000
FXUS63 KTOP 121730
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1230 PM CDT Sat Jul 12 2014

...AVIATION UPDATE...

.SHORT TERM...(Today and Tonight)
Issued at 300 AM CDT SAT JUL 12 2014

Convection along the front across Nebraska may send some weak
outflow in to the area later this morning, but do not expect much
change in sensible weather as a result.  Overnight lows remain in
the 70s with southerly winds.

Expect a hot day today as many locations mix toward 800 MB and bring
afternoon surface temperatures into the middle 90s with some upper
90s west.  Will see heat indices this afternoon in the 98-102 range
once again.  With a shift in winds to the southwest, drier air mixes
into the column as the day progresses. By the time the front moves
toward our forecast area assisted by a weak upper wave, think not
only will there be limited instability to work with but much of the
precip that is generated will go into saturating the lower levels.
Have adjusted PoPs down just a bit to accommodate this, but generally
spread isolated to scattered storm chances from NW to SE from 0z to
12z Sunday. Overnight lows in the upper 60s north to low 70s south
expected.

.LONG TERM...(Sunday through Friday)
Issued at 300 AM CDT SAT JUL 12 2014

By Sunday morning the front should have pushed south of interstate
70 with remnant showers and thunderstorms from overnight convection
along and behind the front. Slight chances remain through the
remainder of the day as the front slides south out of the forecast
area. The better chances appear to be in east central KS during the
morning and early afternoon hours. The mid level support looks to be
limited due to the shortwave located well to the east. Soundings
also show a rather deep layer of low level dry air that precip will
have to overcome to reach the surface. This initial surge of cold
air and cloud cover means high temperatures remain generally in the
mid to upper 80s. Then Sunday night and into Monday the strong
closed mid/upper level low pressure drops out of Canada into the
Great Lakes region. This will bring a reinforcing shot of cold air
as well as additional mid level lift. More widespread showers and
thunderstorms are possible on Monday as this low passes to our
northeast. The instability on Monday may be limited after the
initial front although the deep layer shear associated with the
strong low does increase. Still widespread severe weather seems
unlikely at this point. Precip quickly clears the area by Monday
evening as dry air advects southward into the region. Unseasonably
cool air still on track to arrive by Tuesday morning and last
through Thursday therefore did not make any changes to the extended.
Models continue to bring moisture back into western and central KS
within the return flow as weak shortwaves track overhead within
the northwest flow. Have kept the forecast dry for now but western
areas could see slight chances mid week if things trend eastward.

&&

.AVIATION...(For the 18Z TAFs through 18Z Sunday Afternoon)
Issued at 1230 PM CDT SAT JUL 12 2014

VFR conditions should prevail through this evening due to the
surface front remaining north of the terminals while mid level
ridging sits overhead. The NAM and GFS show a decent band of mid
level frontogenesis collocated with some saturation directly behind
the surface front. Because of this think high based SCT SH and
embedded TS are possible on the north side of the boundary as it
moves south late tonight. Therefore have maintained a VCTS for the
early morning hours. Elevated instability appears to be limited so
precip looks to be light and there may not even be a VSBY
restriction with the precip. Will have to reevaluate this as the
front gets closer.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...67
LONG TERM...Sanders
AVIATION...Wolters