Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 012333

633 PM CDT Mon Jun 1 2015

...Update to aviation forecast discussion...

.SHORT TERM...(This Evening through Tuesday)
Issued at 335 PM CDT MON JUN 1 2015

Upper ridge continues to gradually build eastward, which will nudge
the surface high further into the Great Lakes region. This allows
more moisture within the return flow to spread into the area
overnight as the low level jet develops. The axis of the low level
jet appears to set up over central KS and NE. During the early
morning hours isentropic lift mainly on the 305 K surface along with
the return flow moisture could support isolated showers and possibly
a rumble of thunder. These elevated showers should be based around
5-7 kft, so it may be difficult to accumulate more than a hundredth
of precip. Also, not sure the extend of the coverage as well. These
showers look to form over central KS sometime around 3-5 am, and
begin to dissipate late morning as it approaches eastern KS when the
low level jet weakens. Several of the high res and larger scale
models support this scenario, therefore have added a slight chance
pop for that period. Clouds will be tough to get rid of through
tomorrow with the low level moisture advection, and boundary layer
moisture distribution. Some mixing out of the afternoon cloud cover
tomorrow should allow temps to reach the upper 70s to low 80s.

.LONG TERM...(Tuesday Night through Monday)
Issued at 335 PM CDT MON JUN 1 2015

Tuesday Night to Thursday...

On Tuesday night, short wave energy crossing the northern Plains
appears likely to initiate an MCS over northern Nebraska. Expect an
axis of modest MUCAPE to persist from central Nebraska into northern
KS through the night as the MCS propagates toward the southeast and
into the CAPE axis. Instability does seem likely to decrease with
eastward extent while forecast soundings indicate that the moist
layer at the top of the boundary layer may not be particularly
deep...indicating at least some potential for the MCS to become less
organized as it approaches northeast KS. Even still, have increase
thunderstorm chances before sunrise and into the late morning hours
mainly across northern Kansas. This system will impact the the rest
of the day on Wednesday as any residual cloud cover will limit
temperatures and residual outflow boundaries in the area could be
sufficient to initiate afternoon thunderstorms under the right
conditions. Low level moisture will certainly not be an issue for
Wednesday and beyond as surface dewpoints are likely to climb into
the upper 60s and perhaps lower 70s at any localized
heating along residual boundaries could lead to storm development
within an instability rich atmosphere. With this said, Wednesday
afternoon does not look like a slam dunk for thunderstorm
development but it is certainly possible. Deep layer shear is also
marginal for organization with any storms that were to develop.

Wednesday night into Thursday presents a similar scenario as an MCS
looks likely to develop on the High Plains over northeast Colorado
and western Nebraska and track toward northern KS overnight.
Overnight instability may be more ample on Wednesday night with some
evidence of a weak frontal boundary for an MCS to track along. If
these factors materialize, see some potential for severe storms late
Monday night into Thursday morning especially in northern KS. By
Thursday afternoon, there are substantial differences in mesoscale
phenomena over the forecast area, but the feel of the forecast is
that an outflow boundary and/or weak front will set up nearly
stationary in the vicinity of the forecast area with substantial
instability developing by late in the day. This will, of course,
depend on the behavior of any early MCS. 0-6 km shear vectors of 30
kts to perhaps a bit stronger are expected, although with
uncertainty in the overall strength of the mid level winds. Deep
shear seems to be the main question regarding severe potential late
Thursday, but at least see the potential for late day thunderstorm
development along the outflow/front to become severe. This will be a
period to watch closely as the mesoscale details unfold.

Thursday Night to Monday...

Models indicate convection developing to the north will push south
into the CWA Thursday evening associated with a frontal boundary.
NAM and ECMWF solution have 25-35kts of shear and over 3000 J/kg of
CAPE, suggesting storms could be severe with damaging winds and hail being
the primary hazards.  From here, the potential for storms persists
until the end of the period. With mesoscale features being the main
influence for storm formation, confidence with timing and locations
of these storms are low.  If any storms do develop over our area
Saturday or Sunday, storm parameters suggest they would have a
potential to be stronger.  Warm temperatures remain throughout the
period with highs in the 80s and lows around mid-60s.


.AVIATION...(For the 00Z TAFs through 00Z Tuesday Evening)
Issued at 628 PM CDT MON JUN 1 2015

Easterly winds continue through the period, becoming more
southeast with time. This should advect MVFR cigs back over the
area for the overnight hours, and expect this will break up around
midday tomorrow. Will need to watch for morning VCSH/VCTS near
MHK, but not high enough confidence for the TAF at this time.




SHORT TERM...Sanders
LONG TERM...Barjenbruch/Heller
AVIATION...67 is the U.S. government's official web portal to all federal, state and local government web resources and services.