Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 261745
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1245 PM CDT Mon Jun 26 2017

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 304 AM CDT Mon Jun 26 2017

A broad longer wave length trough continued be centered across the
east central conus. The longer wave length upper trough will shift
slightly to the east later tonight.  Northwest flow at mid and upper
levels will continue across the plains. Early this morning a
shortwave upper trough, embedded with the northwesterly flow aloft,
was noted on WV satellite across central SD.

The H5 trough across central SD will dig southeast across eastern NE
into extreme northeast KS and central MO by 00Z TUE. The ascent
ahead of the H5 trough combined with weak isentropic lift at 305K
theta surface will provide the chance for isolated to scattered
showers through the day. On average the QPF will be 0.10" or less
across the CWA. MUCAPE/CAPE will be in the 100-700 J/KG range,
enough to hear a clap of thunder with the showers. Highs will once
again be cool with mid 70s across the northeast counties to around
80 across the southwest counties of the CWA. Skies will be mostly
cloudy, though there could see some breaks in the cloud cover at
times.

Tonight, the H5 trough over western MO will dig southeast into the
mid MS river valley. A surface ridge of high pressure will build
southward across eastern NE into northeast KS. The northeast sfc
winds should push the boundary southward into northern OK. The
showers across the southern counties during the early evening hours
will shift southeast of the CWA. As the ascent ahead of the H5
trough moves southeast across northern AR and southern MO. The
weaker isentropic lift north of the boundary will shift southward
across southern KS during the mid evening hours. Overnight lows will
dip down into the mid to upper 50s.

.LONG TERM...(Tuesday through Sunday)
Issued at 304 AM CDT Mon Jun 26 2017

On Tuesday a mid level trough will track over the northern and
central Rockies aiding in the develop of storms along the front
range and high plains in the afternoon. Several storm clusters
progress eastward across northwest KS and western NE during the
evening. By midnight it appears these storms try to reach north
central KS and the remaining forecast area through out the morning.
These storms will be fighting the surface inversion by this time of
night so the clusters may become less organized. Although, the
resulting outflow may become the focus for additional development
across eastern KS. The models show instability still in place and
a strong low level jet so perhaps a few storms may be strong.

The main shortwave eventually pushes a cold front towards the
forecast area on Wednesday. The models begin to disagree with what
occurs during the afternoon through the overnight. The EC develops
convection in southeast NE along the front and moves it southward
overnight. The GFS is showing isentropic lift over the area and
decent instability above those layers leading to convection. The
NAM is showing an MCS develops in northeast CO and moves through
the area overnight. This will have implications on the set up for
Thursday as all the models show a surface low deepening in
southwest KS. Plenty of instability and shear will be in place to
support organized convection. Widespread storms appear regardless
as a shortwave digs over the region and pushes the cold front
through eastern KS. A more stable air mass filters in behind the
front, but models are still showing embedded waves in the
northwest flow that could bring chances for precipitation next
weekend.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1243 PM CDT Mon Jun 26 2017

Cloud cover will continue to scatter throughout the afternoon
hours. A surface boundary could spark a few thunderstorms this
afternoon in the 20 to 23Z timeframe at all terminals. Otherwise,
winds will remain from a northerly direction and remain below 10
knots.

&&

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

$$

SHORT TERM...Gargan
LONG TERM...Sanders
AVIATION...Baerg



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