Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 271742
AFDTOP

AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1242 PM CDT MON JUN 27 2016

...Update to aviation forecast discussion...

.SHORT TERM...(Today and Tonight)
Issued at 325 AM CDT MON JUN 27 2016

Early this morning the mid-level trough axis was centered just north
of the Great Lakes region. At the surface, the cold front that had
tracked across the forecast area yesterday was stretched across
southeast Kansas and was providing enough lift to support some
scattered showers and isolated storms along the
Kansas/Oklahoma/Missouri state borders.  Early morning dewpoints
were in the mid/upper 60s with temperatures cooling into the upper
60s/near 70 degrees, resulting in a moist environment present across
the area.  While some mid/high clouds were present across far
eastern Kansas, satellite imagery showed some breaks in the cloud
cover that, along with light or calm winds, may help to support some
patchy fog development around sunrise across the outlook area.

Early this morning another cold front was located near the South
Dakota/Nebraska border. Models show an embedded shortwave developing
along the western edge of the mid-level trough axis, and this
shortwave should help to push this cold front southward across
Nebraska today and near the Kansas/Nebraska border tonight. Expect
dry conditions during much of the daytime hours as the area becomes
wedged between the two cold fronts, with high temperatures topping
out in the low 90s.  Expect increasing precipitation chances late
afternoon into this evening across north central and far northern
Kansas with the approaching cold front. With little to no cap in
place and decent mid-level lapse rates, expect enough
destabilization to occur this afternoon across north central and
northern Kansas to result in 1500-2500 J/kg of MUCAPE. These
conditions combined with 30-40kts of 0-6km shear should support some
scattered thunderstorm development along the cold front. However,
there is still some uncertainty with regards to the coverage of
thunderstorm development across north central and far northern
Kansas as some models suggest that the best forcing may be focused
west of the forecast area.  Regardless, with these environmental
conditions in place, any storms that develop will have the potential
to become strong to severe with the main hazards being strong winds
and hail. Due to the uncertainty in the coverage of any thunderstorm
development, only have slight to chance PoPs in at this time for
tonight into Tuesday morning across north central and far northeast
Kansas.

.LONG TERM...(Tuesday through Sunday)
Issued at 325 AM CDT MON JUN 27 2016

The long term temperature forecast remains consistent with the
expected cooler temperature influx. Highs each day will be mainly
in the 80s, with some reliance and fluctuation based on any
daytime precipitation and related overnight could cover. All-in-
all, a period of relative consistency is expected for Tuesday
through next weekend.

This period of the forecast will also be impacted by multiple
short wave troughs moving through the relatively fast northwest
flow pattern that will set up overhead. The northwest flow will be
rather persistent through around Sunday or Monday when a shift
toward a more zonal pattern appears likely. Until that time,
expect multiple chances for thunderstorms on an almost daily and
nightly basis. Will focus on a few specific periods that perhaps
garner more interest from an impact and confidence perspective.

First, have added precip chances in northern Kansas on Tuesday
morning as a back door frontal boundary moves into the area from
the northeast. There is a strong model signal that the front will
interact with modest elevated instability to support scattered
thunderstorm development by sunrise on Tuesday, probably
diminishing as it builds to the south during the morning hours.
The rest of Tuesday into Tuesday evening will probably be dry.

Tuesday night into Wednesday will likely feature an MCS
developing over Nebraska and then building into Kansas as a strong
short wave and jet max moves across the region. There is a high
confidence in this convection developing, but a bit lower
confidence regarding the location and timing. The NAM/GFS are in
one camp in developing a forward propagating MCS Tuesday night
in NE and bringing it into KS by sunrise while other guidance such
as the ECMWF and Canadian models develop the convection a bit
farther east in Nebraska and bring it south into the area during
the day on Wednesday. Regardless of the specific details, western
parts of the forecast area seem to have the best combination of
shear and instability to support any risk of severe storms...and
MCS maintenance would seem to be more favored in those areas as
well so have continued to focus higher pops in western zones.

Wednesday night into Thursday morning shows a strong signal for
low level jet convergence and moisture flux convergence into
central and east central KS. Instability and effective shear are
not particularly impressive, but a relatively stationary
initiation zone and SREF pwat values in excess of 1.5 inches
suggest locally heavy rainfall is possible.

Widespread height falls and a boundary in the vicinity on Friday
and the likely passage of a stronger short wave trough aloft on
Saturday point to continued thunderstorm chances into the weekend
although details are less certain at this point.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1238 PM CDT MON JUN 27 2016

Scattered CU will develop at the terminals with bases of 4,000 to
6,000 feet. There may be an thunderstorm around the terminals late
this afternoon or this evening. High clouds from a thunderstorm
complex moving southeast across central KS will probably prevent
ground fog from forming by sunrise. However, if skies remain clear
there could be some patchy dense ground fog around the terminals near
sunrise Tuesday morning.

&&

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

$$

SHORT TERM...Hennecke
LONG TERM...Barjenbruch
AVIATION...Gargan



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