Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 071101

601 AM CDT Mon Jul 7 2014

...Update to aviation forecast discussion...

.SHORT TERM...(Today and Tonight)
Issued at 311 AM CDT MON JUL 7 2014

A broad mid-level trough stretched across much of the northern and
northeastern U.S. with a mid-level ridge in place over the
southwestern U.S. A surface trough gradually shifted southward into
the region early this morning, becoming centered over the forecast
area with an associated cold front progressing into northern Kansas.
Water vapor imagery showed a weak embedded wave that developed
across southern Nebraska within the northwest-to-southeast oriented
zonal flow. Weak isentropic lift was noted over this area
north of the cold front. This lift combined with upwards of 2000
J/kg of MUCAPE resulted in scattered elevated thunderstorms
developing over far southeastern Nebraska, and these storms are
expected to track southeastward into northeast Kansas. While radar
trends shows these storms being fairly pulsey, cannot rule out some
marginally severe hail with the strongest storms. Latest short range
models show this activity skimming across northeast and far eastern
Kansas, diminishing in coverage by mid to late morning as it
progresses into Missouri.

Another hot and humid day is in store for the region. The day is
starting out mild as overnight low temperatures only dropped into
the 70s. Models show the cold front getting hung up across northern
Kansas this morning but then gradually lifting north of the region
this afternoon, keeping much of the forecast area in the warm sector
today. Soundings suggest decent mixing should occur with a nose
of 24-29C 850mb temperatures extending into the region. As a result,
expect afternoon high temperatures to reach into the mid to upper
90s (and possibly near 100 degrees) across much of the forecast
area, however slightly cooler conditions are possible for locations
near the boundary across far northern Kansas. Dewpoints are expected
to stay in the mid 60s to low 70s, resulting in heat indices
reaching into the 97-103 degree range this afternoon.

Early this morning, water vapor imagery showed a wave over Canada
tracking into northeast Montana. Models show this wave quickly
progressing southeastward through the day and it is expected to
strengthen enough to provide a southward push to the stalled out
frontal boundary by early this evening. Models are suggesting that initial
scattered thunderstorms will eventually develop into an MCS that will
track southeastward across much of northern and eastern Kansas
tonight and gradually diminishing during the overnight hours. With
ample daytime heating, expect MUCAPE values to reach upwards of
3000-4000J/kg. However, the region looks to remain capped through
much of the day and it even may be a struggle to break that cap
early this evening. As a result, cloud bases may be near 700mb with
fairly dry conditions in the low levels. The primary threats with
these storms will be damaging winds (as 0-6km bulk shear values
reach upwards of 45-55kts) and large hail. There is also the
potential for a few tornadoes, primarily near the Kansas/Nebraska
border as models show decent low-level SRH during the early to mid
evening hours with the approaching wave. Could also see some locally
heavy rainfall, especially across northeastern Kansas, as PWAT
values reach upwards of 2 inches. However, it`s worth noting that
the 3-hr flash flood guidance over that region is around 2.7-3.0
inches. As this front sinks southward over the region overnight,
temperatures should cool down behind the front with low temperatures
ranging from the upper 60s north to low 70s south.

.LONG TERM...(Tuesday through Sunday)
Issued at 311 AM CDT MON JUL 7 2014

Tuesday, the amplified upper level trough across the northern and
central plains will dig southeast into the upper Midwest and Great
Lakes States. A surface cold front will push southward across the
CWA through the morning hours. Most of the showers and thunderstorms
will have moved east across northern MO by 12Z. There may be a few
showers and thunderstorms during the morning hours across portions
of east central KS...generally southeast of the KS turnpike. The
low-level CAA will bring a cooler and drier airmass southward
across eastern KS. Highs will only reach the mid to upper 80s, may
see lower 80s along the NE border.

Tuesday night through Wednesday...a surface ridge of high pressure
will build southward across eastern KS. Expect dry conditions with
overnight lows in the lower to mid 60s. Highs on Wednesday will
reach the mid to upper 80s

Wednesday Night through Thursday night, The cold front across
central OK will begin to lift northward as a warm front. Deeper
moisture will beginning to advect north-northwest across central and
western KS. As the deeper moisture advect northward isentropic lift
combined with any ascent ahead of minor H5 troughs embedded within
the northwesterly flow aloft will provide the area with a chance for
showers and thunderstorms beginning late Wednesday night and
extending into Thursday night. Highs on Thursday will warm into the
upper 80s to around 90 degrees across much of the area.

Friday through Saturday, An upper level ridge will build east across
the southern plains. Expect mostly clear skies. High temperatures
will warm into the mid to upper 90s. overnight lows will only drop
into the mid to upper 70s.

Saturday night and Sunday...An upper level trough will amplify
across southern Canada and the Great Lakes states and will cause a
weak cold front to push southward into the northern counties of the
CWA. This may bring a chance for showers and thunderstorms for areas
north of I-70 late Saturday Night into Sunday. Highs Sunday will
reach the mid 90s south of I-70 with upper 80s along the NE


.AVIATION...(For the 12Z TAFs through 12Z Tuesday Morning)
Issued at 600 AM CDT MON JUL 7 2014

For the 12z TAFs, scattered showers and thunderstorms over northeast
Kansas are weakening as they progress southward, however still can
expect some storms with scattered MVFR cigs to pass near the TAF
sites this morning before diminishing by mid morning. Winds may
shift to the north with these storms, but expect the wind direction
to veer to the southeast through the day. A complex of storms is
expected to develop and track toward the TAF sites by early to mid
evening. Scattered activity should persist through the evening hours
but should diminish in coverage overnight into Tuesday morning. A cold
front associated with these storms will track south of the area,
causing winds to shift to the northeast and eventually toward the
north-northwest by Tuesday morning.




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