood guidance values which is dependent on whether we see
rainfall Sunday or Monday, localized flooding could once again
occur.

Models clear out the trough Wednesday evening with cooler and drier
northwest flow in its wake. Clear skies and light northerly winds
drops temps below average values in the lower 70s for highs and lows
in the 50s through Friday. Upper ridge continues to dominate the
Inter Mountain west through the weekend as the CWA resides on the
eastern edge. Shortwave troughs traversing the eastern edge may
bring chances for thunderstorms Saturday evening into Sunday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1148 PM CDT SAT MAY 28 2016

Still appears at least some chance for shallow fog though radars
and surface obs still showing some wind. Moisture increases in the
mid levels Sunday but little confidence in any impacts from
precip at the terminals.


&&

.TOP Watches/Warnings/Advisories...
NONE.
&&

$$

SHORT TERM...Wolters
LONG TERM...Prieto
AVIATION...65



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