Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 282323

National Weather Service Topeka KS
623 PM CDT THU APR 28 2016

...Update to aviation forecast discussion...

.SHORT TERM...(This Evening through Friday)
Issued at 336 PM CDT THU APR 28 2016

Clouds have held their ground across the northeastern counties as
cooler high pressure continues to move southeast into the Central
Plains.  Highs range from the 50s north to low 60s in our southern
counties so far.  Band of sprinkles or light rain has moved across
parts of Central Kansas this afternoon and should continue to move
north and dissipate over the next few hours.

Next chance for rain on a slow approach from the southwest and will
have cooler more stable air in place over our area to contend with.
Kept most areas dry until after midnight, then spread showers
eastward into sunrise.  Able to get some weak instability in the
southern counties that makes its way eastward into the afternoon,
but only enough to add isolated T at this time.  Cool lows tonight
in the 40s likely followed by cooler highs if clouds and rain hang
around for the afternoon. Went slightly cooler than guidance with
highs in the middle 50s northwest to low/mid 60s in the southeast
counties.  Points along the Neosho, Marais de Cygnes and the
Cottonwood river remain in or near flood stage, see related
hydrology products for details.

.LONG TERM...(Friday Night through Thursday)
Issued at 336 PM CDT THU APR 28 2016

Friday night through the weekend continues to look like an active
weather period in terms of multiple chances for precipitation.
Another strong, negatively-tilted trough will follow a track quite
similar to the system earlier this week. As opposed to the early
week system, local instability is not likely to be impressive owing
to widespread convective overturning and lesser boundary layer
moisture. That said, there will be rain and thunderstorms with the
best chance appearing to come Friday evening into early Saturday
morning as a strong vort max crosses northeast KS. Strong large-
scale vertical motion and modest instability in the area, along with
a deep moist airmass will contribute to periods of moderate to
perhaps heavy rainfall. However, the convective rain rates should
not be nearly as impressive as just a few days ago as the
instability will be much weaker and the system itself should be
fairly progressive from SW to NE. All told, would expect to see a
widespread 0.50" to 2" rainfall through Saturday morning. At the
current time, the flood threat seems to exist but does not warrant a
watch at this point due to the likelihood for mainly moderate rain
rates and only localized heavy amounts. A watch could be warranted
in the future if there is higher confidence in the heaviest precip
amounts falling over the same areas that received the heaviest rain
on Tuesday where stream flow remains elevated.

Saturday presents a bit of an interesting forecast as the GFS and
NAM build instability into eastern KS with a local surface low in
northeast KS and local low level convergence. This may allow for a
localized strong to severe weather threat to develop by the
afternoon, but there is much uncertainty regarding whether this will
in fact develop or not. For now, the severe potential is conditional
upon the location of the front/convergence actually being in the
local area, and if the threat develops it would likely be focused on
hail as the primary hazard. Shower chance linger into Saturday night
and Sunday, mainly in northern KS closer to the upper low.
Temperatures will cool quite a bit by Sunday with a high only in the
50s for much of the area but overnight clouds should keep the
diurnal difference to a minimum with lows in the 40s.

For the extended period from Monday through Thursday for the
upcoming week, a quiet and mainly dry period is expected to set up
over the Central Plains.  With mean Westerly flow regime off to the
north over Canada, and larger scale ridge set up over the Western
CONUS, perhaps the only factor that could cause very light precip
into Monday and Monday night is the passage of very broad positively
tilted trough axis extending over the area from the Great Lakes
region.  Did keep shower chances very slight for Monday.  Almost
completely eliminated these chances all together due to little lift,
low dewpoints and fairly dry sounding profiles with weak unorganized
wind fields but did keep along the points mainly west and south of
the Topeka vicinity for now. Ridging building over the Plains into
Tuesday and Wednesday should lead to a quiet weather pattern for the
work week ahead thereafter.

Meanwhile, temps slowly climb during the week from the mid 60s on
Monday into the mid 70s by Thursday.  Lows look to range from the
mid 40s Monday to the low 50s on Thursday.


.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 620 PM CDT THU APR 28 2016

VFR prevails this evening with some high clouds expected through
15Z while northerly winds below 10 kts veer to the northeast.
Incoming system from the southwest will initially have to overcome
drier air advecting over sites, creating less confidence in
widespread showers. For now, will mention VCSH aft 12Z and 15Z
respectively with models indicating MVFR cigs developing as the
low pressure area moves closer to the area towards 00Z.


.TOP Watches/Warnings/Advisories...


LONG TERM...Barjenbruch/Drake
AVIATION...Bowen is the U.S. government's official web portal to all federal, state and local government web resources and services.