Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 221122

Area Forecast Discussion
National Weather Service Topeka KS
622 AM CDT Thu Jun 22 2017

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 248 AM CDT Thu Jun 22 2017

Outflow from storms in south central NE last evening has pushed
southeastward into our area. A 40 kt low level jet out of the south
has intersected this outflow and this along with residual moisture in
that layer has supported additional storm development in north
central KS. The SPC meso analysis and short term models show that
as these storms move eastward the moisture and elevated cape
decreases so this activity should begin to weaken. Mid to high
clouds will likely linger through the morning, but mostly sunny
skies allows highs to reach the 90s again today. This evening a
stronger cold front pushes into the forecast area. Scattered shower
and storms are possible along the front although the chances remain
relatively low. A majority of the models show poor moisture quality
across north central KS when the front arrives. Further south the
low level moisture is better, but a strong cap remains in place.
Later in the evening mid level moisture appears to improve although
cin continues to be an issue. The relatively steep mid level lapse
rates may contribute to enough instability for storms if any to
produce small hail and strong wind gusts, but widespread severe
storms are not likely. Also, the deep layer shear is fairly weak to
support severe activity. Late tonight perhaps the mid level height
falls and forcing along the fronts aloft will allow for more shower
and storm coverage. In fact most of the models show most of the
precipitation is post frontal and mainly after midnight.

.LONG TERM...(Friday through Wednesday)
Issued at 248 AM CDT Thu Jun 22 2017

The model consensus has the cold front pushing south of the
forecast area Friday morning with dryer air moving south behind
it. So precip chances should be diminishing through the morning.
After that a surface high pressure system is progged to remain
over the central plains through Monday with northwest flow
overhead. This pattern favors cooler temps. The biggest
uncertainty involves mesoscale features and the prospects for
light precip. The ECMWF remains the biggest question mark as it
develops a surface low over southeast CO and bring warm air and
moisture into central KS on Saturday as a result of the surface
low. None of the other guidance has anything as strong in the
MSLP prog, although they do develop weak warm air advection (WAA)
into southwest KS and southeast CO. With the majority of solutions
showing a weaker WAA pattern further southwest of the forecast
area, have favored a dry forecast for Saturday night into Sunday
morning and only have some slight chance POPs across north central
KS Saturday afternoon in case the WAA gets an isolated shower to
form. Models show little if any instability and forecast soundings
even indicate an inversion in place over the layer where the WAA
is progged to occur so thunder appears to be unlikely. By Sunday
afternoon and Sunday night, there are some indications from the
models for some energy moving through the northwest flow aloft
while lapse rates gradually steepen. So have some small POPs in
the forecast for this.

Better return flow is anticipated for Tuesday and Wednesday as the
surface high pressure weakens and moves to the east. This should
allow for low level moisture an instability to return to the
region. Models suggest there could be a low amplitude shortwave
move through the plains as the synoptic pattern deamplifies.
However models develop a fair amount of inhibition with an
elevated mixed layer advecting over the area as well. Regardless
of the CIN progs, the models seem to agree on decent QPF Tuesday
night into Wednesday. So the forecast has some chance POPs towards
the end of the forecast.

Temps look to be below normal for Friday through Monday as the
surface high pressure system remains over the central plains.
Temps should trend back to and above normal by the middle of next
week as southerly low level flow brings warm air back north.


.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 619 AM CDT Thu Jun 22 2017

A few showers and storms may linger around MHK for the next few
hours otherwise VFR conditions expected through this evening. Late
tonight a front will move through the taf sites causing a wind
shift to the north. There is a chance for showers and storms along
and behind the front. Also, models are hinting at the possibility
of MVFR stratus moving in towards the end of the taf period.




SHORT TERM...Sanders
LONG TERM...Wolters
AVIATION...Sanders is the U.S. government's official web portal to all federal, state and local government web resources and services.