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Area forecast discussion 
National Weather Service Topeka Kansas
1246 PM CDT Thu Oct 2 2014

..update to aviation forecast discussion...

Short term...(today and tonight)
issued at 359 am CDT Thursday Oct 2 2014

Challenging forecast today. Water vapor loop shows significant
upper trough across the northern and Central High plains moving east
with a large area of lift ahead of it. Much of the clouds and
precipitation associated with the lift is in central and eastern
Nebraska this morning. Other storms are ongoing across OK into
southeast Kansas to central MO ahead of another weak wave.

As the main upper trough approaches the surface front/inverted
trough currently from south central Kansas into southeast Nebraska,
expect redevelopment of showers and thunderstorms across eastern Kansas
during the morning hours. Development along/ahead of cold front
would have some chance to be severe in east central Kansas early to
middle afternoon, with hail and wind the main hazards.

Short range models in pretty good agreement on timing of cold front
exiting our forecast area within an hour or so of 21z Thursday.
Synthetic radar imagery output from these models indicate showers
likely persisting for a few hours behind the front so have kept
chance pops in the southeast into the evening hours.

Water vapor loop shows next upper trough to affect area over
southern Alberta this morning. All models bring this southeastward
in northwest flow aloft with associated lift entering north central
Kansas counties late Thursday night. The shortwave is
weakening/losing amplitude as it moves through Nebraska, so would
expect a few hundredths at most from the dynamics associated with
this trough.

Temperatures tricky today with little to no rise expected behind the
boundary over north central Kansas and highs mainly in the 60s, but Max
temps reaching near 80 in the southeast before the front comes

Long term...(friday through wednesday)
issued at 359 am CDT Thursday Oct 2 2014

By Friday morning, models show a deep mid-level trough in place
across the central U.S. Models are in fairly good agreement in
having an embedded shortwave develop within this mid-level trough,
skimming across northern and northeastern Kansas Friday morning.
Model soundings show some saturation in the low to mid levels along
with some isentropic lift present, so could see some scattered
light precipitation develop. However, there doesn't look to be any
instability in the area so kept the mention of rain showers and
increased pops a bit during the morning hours with dry conditions
expected by the afternoon.

This deepening mid-level trough also will result in a surge of
colder air into the region. A tight pressure gradient will set up
across the region on Friday as surface high pressure quickly
advances into the area, resulting in breezy northwesterly winds
gusting upwards of 25-35mph. With this decent caa in place,
continued to trend cooler with Friday high temperatures, dropping
them into the mid/upper 50s. Chilly conditions are expected Friday
night into Saturday morning as light northwesterly flow remains in
place and skies become mostly clear. With these expected conditions,
much of the forecast area has the potential to see some patchy
frost develop by Saturday morning. Slightly warmer conditions are expected
on Saturday as the mid-level trough axis advances well east of the
area and surface winds back toward the east and southeast through
the day, resulting in highs ranging from the upper 50s to middle

Models show a weak cold front tracking eastward through the area on
Sunday, but do not anticipate any precipitation with this frontal
passage. There also does not look to be much in the way of colder
air behind this boundary, so have Sunday high temperatures reaching
into the upper 60s to middle 70s. Have added slight chance pops on
Monday for far eastern Kansas as a passing shortwave may produce a
few scattered showers. Otherwise, conditions are expected to remain
dry through the middle of next week with high temperatures
rebounding into the mid 70s to mid 80s and low temperatures rising
into the 50s and 60s as southwesterly surface winds return to the


Aviation...(for the 18z tafs through 18z Friday afternoon)
issued at 1226 PM CDT Thursday Oct 2 2014

Convective debris and lower cigs with sct thunderstorms and rain will hold in the IFR to
occasionally MVFR category before drier air across Nebraska clears
skies to VFR after 01z. A progressive wave passes just north of
terminals Friday morning with some indication of MVFR cigs developing.
Will introduce mention with some uncertainty on the strength of
the wave and available moisture. Strong north winds above 14 kts
persist thru afternoon aft 12z.


Top watches/warnings/advisories...


Short term...gdp
long term...hennecke

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