Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 221732
AFDTOP

AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1232 PM CDT SUN MAY 22 2016

...AVIATION UPDATE...

.SHORT TERM...(Today and Tonight)
Issued at 409 AM CDT SUN MAY 22 2016

Early Sunday morning featured plenty of mid to high cloud cover
keeping temperatures on the warm side, ranging from the upper 50s in
far northeast KS to the low 60s under thicker clouds in central KS.
There were a few showers in central KS as well amidst weak
isentropic ascent and weak elevated instability. There is a small
chance for these showers to continue east into the forecast area
this morning but with such weak lift it seems to only be a slight
chance for light scattered precip if it makes it as far east as the
HWY 81 corridor. A steady stream of moisture was being pumped north
this AM on a 40-50 kt low level jet with a direct Gulf feed. This
will lead to markedly more humid conditions in the area today with
dewpoints climbing into the 60s. Warmer air will also be incoming,
and highs are likely to approach 80 degrees today across the entire
area with no precipitation expected from late morning through the
evening.

Overnight tonight, a weak vorticity maximum is expected by all model
guidance to bring increased vertical motion to central and eastern
Kansas after midnight. The low level jet will be in place again
with continued moisture advection. Model forecast soundings
indicate that most elevated parcels will have a good amount of
convective inhibition through much of the night but a modest
increase in mid level lapse rates in addition to the influx of low
level moisture should provide decreasing stability with time and
the vort max is likely to be sufficient to initiate elevated
thunderstorms probably in the 4-7 AM time frame. A few strong
storms are possible, but effective shear for these parcels is not
particularly strong and the instability is moderate at best so
despite some aggressive convection-allowing- model
interpretations, currently believe that the severe potential
through sunrise Monday is on the low end.

.LONG TERM...(Monday through Saturday)
Issued at 409 AM CDT SUN MAY 22 2016

Monday through Saturday ...

This upcoming week continues to look active with the potential for
thunderstorms every day as surface and mid-level features remain
fairly persistent.  A broad mid-level trough will remain anchored
across the western U.S. with the forecast area staying wedged
between surface high pressure over the eastern U.S. and surface low
pressure to the west across portions of the High Plains and Central
Plains.  With these features in place, expect persistent southerly
flow to support continued moisture advection and warm-air advection
into the region to help reinforce conditionally unstable conditions
essentially every day this week.

Monday may be an active weather day as an ongoing MCS from late
tonight will likely still be progressing eastward across the CWA
Monday morning, resulting in some widespread moderate to heavy rain
at times.  Once this morning MCS exits to the east, there is the
potential for the atmosphere to destabilize enough through the
afternoon to help support additional thunderstorms late Monday
afternoon through Monday night.  Models show a cold front stretching
across western Kansas and possibly nosing toward north central
Kansas Monday evening. This boundary combined with the development
of an embedded shortwave over south central Nebraska should help to
spark thunderstorm development. With ample instability and increased
shear by Monday evening, some strong to severe thunderstorms will be
possible across the entire outlook area and have likely PoPs for
Monday and Monday night.

With the surface and mid-level features remaining fairly unchanged
with additional embedded waves and persistent southerly flow helping
to reinforce instability across the area, expect ongoing chances for
thunderstorms throughout the remainder of the week.  However, with
each day the timing and location details of thunderstorm development
will be dependent upon what lingering outflow boundaries are in the
area from earlier convection and whether or not the atmosphere has
enough time to recover to support the development of additional
strong to severe storms.  With these uncertainties in the timing and
location of storms, have kept just chance PoPs in the forecast for
Tuesday through Saturday.  However, the persistent moisture
advection will help to support sufficient instability across the
area through the week.  Models suggest that 0-6km shear values may
be stronger in the 30-40kt range by mid to late week. Additionally,
the cold front should begin to extend into at least north central
Kansas by Wednesday and remain anchored there through Saturday. This
boundary combined with the dryline advancing further east into at
least central Kansas should aid in the initiation of thunderstorms
that would likely advance eastward across the forecast area.  As a
result, most of the forecast area has been outlooked in a Slight
Risk by SPC through Tuesday with Thursday and Friday also looking to
be days with a decent potential for some strong to severe storms.
With all of the strong to severe thunderstorm potential this week,
all severe modes may be possible: large hail, damaging winds,
possibly a few tornadoes, and several days with some moderate to
heavy rainfall which may result in an increasing threat for flooding
throughout the week. With this steady pattern in place, expect
fairly consistent temperatures with highs in the mid 70s to mid 80s,
and low temperatures remaining mild in the 60s.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 1232 PM CDT SUN MAY 22 2016

Biggest uncertainty is what will trigger TS over the next 24
hours. Models suggest a subtle wave within the southwest flow
aloft, which may be enough give the instability with little
inhibition. Hi resolution models show potential for TS by Monday
morning so have included a VCTS in the terminals. Other concerns
include when restrictions to CIGS may move in as low level
moisture continues to advect into the area. Have left CIGS above 2
KFT for now, but there is the potential they could be lower. Also
forecast soundings are suggesting some possible LLWS late this
evening as a nocturnal inversion sets up and the low level jet
increases. Am reasonably confident that VFR conditions will
prevail into the early evening. Chances for deteriorating
conditions will increase towards dawn Monday.

&&

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

$$

SHORT TERM...Barjenbruch
LONG TERM...Hennecke
AVIATION...Wolters


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