Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 011049
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
549 AM CDT Fri Aug 1 2014

...AVIATION UPDATE...

.SHORT TERM...(Today and Tonight)
Issued at 249 AM CDT FRI AUG 1 2014

While not very obvious on the 07Z water vapor imagery, the model
solutions show a subtle shortwave moving south along the MO river.
The models also seem to pin point reasonable isentropic upglide with
saturation on the 305K surface over northeast KS where the scattered
showers are occurring now. Models show that what little PVA and
isentropic upglide there is this morning should dissipate or move to
the east of the area by noon today. So even with a well mixed
boundary layer and no real cap to a surface parcel, think weak
subsidence and a lack of lift in the low levels of the atmosphere
will prevent anything from developing this afternoon. The forecast
is for the isolated to scattered showers to linger through mid
morning before falling apart. The elevated instability is rather
modest based on the 00Z TOP RAOB, so think storms are not likely to
become much stronger than they already are. There should be good
insolation today and with little change in the airmass, I anticipate
highs to be similar to yesterday`s. Forecast soundings mix the
boundary layer to around 800MB and this would again warm temps into
the mid 80s in eastern KS to near 90 over central KS.

There appears to be a general lack of large scale forcing for
tonight. However the NAM and GFS again suggest there could be some
isentropic upglide developing. The model progs do not appear to be
as well organized as this morning which may be a result of no
subtle wave to focus the lift. At this point, precip chances appear
to be too small to mention in the forecast. However if later model
runs continue to show this isentropic lift overnight, some slight
chance POPs may need to be added. Lows tonight are forecast to fall
into the lower and middle 60s once again due to light winds and a
relatively dry airmass. Cloud cover could have an impact on lows if
in fact the isentropic lift materializes.

.LONG TERM...(Saturday through Thursday)
Issued at 249 AM CDT FRI AUG 1 2014

Little changes made to the previous forecast as model guidance
remains in agreement on the mid level ridge influencing the region
through early next week. A series of very weak vorticity maxima
traversing southeast throughout the weekend may produce periods of
increased cloud cover or isolated showers at best, given the amount
of subsidence in the area. Low confidence in location and coverage
warranted a dry forecast through Tuesday afternoon. Temperatures
through Wednesday are near seasonal norms in the upper 80s to low
90s. Overnight lows hover around 70 degrees.

Southerly flow increases by Tuesday as the next upper short wave
trough rounds the flattened ridge and tracks southeast across the
northern plains. Accompanied by a slow moving cold front, chances
for thunderstorms were introduced Tuesday evening with highest
probabilities over north central Kansas. Chances increase and spread
across much of the CWA Wednesday and Wednesday evening as the main
trough axis coincides with a fair amount of convergence along and
just ahead of the boundary. Scattered thunderstorms may redevelop
on Thursday especially south of Interstate 70 where the cold front
hangs up during the afternoon. Cooler temps and cloud cover will
fall back highs to the upper 80s Thursday.

&&

.AVIATION...(For the 12Z TAFs through 12Z Saturday Morning)
Issued at 549 AM CDT FRI AUG 1 2014

Based on latest radar trends, the back end of the elevated SHRA
looks to be east of TOP and FOE by 12Z. Predictability for
elevated SHRA tonight is to low to include in the forecast at this
time. Therefore expect VFR conditions will prevail with some mid
level clouds through the day. Winds could end up being light and
variable due to a weak meso low over the area.

&&

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

&&

$$

SHORT TERM...Wolters
LONG TERM...Bowen
AVIATION...Wolters






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