Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 150841

341 AM CDT Mon Sep 15 2014

.SHORT TERM...(Today and Tonight)
Issued at 339 AM CDT MON SEP 15 2014

An upper level trough across the northern and central plains will
move eastward across the Great Lakes States Today. The stronger
ascent ahead of this trough was occuring across the upper Midwest
early this morning. The stronger isentropic lift was occuring from
eastern NE into northwest MO and western IA. This area of stronger
isentropic lift will also shift eastward across northern MO, IA and
into the mid and upper MS river valley through the morning hours.

A surface cold front was moving southward across northwest KS and
extend northeast into eastern NE. The front was located just north
of CNK. The front should move south of the CWA by 100 PM.

Most of the models are showing only a trace to one hundredths of an
inch of QPF across the CWA this morning and into the early afternoon
hours. Our best chance for an isolated shower will probably occur
behind the surface cold front as weak isentropic lift develops after
FROPA. The forecast soundings show a warm nose developing at 800mb
which may not allow any parcels to reach their LFC, so odds are we
may not get any elevated thunderstorms behind the front. But just in
case there may be enough lift I kept isolated thunderstorms directly
behind the surface cold front for the morning and early afternoon
hours. The capping inversion looks too strong for any surface based
storms to develop early this afternoon ahead of the surface cold
front across the southeast counties of the CWA.

Highs Today will reach the upper 70s to lower 80s across the
southeast counties during the early afternoon hours but should fall
back through the 70s once the surface cold front shifts winds to the
north. The central counties may see highs reach the upper 60s to
lower 70s by early afternoon, then remain steady through the
afternoon hours behind the cold front. The north central counties
will be behind the surface cold front during the mid morning hours,
with highs only warming back into the mid to upper 60s during the
afternoon hours.

Tonight, Skies will clear as a surface ridge of high pressure builds
southward across eastern KS through the night. Lows will drop into
the mid 40s along the NE border to around 50 across the southeast

.LONG TERM...(Tuesday through Sunday)
Issued at 339 AM CDT MON SEP 15 2014

As the upper trough in the eastern CONUS shifts eastward and the
intermountain west upper ridge amplifies...the moisture and cooler
air that had been pushed to the south and west will begin to edge
back to the northeast primarily late Tuesday night into Wednesday
night. At the same time...a couple of weak shortwave troughs will
move southeast through the flow aloft and across the area...interacting
with the increasing waa/isentropic lift to provide chances for
showers and thunderstorms through this period.

There should be a break in precip chances Thursday night through the
day Friday as drier air aloft advects in and a capping inversion
strengthens as the upper level ridge axis moves across the area. As
the northern portions of the west coast trough shears eastward into
the northern and central plains by Friday night and
Saturday...another cold front should approach then traverse the cwa
Saturday before pushing south and east of the area by late Sunday.
The combination of the frontal passage and shortwave trough in the
presence of deeper tropical moisture surging out of the southwestern
U.S. should aid the development of showers and thunderstorms for at
least the first half of the weekend.

Following highs in the upper 60s and lower 70s on Tuesday...temps
should moderate back into the 70s and lower 80s Wednesday and
Thursday...then primarily the 80s Friday into Saturday prior to
arrival of the weak cold front.


.AVIATION...(For the 06Z TAFs through 06Z Monday Night)
Issued at 1118 PM CDT SUN SEP 14 2014

00Z TOP RAOB showed 700 MB temps of +9C and new models runs show
this warm air aloft remaining over northeast KS for most of the
night. Now that the latest RAP and HRRR are trending dryer, do not
have enough confidence in carrying TS at the terminals. Still
looks like there could be a period of MVFR CIGS and VSBY behind
the FROPA and have not made any changes to this. Think that mixing
and some mid level clouds should prevent any stratus or fog from
forming ahead of the front, but this needs to be monitored.




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